351 relations: AC power plugs and sockets, Adaptation (eye), Alarm clock, Alexander Meissner, Alexander Stepanovich Popov, Alexanderson alternator, All American Five, Alternating current, Alternator, AM broadcasting, AM stereo, Amateur radio, Amplifier, Amplitude, Amplitude modulation, Analog signal, Analogue electronics, Antenna (radio), Arc converter, Armstrong oscillator, Astronomical radio source, Audio frequency, Audio power amplifier, Audio signal, Audion, Autodyne, Automatic gain control, AV receiver, Édouard Branly, Baby monitor, Band III, Band-pass filter, Bandwidth (signal processing), Base station, Beat (acoustics), Beat (music), Beat frequency oscillator, Biasing, Bistability, Bit rate, Bluetooth, Boombox, Capacitance, Capacitor, Carrier wave, Cathode, CD player, Cell site, Ceramic resonator, Citizens band radio, ..., Cognitive radio, Coherer, Collision avoidance system, Commercial broadcasting, Communications receiver, Communications satellite, Computer, Consumer electronics, Continuous wave, Control system, Coordinated Universal Time, Cordless telephone, Cryogenics, Crystal detector, Crystal filter, Crystal radio, Cutoff voltage, Damped wave, DC bias, Demodulation, Detector (radio), Dielectric wireless receiver, Digital audio broadcasting, Digital data, Digital signal, Digital signal processing, Diode, Dipole antenna, Direct current, Direct-conversion receiver, Display device, Distortion, Duplex (telecommunications), Edwin Howard Armstrong, Electric battery, Electric bell, Electric current, Electric field, Electric power, Electric spark, Electrical impedance, Electrical junction, Electrical resistance and conductance, Electrolytic detector, Electromagnet, Electromagnetic interference, Electromagnetic radiation, Electromagnetism, Electron, Electronic circuit, Electronic filter, Electronic oscillator, Electronic program guide, Envelope detector, Ernest Rutherford, Ernst Alexanderson, Fading, Feedback, Fidelity, Firmware, Flash memory, Fleming valve, FM broadcast band, FM broadcasting, Frequency, Frequency mixer, Frequency modulation, Frequency response, Frog legs, Gain (electronics), Galena, Galvanometer, Garage door opener, Geissler tube, General Electric, Geostationary orbit, Geosynchronous orbit, Global Positioning System, GNU Radio, Golden Age of Radio, Google Earth, GPS navigation device, Graphical user interface, Greenleaf Whittier Pickard, Grid-leak detector, Ground station, Guglielmo Marconi, Handset, Headphones, Heinrich Hertz, Hertz, Heterodyne, High fidelity, High frequency, Home audio, Home cinema, Horn loudspeaker, Human brain, Human eye, Hysteresis, Impedance matching, Incandescent light bulb, Inductance, Inductive coupling, Inductor, Institute of Radio Engineers, Integrated circuit, Intermediate frequency, Interplanetary spaceflight, Inverted-F antenna, Ionization, Irving Langmuir, John Ambrose Fleming, John Stone Stone, Karl Ferdinand Braun, Ku band, L band, Landline, LC circuit, Lead sulfide, Lee de Forest, Line-of-sight propagation, Liquid nitrogen, Local oscillator, Longwave, Loop antenna, Loop gain, Loudness, Loudspeaker, Louis Alan Hazeltine, Low frequency, Low-pass filter, Magic eye tube, Magnet, Magnetic detector, Magnetic field, Measuring receiver, Medium frequency, Microphone, Microprocessor, Microwave, Microwave transmission, Minimum detectable signal, Mir Publishers, Mobile broadband modem, Mobile phone, Modulation, Monaural, Monopole antenna, Morse code, Moscow, Multipath interference, NASA Deep Space Network, Neutrodyne, News broadcasting, Nikola Tesla, Nitric acid, Noise (electronics), Noise (radio), Oil well, Oliver Lodge, Parabolic antenna, Parasitic oscillation, Passband, Pentode, Phase (waves), Plate electrode, Poldhu, Portable media player, Positive feedback, Potentiometer, Punched tape, Push-to-talk, Q factor, Quartz, Radar, Radio, Radio astronomy, Radio atmospheric, Radio broadcasting, Radio frequency, Radio propagation, Radio receiver, Radio spectrum, Radio station, Radio telescope, Radio wave, Radio-controlled model, Radiogram (device), Radiolocation, Radiotelephone, Receiver (information theory), Rectifier, Reflex receiver, Regenerative circuit, Reginald Fessenden, Relay, Remote control, Remote keyless system, Remote sensing, Resonance, RF front end, RMS Titanic, Router (computing), Rudolf Goldschmidt, Satellite, Satellite dish, Satellite navigation, Satellite radio, Satellite television, Scanner (radio), Schottky diode, Selectivity (electronic), Semiconductor device, Sensitivity (electronics), Set-top box, Shell (projectile), Shortwave listening, Shortwave radio, Shortwave radio receiver, Sideband, Signal corps, Signal strength in telecommunications, Signal-to-noise ratio, Silicon carbide, Sine wave, Single-sideband modulation, Software, Software-defined radio, Sound, Spacecraft, Spark gap, Spark-gap transmitter, Spectral density, Spectrum analyzer, Speech synthesis, St. John's, Newfoundland and Labrador, Stereophonic sound, Superheterodyne receiver, Supreme Court of the United States, Surface acoustic wave, Surface wave, Syphon recorder, Table radio, Talk radio, Telecommunication, Telecommunications link, Telegraph key, Telemetry, Telephone, Telephone company, Telephone network, Television, Television antenna, Television channel, Television receive-only, Television set, Television station, Terrestrial television, Tetrode, Thermionic emission, Thomas Edison, Tikker, Tone control circuit, Transceiver, Transducer, Transfer function, Transformer types, Transistor, Transistor radio, Transmitter, Transponder (satellite communications), Triode, Tuned radio frequency receiver, Tuner (radio), Tuning fork, Two-way radio, Ultra high frequency, Unmanned aerial vehicle, Vacuum tube, Valdemar Poulsen, Vehicle audio, Very high frequency, VHF omnidirectional range, Video, Volt, Voltage, Walkie-talkie, Watt, Well logging, Western Electric, Whip antenna, Wide area network, Wildlife management, William Crookes, Wireless access point, Wireless LAN, Wireless microphone, Wireless power transfer, Wireless telegraphy, World War I. 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AC power plugs and sockets are devices that allow electrically operated equipment to be connected to the primary alternating current (AC) power supply in a building.
In ocular physiology, adaptation is the ability of the eye to adjust to various levels of light.
An alarm clock (or sometimes just an alarm) is a clock that is designed to alert an individual or group of individuals at specified time.
Alexander Meissner (in German: Alexander Meißner) (September 14, 1883 – January 3, 1958) was Austrian engineer and physicist.
Alexander Stepanovich Popov (sometimes spelled Popoff; Алекса́ндр Степа́нович Попо́в; –) was a Russian physicist who is acclaimed in his homeland and some eastern European countries as the inventor of radio.
An Alexanderson alternator is a rotating machine invented by Ernst Alexanderson in 1904 for the generation of high-frequency alternating current for use as a radio transmitter.
The term All American Five (abbreviated AA5) is a colloquial name for mass-produced, superheterodyne radio receivers that used five vacuum tubes in their design.
Alternating current (AC) is an electric current which periodically reverses direction, in contrast to direct current (DC) which flows only in one direction.
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current.
AM broadcasting is a radio broadcasting technology, which employs amplitude modulation (AM) transmissions.
AM stereo is a term given to a series of mutually incompatible techniques for radio broadcasting stereo audio in the AM band in a manner that is compatible with standard AM receivers.
Amateur radio, also known as ham radio, describes the use of radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communication.
An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the power of a signal (a time-varying voltage or current).
The amplitude of a periodic variable is a measure of its change over a single period (such as time or spatial period).
Amplitude modulation (AM) is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave.
An analog signal is any continuous signal for which the time varying feature (variable) of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal.
Analogue electronics (also spelled analog electronics) are electronic systems with a continuously variable signal, in contrast to digital electronics where signals usually take only two levels.
In radio, an antenna is the interface between radio waves propagating through space and electric currents moving in metal conductors, used with a transmitter or receiver.
The arc converter, sometimes called the arc transmitter, or Poulsen arc after Danish engineer Valdemar Poulsen who invented it in 1903, was a variety of spark transmitter used in early wireless telegraphy.
The Armstrong oscillator (also known as the Meissner oscillator) is an electronic oscillator circuit which uses an inductor and capacitor to generate an oscillation.
Astronomical radio sources are objects in outer space that emit strong radio waves.
An audio frequency (abbreviation: AF) or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human.
An audio power amplifier (or power amp) is an electronic amplifier that reproduces low-power electronic audio signals such as the signal from radio receiver or electric guitar pickup at a level that is strong enough for driving (or powering) loudspeakers or headphones.
An audio signal is a representation of sound, typically as an electrical voltage for analog signals and a binary number for digital signals.
The Audion was an electronic detecting or amplifying vacuum tube invented by American electrical engineer Lee de Forest in 1906.
The autodyne circuit was an improvement to radio signal amplification using the De Forest Audion vacuum tube amplifier.
Automatic gain control (AGC), also called automatic volume control (AVC), is a closed-loop feedback regulating circuit in an amplifier or chain of amplifiers, the purpose of which is to maintain a suitable signal amplitude at its output, despite variation of the signal amplitude at the input.
An audio/video receiver (AVR) is a consumer electronics component used in a home theater.
Édouard Eugène Désiré Branly (23 October 1844 – 24 March 1940) was a French inventor, physicist and professor at the Institut Catholique de Paris.
A baby monitor, also known as a baby alarm, is a radio system used to remotely listen to sounds made by an infant.
Band III is the name of the range of radio frequencies within the very high frequency (VHF) part of the electromagnetic spectrum from 174 to 240 megahertz (MHz).
A band-pass filter, also bandpass filter or BPF, is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range.
Bandwidth is the difference between the upper and lower frequencies in a continuous band of frequencies.
Base station (or base radio station) is – according to the International Telecommunication Union's (ITU) Radio Regulations (RR) – a "land station in the land mobile service." The term is used in the context of mobile telephony, wireless computer networking and other wireless communications and in land surveying.
In acoustics, a beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies.
In music and music theory, the beat is the basic unit of time, the pulse (regularly repeating event), of the mensural level (or beat level).
In a radio receiver, a beat frequency oscillator or BFO is a dedicated oscillator used to create an audio frequency signal from Morse code radiotelegraphy (CW) transmissions to make them audible.
Biasing in electronics means establishing predetermined voltages or currents at various points of an electronic circuit for the purpose of establishing proper operating conditions in electronic components.
In a dynamical system, bistability means the system has two stable equilibrium states.
In telecommunications and computing, bit rate (bitrate or as a variable R) is the number of bits that are conveyed or processed per unit of time.
Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength UHF radio waves in the ISM band from 2.4 to 2.485GHz) from fixed and mobile devices, and building personal area networks (PANs).
A boombox is a transistorized portable music player featuring one or two cassette tape recorder/players and AM/FM radio, generally with a carrying handle.
Capacitance is the ratio of the change in an electric charge in a system to the corresponding change in its electric potential.
A capacitor is a passive two-terminal electrical component that stores potential energy in an electric field.
In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an input signal for the purpose of conveying information.
A cathode is the electrode from which a conventional current leaves a polarized electrical device.
A CD player is an electronic device that plays audio compact discs, which are a digital optical disc data storage format.
A cell site or cell tower is a cellular-enabled mobile device site where antennae and electronic communications equipment are placed — typically on a radio mast, tower, or other raised structure — to create a cell (or adjacent cells) in a cellular network.
A ceramic resonator is an electronic component consisting of a piece of a piezoelectric ceramic material with two or more metal electrodes attached.
Citizens band radio (also known as CB radio) is, in many countries, a system of short-distance radio communications between individuals typically on a selection of 40 channels within the 27 MHz (11 m) band.
A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion.
The coherer was a primitive form of radio signal detector used in the first radio receivers during the wireless telegraphy era at the beginning of the 20th century.
A collision avoidance system is an automobile safety system designed to prevent or reduce the severity of a collision.
Commercial broadcasting (also called private broadcasting) is the broadcasting of television programs and radio programming by privately owned corporate media, as opposed to state sponsorship.
A communications receiver is a type of radio receiver used as a component of a radio communication link.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth.
A computer is a device that can be instructed to carry out sequences of arithmetic or logical operations automatically via computer programming.
Consumer electronics or home electronics are electronic (analog or digital) equipments intended for everyday use, typically in private homes.
A continuous wave or continuous waveform (CW) is an electromagnetic wave of constant amplitude and frequency, almost always a sine wave, that for mathematical analysis is considered to be of infinite duration.
A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops.
A cordless telephone or portable telephone is a telephone in which the handset is portable and communicates with the body of the phone by radio, instead of being attached by a cord.
In physics, cryogenics is the production and behaviour of materials at very low temperatures.
A crystal detector is an obsolete electronic component in some early 20th century radio receivers that used a piece of crystalline mineral as a detector (demodulator) to rectify the alternating current radio signal to extract the audio modulation which produced the sound in the earphones.
A crystal filter is an electronic filter that uses quartz crystals for resonators.
A crystal radio receiver, also called a crystal set, is a simple radio receiver, popular in the early days of radio.
In electronics, the cut-off voltage is the voltage at which a battery is considered fully discharged, beyond which further discharge could cause harm.
A damped wave is a wave whose amplitude of oscillation decreases with time, eventually going to zero, an exponentially decaying sinusoidal wave.
When describing a periodic function in the time domain, the DC bias, DC component, DC offset, or DC coefficient is the mean amplitude of the waveform.
Demodulation is extracting the original information-bearing signal from a carrier wave.
In radio, a detector is a device or circuit that extracts information from a modulated radio frequency current or voltage.
Dielectric wireless receiver is a type of radiofrequency receiver front-end featuring a complete absence of electronic circuitry and metal interconnects.
Digital audio broadcasting (DAB) is a digital radio standard for broadcasting digital audio radio services, used in many countries across Europe, Asia, and the Pacific.
Digital data, in information theory and information systems, is the discrete, discontinuous representation of information or works.
A digital signal is a signal that is being used to represent data as a sequence of discrete values; at any given time it can only take on one of a finite number of values.
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations.
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other.
In radio and telecommunications a dipole antenna or doublet is the simplest and most widely used class of antenna.
Direct current (DC) is the unidirectional flow of electric charge.
A direct-conversion receiver (DCR), also known as homodyne, synchrodyne, or zero-IF receiver, is a radio receiver design that demodulates the incoming radio signal using synchronous detection driven by a local oscillator whose frequency is identical to, or very close to the carrier frequency of the intended signal.
A display device is an output device for presentation of information in visual or tactile form (the latter used for example in tactile electronic displays for blind people).
Distortion is the alteration of the original shape (or other characteristic) of something.
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions.
Edwin Howard Armstrong (December 18, 1890 – February 1, 1954) was an American electrical engineer and inventor, best known for developing FM (frequency modulation) radio and the superheterodyne receiver system.
An electric battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, smartphones, and electric cars.
An electric bell is a mechanical bell that functions by means of an electromagnet.
An electric current is a flow of electric charge.
An electric field is a vector field surrounding an electric charge that exerts force on other charges, attracting or repelling them.
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit.
An electric spark is an abrupt electrical discharge that occurs when a sufficiently high electric field creates an ionized, electrically conductive channel through a normally-insulating medium, often air or other gases or gas mixtures.
Electrical impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied.
An electrical junction may be either a thermoelectricity junction, a metal–semiconductor junction or a p–n junction (p-type semiconductor–n-type semiconductor junction).
The electrical resistance of an electrical conductor is a measure of the difficulty to pass an electric current through that conductor.
The electrolytic detector, or liquid barretter, was a type of detector (demodulator) used in early radio receivers.
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction.
In physics, electromagnetic radiation (EM radiation or EMR) refers to the waves (or their quanta, photons) of the electromagnetic field, propagating (radiating) through space-time, carrying electromagnetic radiant energy.
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles.
The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.
An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow.
Electronic filters are circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both.
An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave.
Electronic program guides (EPGs) and interactive program guides (IPGs) are menu-based systems that provide users of television, radio and other media applications with continuously updated menus displaying broadcast programming (TV listings in the UK) or scheduling information for current and upcoming programming.
An envelope detector is an electronic circuit that takes a high-frequency signal as input and provides an output which is the envelope of the original signal.
Ernest Rutherford, 1st Baron Rutherford of Nelson, HFRSE LLD (30 August 1871 – 19 October 1937) was a New Zealand-born British physicist who came to be known as the father of nuclear physics.
Ernst Frederick Werner Alexanderson (January 25, 1878 – May 14, 1975) was a Swedish-American electrical engineer, who was a pioneer in radio and television development.
In wireless communications, fading is variation or the attenuation of a signal with various variables.
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop.
Fidelity is the quality of faithfulness or loyalty.
In electronic systems and computing, firmware is a specific class of computer software that provides the low-level control for the device's specific hardware.
Flash memory is an electronic (solid-state) non-volatile computer storage medium that can be electrically erased and reprogrammed.
The Fleming valve, also called the Fleming oscillation valve, was a thermionic valve or vacuum tube invented in 1904 by Englishman John Ambrose Fleming as a detector for early radio receivers used in electromagnetic wireless telegraphy.
The FM broadcast band, used for FM broadcast radio by radio stations, differs between different parts of the world.
FM broadcasting is a method of radio broadcasting using frequency modulation (FM) technology.
Frequency is the number of occurrences of a repeating event per unit of time.
In electronics, a mixer, or frequency mixer, is a nonlinear electrical circuit that creates new frequencies from two signals applied to it.
In telecommunications and signal processing, frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave.
Frequency response is the quantitative measure of the output spectrum of a system or device in response to a stimulus, and is used to characterize the dynamics of the system.
Frog legs are one of the better-known delicacies of French and Chinese cuisine.
In electronics, gain is a measure of the ability of a two-port circuit (often an amplifier) to increase the power or amplitude of a signal from the input to the output port by adding energy converted from some power supply to the signal.
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide.
A galvanometer is an electromechanical instrument used for detecting and indicating electric current.
A garage door opener is a motorized device that opens and closes garage doors.
A Geissler tube is an early gas discharge tube used to demonstrate the principles of electrical glow discharge, similar to modern neon lighting.
General Electric Company (GE) is an American multinational conglomerate incorporated in New York and headquartered in Boston, Massachusetts.
A geostationary orbit, often referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit above Earth's equator and following the direction of Earth's rotation.
A geosynchronous orbit (sometimes abbreviated GSO) is an orbit around Earth of a satellite with an orbital period that matches Earth's rotation on its axis, which takes one sidereal day (23 hours, 56 minutes, and 4 seconds).
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Air Force.
GNU Radio is a free software development toolkit that provides signal processing blocks to implement software-defined radios and signal-processing systems.
The old-time radio era, sometimes referred to as the Golden Age of Radio, was an era of radio programming in the United States during which radio was the dominant electronic home entertainment medium.
Google Earth is a computer program that renders a 3D representation of Earth based on satellite imagery.
A GPS navigation device, GPS receiver, or simply GPS is a device that is capable of receiving information from GPS satellites and then to calculate the device's geographical position.
The graphical user interface (GUI), is a type of user interface that allows users to interact with electronic devices through graphical icons and visual indicators such as secondary notation, instead of text-based user interfaces, typed command labels or text navigation.
Greenleaf Whittier Pickard (February 14, 1877, Portland, Maine – January 8, 1956, Newton, Massachusetts) was a United States radio pioneer.
A grid leak detector is an electronic circuit that demodulates an amplitude modulated alternating current and amplifies the recovered modulating voltage.
A ground station, earth station, or earth terminal is a terrestrial radio station designed for extraplanetary telecommunication with spacecraft (constituting part of the ground segment of the spacecraft system), or reception of radio waves from astronomical radio sources.
Guglielmo Marconi, 1st Marquis of Marconi (25 April 187420 July 1937) was an Italian inventor and electrical engineer known for his pioneering work on long-distance radio transmission and for his development of Marconi's law and a radio telegraph system.
A handset is a component of a telephone that a user holds to the ear and mouth to receive audio through the receiver and speak to the remote party via the built-in transmitter.
Headphones (or head-phones in the early days of telephony and radio) are a pair of small loudspeaker drivers worn on or around the head over a user's ears.
Heinrich Rudolf Hertz (22 February 1857 – 1 January 1894) was a German physicist who first conclusively proved the existence of the electromagnetic waves theorized by James Clerk Maxwell's electromagnetic theory of light.
The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second.
Heterodyning is a signal processing technique invented in 1901 by Canadian inventor-engineer Reginald Fessenden that creates new frequencies by combining or mixing two frequencies.
High fidelity (often shortened to hi-fi or hifi) is a term used by listeners, audiophiles and home audio enthusiasts to refer to high-quality reproduction of sound.
High frequency (HF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) between 3 and 30 megahertz (MHz).
Home audio systems are audio electronics intended for home entertainment use, such as shelf stereos and surround sound receivers.
Home cinema, also called home theater or home theatre, refers to home entertainment audio-visual systems that seek to reproduce a movie theater experience and mood using consumer electronics-grade video and audio equipment that is set up in a room or backyard of a private home.
A horn loudspeaker is a loudspeaker or loudspeaker element which uses an acoustic horn to increase the overall efficiency of the driving element(s).
The human brain is the central organ of the human nervous system, and with the spinal cord makes up the central nervous system.
The human eye is an organ which reacts to light and pressure.
Hysteresis is the dependence of the state of a system on its history.
In electronics, impedance matching is the practice of designing the input impedance of an electrical load or the output impedance of its corresponding signal source to maximize the power transfer or minimize signal reflection from the load.
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to such a high temperature that it glows with visible light (incandescence).
In electromagnetism and electronics, inductance is the property of an electrical conductor by which a change in electric current through it induces an electromotive force (voltage) in the conductor.
In electrical engineering, two conductors are referred to as inductively coupled or magnetically coupled when they are configured such that a change in current through one wire induces a voltage across the ends of the other wire through electromagnetic induction.
An inductor, also called a coil, choke or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it.
The Institute of Radio Engineers (IRE) was a professional organization which existed from 1912 until December 31, 1962.
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, normally silicon.
In communications and electronic engineering, an intermediate frequency (IF) is a frequency to which a carrier wave is shifted as an intermediate step in transmission or reception.
Interplanetary spaceflight or interplanetary travel is travel between planets, usually within a single planetary system.
An inverted-F antenna is a type of antenna used in wireless communication.
Ionization or ionisation, is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.
Irving Langmuir (January 31, 1881 – August 16, 1957) was an American chemist and physicist.
Sir John Ambrose Fleming FRS (29 November 1849 – 18 April 1945), an English electrical engineer and physicist, invented the first thermionic valve or vacuum tube, and also established the left-hand rule for electric motors.
John Stone Stone (September 24, 1869 – May 20, 1943) was an American mathematician, physicist and inventor.
Karl Ferdinand Braun (6 June 1850 – 20 April 1918) was a German inventor, physicist and Nobel laureate in physics.
The Ku band is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz).
The L band is the Institute of Electrical and Electronics Engineers (IEEE) designation for the range of frequencies in the radio spectrum from 1 to 2 gigahertz (GHz).
A landline telephone (also known as land line, land-line, main line, home phone, landline, fixed-line, and wireline) is a phone that uses a metal wire or optical fiber telephone line for transmission as distinguished from a mobile cellular line, which uses radio waves for transmission.
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together.
Lead sulfide refers to two compounds containing lead and sulfur.
Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor, self-described "Father of Radio", and a pioneer in the development of sound-on-film recording used for motion pictures.
Line-of-sight propagation is a characteristic of electromagnetic radiation or acoustic wave propagation which means waves travel in a direct path from the source to the receiver.
Liquid nitrogen is nitrogen in a liquid state at an extremely low temperature.
In electronics, a local oscillator (LO) is an electronic oscillator used with a mixer to change the frequency of a signal.
In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band.
A loop antenna is a radio antenna consisting of a loop or coil of wire, tubing, or other electrical conductor usually fed by a balanced source or feeding a balanced load.
In electronics and control system theory, loop gain is the sum of the gain, expressed as a ratio or in decibels, around a feedback loop.
In acoustics, loudness is the subjective perception of sound pressure.
A loudspeaker (or loud-speaker or speaker) is an electroacoustic transducer; which converts an electrical audio signal into a corresponding sound.
Louis Alan Hazeltine (August 7, 1886 – May 24, 1964) was an engineer and physicist, the inventor of the Neutrodyne circuit, and the Hazeltine-Fremodyne Superregenerative circuit.
Low frequency (low freq) or LF is the ITU designation for radio frequencies (RF) in the range of 30 kilohertz (kHz)–300 kHz.
A low-pass filter (LPF) is a filter that passes signals with a frequency lower than a certain cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency.
A magic eye tube or tuning indicator, in technical literature called an electron-ray indicator tube, is a vacuum tube which gives a visual indication of the amplitude of an electronic signal, such as an audio output, radio-frequency signal strength, or other functions.
A magnet is a material or object that produces a magnetic field.
The magnetic detector or Marconi magnetic detector, sometimes called the "Maggie", was an early radio wave detector used in some of the first radio receivers to receive Morse code messages during the wireless telegraphy era around the turn of the 20th century.
A magnetic field is a vector field that describes the magnetic influence of electrical currents and magnetized materials.
In telecommunication, a measuring receiver or measurement receiver is a calibrated laboratory-grade radio receiver designed to measure the characteristics of radio signals.
Medium frequency (MF) is the ITU designation for radio frequencies (RF) in the range of 300 kilohertz (kHz) to 3 megahertz (MHz).
A microphone, colloquially nicknamed mic or mike, is a transducer that converts sound into an electrical signal.
A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single integrated circuit (IC), or at most a few integrated circuits.
Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between and.
Microwave transmission is the transmission of information or energy by microwave radio waves.
A minimum detectable signal is a signal at the input of a system whose power produces a signal-to-noise ratio of m at the output.
Mir Publishers (Издательство "Мир") was a major publishing house in the Soviet Union which continues to exist in modern Russian Federation.
A mobile broadband modem, also known as a connect card or data card, is a type of modem that allows a personal computer or a router to receive Internet access via a mobile broadband connection instead of using telephone or cable television lines.
A mobile phone, known as a cell phone in North America, is a portable telephone that can make and receive calls over a radio frequency link while the user is moving within a telephone service area.
In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted.
Monaural or monophonic sound reproduction (often shortened to mono) is sound intended to be heard as if it were emanating from one position.
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane.
Morse code is a method of transmitting text information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment.
Moscow (a) is the capital and most populous city of Russia, with 13.2 million residents within the city limits and 17.1 million within the urban area.
Multipath interference is a phenomenon in the physics of waves whereby a wave from a source travels to a detector via two or more paths and, under the right condition, the two (or more) components of the wave interfere.
The NASA Deep Space Network (DSN) is a worldwide network of US spacecraft communication facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports NASA's interplanetary spacecraft missions.
The Neutrodyne radio receiver, invented in 1922 by Louis Hazeltine, was a particular type of tuned radio frequency (TRF) receiver, in which the instability-causing inter-electrode capacitance of the triode RF tubes is cancelled out or "neutralized".
News broadcasting is the medium of broadcasting of various news events and other information via television, radio, or internet in the field of broadcast journalism.
Nikola Tesla (Никола Тесла; 10 July 1856 – 7 January 1943) was a Serbian-American inventor, electrical engineer, mechanical engineer, physicist, and futurist who is best known for his contributions to the design of the modern alternating current (AC) electricity supply system.
Nitric acid (HNO3), also known as aqua fortis (Latin for "strong water") and spirit of niter, is a highly corrosive mineral acid.
In electronics, noise is an unwanted disturbance in an electrical signal.
In radio reception, noise is the superposition of white noise and other disturbing influences on the signal, caused either by thermal noise and other electronic noise from receiver input circuits or by interference from radiated electromagnetic noise picked up by the receiver's antenna.
An oil well is a boring in the Earth that is designed to bring petroleum oil hydrocarbons to the surface.
Sir Oliver Joseph Lodge, (12 June 1851 – 22 August 1940) was a British physicist and writer involved in the development of, and holder of key patents for, radio.
A parabolic antenna is an antenna that uses a parabolic reflector, a curved surface with the cross-sectional shape of a parabola, to direct the radio waves.
Parasitic oscillation is an undesirable electronic oscillation (cyclic variation in output voltage or current) in an electronic or digital device.
A passband is the range of frequencies or wavelengths that can pass through a filter.
A pentode is an electronic device having five active electrodes.
Phase is the position of a point in time (an instant) on a waveform cycle.
A plate, usually called anode in Britain, is a type of electrode that forms part of a vacuum tube.
Poldhu is a small area in south Cornwall, England, UK, situated on the Lizard Peninsula; it comprises Poldhu Point and Poldhu Cove.
A portable media player (PMP) or digital audio player (DAP) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files.
Positive feedback is a process that occurs in a feedback loop in which the effects of a small disturbance on a system include an increase in the magnitude of the perturbation.
A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider.
Punched tape or perforated paper tape is a form of data storage, consisting of a long strip of paper in which holes are punched to store data.
Push-to-talk (PTT), also known as press-to-transmit, is a method of having conversations or talking on half-duplex communication lines, including two-way radio, using a momentary button to switch from voice reception mode to transmit mode.
In physics and engineering the quality factor or Q factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its centre frequency.
Quartz is a mineral composed of silicon and oxygen atoms in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2.
Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects.
Radio is the technology of using radio waves to carry information, such as sound, by systematically modulating properties of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width.
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies.
A radio atmospheric signal or sferic (sometimes also spelled "spheric") is a broadband electromagnetic impulse that occurs as a result of natural atmospheric lightning discharges.
Radio broadcasting is transmission by radio waves intended to reach a wide audience.
Radio frequency (RF) refers to oscillatory change in voltage or current in a circuit, waveguide or transmission line in the range extending from around twenty thousand times per second to around three hundred billion times per second, roughly between the upper limit of audio and the lower limit of infrared.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another, or into various parts of the atmosphere.
In radio communications, a radio receiver (receiver or simply radio) is an electronic device that receives radio waves and converts the information carried by them to a usable form.
The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3 000 GHz (3 THz).
A radio station is a set of equipment necessary to carry on communication via radio waves.
A radio telescope is a specialized antenna and radio receiver used to receive radio waves from astronomical radio sources in the sky in radio astronomy.
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
A radio-controlled model (or RC model) is a model that is steerable with the use of radio control.
In British English, a radiogram is a piece of furniture that combined a radio and record player.
Radiolocating is the process of finding the location of something through the use of radio waves.
A radiotelephone (or radiophone) is a communications system for transmission of speech over radio.
The receiver in information theory is the receiving end of a communication channel.
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction.
A reflex radio receiver, occasionally called a reflectional receiver, is a radio receiver design in which the same amplifier is used to amplify the high-frequency radio signal (RF) and low-frequency audio (sound) signal (AF).
A regenerative circuit is an amplifier circuit that employs positive feedback (also known as regeneration); some of the output of the amplifying device is applied to its input without phase inversion, which reinforces the signal, increasing the amplification.
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father.
A relay is an electrically operated switch.
In electronics, a remote control or clicker is a component of an electronic device used to operate the device from a distance, usually wirelessly.
A keyless entry system is an electronic lock that controls access to a building or vehicle without using a traditional mechanical key.
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation.
In physics, resonance is a phenomenon in which a vibrating system or external force drives another system to oscillate with greater amplitude at specific frequencies.
In a radio receiver circuit, the RF front end is a generic term for all the circuitry between the antenna up to and including the mixer stage.
RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean in the early hours of 15 April 1912, after colliding with an iceberg during its maiden voyage from Southampton to New York City.
A router is a networking device that forwards data packets between computer networks.
Rudolf Goldschmidt (March 19, 1876, Neubukow, Mecklenburg – 1950, London) was a German engineer and inventor.
In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit.
A satellite dish is a dish-shaped type of parabolic antenna designed to receive or transmit information by radio waves to or from a communication satellite.
A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning.
Satellite radio is defined by the International Telecommunication Union (ITU)'S ITU Radio Regulations (RR) as a broadcasting-satellite service.
Satellite television is a service that delivers television programming to viewers by relaying it from a communications satellite orbiting the Earth directly to the viewer's location.
A scanner (also referred to a police scanner, police scanner radio or radio scanner) is a radio receiver that can automatically tune, or scan, two or more discrete frequencies, stopping when it finds a signal on one of them and then continuing to scan other frequencies when the initial transmission ceases.
The Schottky diode (named after the German physicist Walter H. Schottky), also known as Schottky barrier diode or hot-carrier diode, is a semiconductor diode formed by the junction of a semiconductor with a metal.
Selectivity is a measure of the performance of a radio receiver to respond only to the radio signal it is tuned to (such as a radio station) and reject other signals nearby in frequency, such as another broadcast on an adjacent channel.
Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide, as well as organic semiconductors.
The sensitivity of an electronic device, such as a communications system receiver, or detection device, such as a PIN diode, is the minimum magnitude of input signal required to produce a specified output signal having a specified signal-to-noise ratio, or other specified criteria.
A set-top box (STB) or set-top unit (STU) (one type also colloquially known as a cable box) is an information appliance device that generally contains a TV-tuner input and displays output to a television set and an external source of signal, turning the source signal into content in a form that then be displayed on the television screen or other display device.
A shell is a payload-carrying projectile that, as opposed to shot, contains an explosive or other filling, though modern usage sometimes includes large solid projectiles properly termed shot.
Shortwave listening, or SWLing, is the hobby of listening to shortwave radio broadcasts located on frequencies between 1700 kHz and 30 MHz.
Shortwave radio is radio transmission using shortwave radio frequencies.
A shortwave radio receiver is a radio receiver that can receive one or more shortwave bands, between 1.6 and 30 MHz.
In radio communications, a sideband is a band of frequencies higher than or lower than the carrier frequency, containing power as a result of the modulation process.
A signal corps is a military branch, responsible for military communications (signals).
In telecommunications, particularly in radio frequency, signal strength (also referred to as field strength) refers to the transmitter power output as received by a reference antenna at a distance from the transmitting antenna.
Signal-to-noise ratio (abbreviated SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise.
Silicon carbide (SiC), also known as carborundum, is a semiconductor containing silicon and carbon.
A sine wave or sinusoid is a mathematical curve that describes a smooth periodic oscillation.
In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation, used to transmit information, such as an audio signal, by radio waves.
Computer software, or simply software, is a generic term that refers to a collection of data or computer instructions that tell the computer how to work, in contrast to the physical hardware from which the system is built, that actually performs the work.
Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.
In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid.
A spacecraft is a vehicle or machine designed to fly in outer space.
A spark gap consists of an arrangement of two conducting electrodes separated by a gap usually filled with a gas such as air, designed to allow an electric spark to pass between the conductors.
A spark-gap transmitter is a device that generates radio frequency electromagnetic waves using a spark gap.
The power spectrum S_(f) of a time series x(t) describes the distribution of power into frequency components composing that signal.
A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument.
Speech synthesis is the artificial production of human speech.
Stereophonic sound or, more commonly, stereo, is a method of sound reproduction that creates an illusion of multi-directional audible perspective.
A superheterodyne receiver, often shortened to superhet, is a type of radio receiver that uses frequency mixing to convert a received signal to a fixed intermediate frequency (IF) which can be more conveniently processed than the original carrier frequency.
The Supreme Court of the United States (sometimes colloquially referred to by the acronym SCOTUS) is the highest federal court of the United States.
A surface acoustic wave (SAW) is an acoustic wave traveling along the surface of a material exhibiting elasticity, with an amplitude that typically decays exponentially with depth into the substrate.
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media.
The syphon or siphon recorder is an obsolete electromechanical device used as a receiver for submarine telegraph cables invented by William Thomson, 1st Baron Kelvin in 1867.
A table radio is a small, self-contained radio receiver used as an entertainment device.
Talk radio is a radio format containing discussion about topical issues and consisting entirely or almost entirely of original spoken word content rather than outside music.
Telecommunication is the transmission of signs, signals, messages, words, writings, images and sounds or information of any nature by wire, radio, optical or other electromagnetic systems.
In telecommunications a link is a communication channel that connects two or more devices.
A telegraph key is a switching device used primarily to send Morse code.
Telemetry is an automated communications process by which measurements and other data are collected at remote or inaccessible points and transmitted to receiving equipment for monitoring.
A telephone, or phone, is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be heard directly.
A telephone company, also known as a telco, telephone service provider, or telecommunications operator, is a kind of communications service provider (CSP) (more precisely a telecommunications service provider or TSP) that provides telecommunications services such as telephony and data communications access.
A telephone network is a telecommunications network used for telephone calls between two or more parties.
Television (TV) is a telecommunication medium used for transmitting moving images in monochrome (black and white), or in colour, and in two or three dimensions and sound.
A television antenna, or TV aerial, is an antenna specifically designed for the reception of over-the-air broadcast television signals, which are transmitted at frequencies from about 41 to 250 MHz in the VHF band, and 470 to 960 MHz in the UHF band in different countries.
A television channel is a broadcast frequency or virtual number over which a television station or television network is distributed.
Television receive-only (TVRO) is a term used chiefly in North America to refer to the reception of satellite television from FSS-type satellites, generally on C-band analog; free-to-air and unconnected to a commercial DBS provider.
A television set or television receiver, more commonly called a television, TV, TV set, or telly, is a device that combines a tuner, display, and loudspeakers for the purpose of viewing television.
A television station is a set of equipment managed by a business, organisation or other entity, such as an amateur television (ATV) operator, that transmits video content via radio waves directly from a transmitter on the earth's surface to a receiver on earth.
Terrestrial or broadcast television is a type of television broadcasting in which the television signal is transmitted by radio waves from the terrestrial (Earth based) transmitter of a television station to a TV receiver having an antenna.
A tetrode is a vacuum tube (called valve in British English) having four active electrodes.
Thermionic emission is the thermally induced flow of charge carriers from a surface or over a potential-energy barrier.
Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman, who has been described as America's greatest inventor.
A tikker, alternately spelled ticker, was a vibrating interrupter used in early wireless telegraphy radio receivers such as crystal radio receivers in order to receive continuous wave (CW) radiotelegraphy signals.
Tone control is a type of equalization used to make specific pitches or "frequencies" in an audio signal softer or louder.
A transceiver is a device comprising both a transmitter and a receiver that are combined and share common circuitry or a single housing.
A transducer is a device that converts energy from one form to another.
In engineering, a transfer function (also known as system function or network function) of an electronic or control system component is a mathematical function giving the corresponding output value for each possible value of the input to the device.
A variety of types of electrical transformer are made for different purposes.
A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power.
A transistor radio is a small portable radio receiver that uses transistor-based circuitry.
In electronics and telecommunications, a transmitter or radio transmitter is an electronic device which produces radio waves with an antenna.
A communications satellite's transponder is the series of interconnected units that form a communications channel between the receiving and the transmitting antennas.
A triode is an electronic amplifying vacuum tube (or valve in British English) consisting of three electrodes inside an evacuated glass envelope: a heated filament or cathode, a grid, and a plate (anode).
A tuned radio frequency receiver (or TRF receiver) is a type of radio receiver that is composed of one or more tuned radio frequency (RF) amplifier stages followed by a detector (demodulator) circuit to extract the audio signal and usually an audio frequency amplifier.
A tuner is a subsystem that receives radio frequency (RF) transmissions like radio broadcasts and converts the selected carrier frequency and its associated bandwidth into a fixed frequency that is suitable for further processing, usually because a lower frequency is used on the output.
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel).
A two-way radio is a radio that can do both transmit and receive a signal (a transceiver), unlike a broadcast receiver which only receives content.
Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one decimeter.
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without a human pilot aboard.
In electronics, a vacuum tube, an electron tube, or just a tube (North America), or valve (Britain and some other regions) is a device that controls electric current between electrodes in an evacuated container.
Valdemar Poulsen (23 November 1869 – 23 July 1942) was a Danish engineer who made significant contributions to early radio technology.
Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants.
Very high frequency (VHF) is the ITU designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten to one meter.
Very High Frequency (VHF) Omni-Directional Range (VOR) is a type of short-range radio navigation system for aircraft, enabling aircraft with a receiving unit to determine their position and stay on course by receiving radio signals transmitted by a network of fixed ground radio beacons.
Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media.
The volt (symbol: V) is the derived unit for electric potential, electric potential difference (voltage), and electromotive force.
Voltage, electric potential difference, electric pressure or electric tension (formally denoted or, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's circuit laws) is the difference in electric potential between two points.
A walkie-talkie (more formally known as a handheld transceiver, or HT) is a hand-held, portable, two-way radio transceiver.
The watt (symbol: W) is a unit of power.
Well logging, also known as borehole logging is the practice of making a detailed record (a well log) of the geologic formations penetrated by a borehole.
Western Electric Company (WE, WECo) was an American electrical engineering and manufacturing company that served as the primary supplier to AT&T from 1881 to 1996.
A whip antenna is an antenna consisting of a straight flexible wire or rod.
A wide area network (WAN) is a telecommunications network or computer network that extends over a large geographical distance/place.
Wildlife management attempts to balance the needs of wildlife with the needs of people using the best available science.
Sir William Crookes (17 June 1832 – 4 April 1919) was a British chemist and physicist who attended the Royal College of Chemistry in London, and worked on spectroscopy.
20018 In computer networking, a wireless access point (WAP), or more generally just access point (AP), is a networking hardware device that allows a Wi-Fi device to connect to a wired network.
A wireless local area network (WLAN) is a wireless computer network that links two or more devices using wireless communication within a limited area such as a home, school, computer laboratory, or office building.
A wireless microphone is a microphone without a physical cable connecting it directly to the sound recording or amplifying equipment with which it is associated.
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission, or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link.
Wireless telegraphy is the transmission of telegraphy signals from one point to another by means of an electromagnetic, electrostatic or magnetic field, or by electrical current through the earth or water.
World War I (often abbreviated as WWI or WW1), also known as the First World War, the Great War, or the War to End All Wars, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918.
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