Radio technology

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.

Radio control (often abbreviated to R/C or simply RC) is the use of radio signals to remotely control a device.

Yttrium iron garnet spheres (YIG spheres) serve as magnetically tunable filters and resonators for microwave frequencies.

A resonance chamber uses resonance to amplify sound.

An electronic oscillator is an electronic circuit that produces a periodic, oscillating electronic signal, often a sine wave or a square wave.

A microphone, colloquially nicknamed mic or mike (/ˈmaɪk/), is a transducer that converts sound into an electrical signal.

Microwaves are a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter; with frequencies between 300 MHz (100 cm) and 300 GHz (0.1 cm).

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

An operational amplifier (often op-amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output.

Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light.

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power.

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 spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument.

Electronic filters are circuits which perform signal processing functions, specifically to remove unwanted frequency components from the signal, to enhance wanted ones, or both.

The Family Radio Service (FRS) is an improved walkie-talkie radio system authorized in the United States since 1996.

A corner reflector is a retroreflector consisting of three mutually perpendicular, intersecting flat surfaces, which reflects waves back directly towards the source, but translated.

Ferrite circulators are radio frequency circulators which are composed of magnetised ferrite materials.

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.

An audio power amplifier (or power amp) is an electronic amplifier that amplifies low-power electronic audio signals (signals composed primarily of frequencies between 20 - 20 000 Hz, the human range of hearing) to a level that is strong enough for driving loudspeakers and making the signal–whether it is recorded music or a live speech–audible to listeners.

In telecommunications, squelch is a circuit function that acts to suppress the audio (or video) output of a receiver in the absence of a sufficiently strong desired input signal.

Tube sound (or valve sound) is the characteristic sound associated with a vacuum tube-based audio amplifier.

TV radio, TV band radio, and TV audio radio are common names for a type of radio receiver that can play the audio portion of a TV channel.

C-RAN (Cloud-RAN), sometimes referred to as Centralized-RAN, is a proposed architecture for future cellular networks.

Radio frequency (RF) is any of the electromagnetic wave frequencies that lie in the range extending from around 3 kHz to 300 GHz, which include those frequencies used for communications or radar signals.

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.

Selcall (selective calling) is a type of squelch protocol used in radio communications systems, in which transmissions include a brief burst of sequential audio tones.

Datacasting (data broadcasting) is the broadcasting of data over a wide area via radio waves.

A personal radio service is any system that allows individual to operate radio transmitters and receivers for personal purposes with minimal or no special license or individual authorization.

In a conventional, analog two-way radio system, a standard radio has noise squelch or carrier squelch which allows a radio to receive all transmissions.