Search results
Results from the WOW.Com Content Network
Block diagram of a superheterodyne receiver. The RF front end consists of the components on the left colored red. In a radio receiver circuit, the RF front end, short for radio frequency front end, is a generic term for all the circuitry between a receiver's antenna input up to and including the mixer stage. [1]
English: Block diagram of a tuned radio frequency (TRF) receiver, the simplest type of amplifying radio receiver circuit. It consists of one or more tuned RF amplifiers, each consisting of a tuned circuit which functioned as a bandpass filter followed by a radio frequency (RF) amplifier; a detector (demodulator) to extract the audio waveform from the radio carrier wave; followed by an audio ...
It consisted of one or more tuned RF amplifiers, each consisting of a tuned circuit which functioned as a bandpass filter followed by an amplifier; a detector (demodulator) to extract the audio waveform from the radio carrier wave; followed by an audio amplifier.
The RF signal from the antenna may have one stage of amplification to improve the receiver's noise figure, although at lower frequencies this is typically omitted. The RF signal enters a mixer, along with the output of the local oscillator, in order to produce a so-called intermediate frequency (IF) signal. An early optimization of the ...
English: Block diagram of a single conversion superheterodyne radio receiver. Invented by Edwin Armstrong in 1918 during World War 1, the superheterodyne is the design used in almost all modern radio receivers.
A variable capacitor (or sometimes a variable coupling coil called a variometer) was used, with a knob on the front panel to tune the receiver. The RF stages usually had identical circuits to simplify design. Each RF stage had to be tuned to the same frequency, so the capacitors had to be tuned in tandem when bringing in a new station.
English: Block diagram of a simple reflex radio receiver, an unusual type of radio receiver invented by Marius Latour and William Preiss in 1917 that was used to a limited extent in the 1920s. The distinguishing feature of the reflex circuit is that the amplifier is used to amplify both the radio frequency (RF) and audio frequency (AF) signals ...
A basic SDR system may consist of a computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio ...