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A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the ...
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 ...
English: Block diagram of a tuned radio frequency (TRF) receiver, a type of radio receiver circuit invented in 1916 by Ernst Alexanderson and widely used in the vacuum tube receivers of the 1920s.
Here we show block diagrams for typical superheterodyne receivers for AM and FM broadcast respectively. This particular FM design uses a modern phase locked loop detector, unlike the frequency discriminator or ratio detector used in earlier FM receivers. A schematic of a simple superhet broadcast FM receiver.
At the end of each data frame, the receiver stops briefly to wait for the next start bit. It is this difference that keeps the transmitter and receiver synchronized. BCLK = Base Clock. A UART frame consists of 5 elements: Idle (logic high (1)) Start bit (logic low (0)): the start bit signals to the receiver that a new character is coming.
Cross-section across a low-noise block downconverter. Viewing of the pin and the horn antenna in a low-noise block downconverter. The LNB gets its power from the receiver or set-top box, using the same coaxial cable that carries signals from the LNB to the receiver. This phantom power travels to the LNB; opposite to the signals from the LNB.
If four transmitters are coupled to one antenna, a quarter of each transmitter's power will reach the output of the combining circuit. Part of this loss can be made up with increased antenna gain. Fifty watts of transmitter power to the antenna will make a received signal strength at a distant mobile radio that is almost identical to 100 watts.
Many smaller BUCs also get their direct current (DC) over the feedline, using an internal DC block. BUCs are generally used in conjunction with low-noise block converters (LNB). The BUC, being an up-converting device, makes up the "transmit" side of the system, while the LNB is the down-converting device and makes up the "receive" side.