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Encrypted Wireless Video and Audio Transmitter circuit

Published on Dec 23 2010 // Telephone Communication Circuits

Encrypted Wireless Video and Audio Transmitter circuit 1

Encrypted Wireless Video and Audio Transmitter circuit  2

The figure shows the transmitter power of 1W encrypted television transmitter circuit. The input signal is audio and video signals, transmitting channel in the SW by the modulation circuit SAW resonator decision. By the camera, VCR, VCD and other equipment sent encrypted video signal into the transmitter module ? feet, encryption after the encrypted video signal output pin ?, the TA7673 composed of modulated RF signal modulation circuit after the VT1, VT2 voltage amplification, VT3 promote amplification, VT4 power amplifier, from antenna out. As VTl ~ VT4 amplified by broadband, the bandwidth of 46 ~ 870MHz, so between the power amplifier and the antenna band-pass filter should be used to prevent the emission band, the impedance matching.
Decrypted by the TDQ-3 receiver tuner, put plate in the finished product TA7680, decryption modules, as shown below. Receiver receives the transmitted signal, in the high-frequency output after the first frequency within the 38MHz IF signal, demodulated output audio signal and the encrypted video signals, and then after decryption module 8910 are watching surveillance video signal.