Circuit of Encryption Wireless TV

Published:2011/4/20 7:52:00 Author:TaoXi | Keyword: Encryption, Wireless, TV | From:SeekIC

The circuit of encryption wireless TV with 1W transmit power is as shown. The input signal are audio and video signals, and the launch channel is decided by the SW SAW resonator in modulation circuit. Video signal that sent by the cameras, video recorders, VCD and other equipment will transport into the 3-pin of the encryption module of the transmitter, then output the encrypted video signal, and modulated in to the RF signals by modulation circuit, VT1, VT2 voltage amplification, VT3 promote amplification, VT4 power amplifier, at last launch out by the antenna. Because of the VTl ～ VT4 is amplified by broadband (46～870MHz), so between the power amplifier and antenna band-pass filter need to use the bandpass filter to prevent the band emissions. The decryption receiver is composed of TDQ-3 tuner, finished TA7680 board and the decryption module, as shown in the figure. Receiver receives the transmitted signal, converses the frequency in high-frequency tuner, and outputs the 38MHz IF signal, outputs audio signal and the encrypted video signal, and after decrypted by the decryption module 8910, we get the video signal to watch.



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