Microwave frequency modulation device for transferring or receiving video and audio signals

Microwave frequency modulation device for transferring or receiving video and audio signals

  • CN 2,267,535 Y
  • Filed: 09/12/1995
  • Issued: 11/12/1997
  • Est. Priority Date: 09/12/1995
  • Status: Active Grant
First Claim
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1. , the audio-visual transmission receiving system of a kind of microwave frequency modulation, include radiating circuit and receiving circuit, it is characterized in that:

  • wherein radiating circuit is so to constitute;

    the picture intelligence by the input of picture intelligence input inserts the input that this signal is carried out the image processing circuit of pre-emphasis and amplification earlier, sound left and right sound track signals by the input of voice signal input also inserts the sound treatment circuit that its signal is carried out pre-emphasis earlier, and is tuned at paying on the carrier wave of 6MHZ and 6.5MHZ with mode of frequency regulation respectively;

    Insert behind the signal plus of image processing circuit and sound treatment circuit it is carried out the tuning vibration/tuner of frequency modulation, afterwards, order inserts the power amplifier that signal is amplified, first filter and the transmitting antenna of filtering harmonic wave again;

    Wherein receiving circuit is so to constitute;

    its reception antenna links to each other with the input of low-noise amplifier, this low-noise amplifier output is connected to can be with neighbour'"'"'s frequency target signal filter, and the compensation surface acoustic wave causes the input of second filter of the loss of signal, the output of second filter is connected to the input that uses phase-locked loop (PLL mode) to produce the frequency mixer of local oscillated signal, it is a fixed bit standard that the output access of this frequency mixer can be adjusted input signal strength, can not make the signal that enters demodulator too strong and cause the input of the variable gain amplifier of distorted signals after the demodulation, the output of this variable gain amplifier then is connected to the output of the 3rd filter, the output of the 3rd filter is connected to amplifier input terminal, the output of this amplifier is connected to the input of demodulator, the output of demodulator is connected to the input of image processing circuit sound treatment circuit, image processing circuit and sound treatment circuit output are connected on the external circuit, be connected to the input of variable gain amplifier again with another output of demodulator, and oscillator output end is connected on another output of frequency mixer, to receive the signal of radiating circuit emission.

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