Fill Light,Ring Light,Led Ring Light,Selfie Ring Light Shaoxing Shangyu Kenuo Photographic Equipment Factory , https://www.kernelphoto.com The principle of the receiver is to amplify the RF signal from the antenna with a low noise amplifier (LNA) and downconvert the RF signal before demodulation. The direct wave from the upper and lower antennas and the wave arriving at the receiving point through various paths (multipath propagation) pass through two identical channels: bandpass filter, low noise amplifier, mirror filter, and reception The frequency converter, the pre-amplifier, and then the synthesis, and then output the intermediate frequency modulated signal after the main intermediate frequency amplifier.