Patent ID: 11894942
Assignee: NANNING FULIAN FUGUI PRECISION INDUSTRIAL CO., LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 4:
5. The communication system based on DOCSIS protocol according to claim 4, wherein the tertiary filter path comprises:
the second low-pass filter, the input end of the second low-pass filter being electrically connected to the frequency divider, and configured for passing the downstream signal with a bandwidth of 108 MHz˜684 MHz;
the first synthesizer, the first input of the first synthesizer being electrically connected to the output end of the second low-pass filter;
the first RF switch, the common end of the first RF switch being electrically connected to the output end of the first synthesizer;
the third low-pass filter, the input end of the third low-pass filter being electrically connected to the second end of the first RF switch, the third low-pass filter being configured for passing the downstream signal with a bandwidth of 108 MHz˜492 MHz;
the second synthesizer, the first input end of the second synthesizer being electrically connected to the output end of the third low-pass filter;
the second RF switch, the common end of the second RF switch being electrically connected to the output end of the second synthesizer;
a fourth low-pass filter, an input end of the fourth low-pass filter being electrically connected to a second end of the second RF switch;
a third synthesizer, a first input end of the third synthesizer being electrically connected to an output end of the fourth low-pass filter, an output of the third synthesizer being electrically connected to the first modulation and demodulation unit, the third synthesizer being configure for transmitting the downstream signal with the bandwidth of 108 MHz˜300 MHz to the first modulation and demodulation unit;
a third phase regulator, an input end of the third phase regulator being electrically connected to the second modulation and demodulation unit, the third phase regulator being configured for phase adjustment of the upstream signal sent by the second modulation and demodulation unit;
a fourth power amplifier, an input end of the fourth power amplifier being electrically connected to an output end of the third phase regulator, and the output end of the fourth power amplifier being electrically connected to the second input end of the third synthesizer, the fourth power amplifier being configured for adjusting a power of the phase adjusted signal and output a signal with an opposite phase and a same power as the upstream signal sent by the second modulation and demodulation unit;
the system-on-a-chip, electrically connected to the fourth power amplifier, and configured for controlling a magnification of the fourth power amplifier.