Analysis of Effect of Telecommand Signal on Downlink Signal in Deep Space Exploration
Xueying Wu · Spacecraft Engineering · 2013
The approach by with the uplink residual telecommand signal affects the downlink signal is discussed,and the effect of the uplink telecommand signal on reference signal of downlink carrier from the output of VCXO in the phase lock loop is mainly analyzed.This influence is not prominent in low-orbit spacecraft,but in some deep space exploration missions,it deserves more attention.At the same time,an improvement method is came up with aiming at the influence,and a simulation analysis has been carried on.In practice,by adding a band-pass filter to the output of VCXO in the phase lock loop,the residual telecommand signal in the downlink can be further inhibited by about 20dB,making the downlink carrier signal achieve the relevant specification requirements.