As we all know, the C-band downlink receiving link (3.4-4.2GHz) of satellite communication overlaps with the 3.5GHz (3.4-3.6GHz) frequency band of 5G mobile communication. In order to avoid spectrum conflict, the starting frequency of C-band of satellite communication is moved up to 3.7GHz (Some sites are 3.625GHz or 3.8GHz), even so, because the spectrum is too close, the C-band receiving link cannot avoid interference from the 5G mobile communication transmitter.

At present, there are roughly two methods for solving the interference problem of the satellite C-band receiving link as follows:

1. Waveguide filter

Add a waveguide filter at the antenna feed end, the main indicators of the waveguide filter are as follows:

Passband frequency: 3.7-4.2GHz 3.625-4.2GHz 3.8-4.2GHz

It can be seen that the waveguide filter can effectively filter out the interference signal from 5G.

2. Anti-5G interference low noise amplifier (LNA or LNB)

Anti-5G interference low-noise amplifiers can effectively filter out interference signals from 5G on the premise of ensuring that the system noise temperature does not deteriorate. Currently, there are two main solutions for anti-5G interference low-noise amplifiers on the market: 1. Built-in cavity filter , 2, Embedded microstrip filter.