EM compliance of narrow band input mux filters by using EMI screened components

Electromagnetic compliance in communication satellite payloads is a very essential element for satisfactory performance of the onboard transponders. Input MUX filters (Demultiplexers) are sensitive components of the payload. A filter assembly may employ 6 to 12 channel individual narrow band passive filters with each filter incorporating an input circulator and an output isolator for separating the various transponder channels and providing good output return loss matching. The narrow band filters should have high immunity against high coherent field emissions from the down link power transmit section components like TWTAs, Muxes, Wave guide plumbing joints etc. Coupling of these leakages at the input or directly at the output of the filters should be well below the corresponding channel carriers to avoid degradation in frequency response of the transponders.