Simulation of radiated coupling effects in communication payload transponders

Coherent radiated emissions onboard spacecrafts can get coupled to the sensitive subsystems like receivers, pre-amplifier and high gain solid state amplifier, demux filters etc. and cause severe degradation in the frequency response in the transponder channels and make them unfit for use or limit their optimum utilization. A single channel transponder was simulated in lab and the level of degradation in frequency response due to coherent radiated coupling from output section to input section at different field strengths was measured. The data is very useful in generating an effective onboard EM compliance plan for communication satellite payloads.