Onboard passive return signal simulator for space-borne radar altimeters

It is important for a spaceborne radar altimeter to have the ability for onboard waveform calibration. However it is difficult to simulate the return wave at microwave frequency that contains a complete waveform. In this paper, we present a novel design for a passive return signal simulator (RSS) which has the ability to provide a complete waveform using a signal calibration measurement. This passive RSS is compact, therefore it can be used for both onboard and ground calibrations