C-band solid state dual polarization T/R modules for airborne SAR applications

The use of distributed power in a phased array antenna based SAR system offers new possibilities for the system operation. As a preparation for future spaceborne SAR systems using solid state transmitters with electronically steerable phased array antennas, the PHARUS system is under construction. The system will be installed on a Metro II or a Cessna Citation II aircraft. The system will have a number of user selectable modes for polarizations (one to fully polarimetric), resolution (4 meter/4 looks to 16 meter/20 looks), altitude (5 km to 12 km), swath width (4.4 km, high resolution, polarimetric until 20 km, low resolution, one polarization) and incidence angle range. The different features within a mode are more or less coupled due to signal to noise limitations and maximum data rate. The radar is set up in such a way that extensions in a later stage are possible. For example a larger bandwidth or the enlargement of the antenna including the number of T/R modules. This paper describes the dual polarization T/R module design, including the module characterization for calibration purposes, as well as designs for the module monitoring and power supply