Multibeam scanning front-end for SAR

Over the last decades, the spaceborne remote sensing community has been focused on the development of imaging radars at RF frequencies such as S-band, L-band, C-band and X-band.
ITU regulations currently permit the use of Ka-band for active spaceborne microwave remote sensing but only few missions are considering applying this frequency band such as the SARAL mission with the ALtiKa instrument (launched 2013).
Studies have been performed which demonstrate the Ka-band is an attractive frequency for imaging missions especially for the realisation of compact interferometric instruments which can be used to 

provide accurate digital surface models as well as high-resolution maps of areas of interest.
Advanced SAR imaging techniques such as scan-on-receive (SCORE), which use a wide transmit beam but high-gain pencil beams on receive can be applied to achieve reasonable imaging performance at Ka-band in terms of swath width and sensitivity. The use of SCORE in a reflector-feed-array configuration is an attractive solution to limit the number of array elements needed as well as providing a very good ambiguity rejection.
In this context, a new activity with TDE and OHB Systems, Germany) has developed and tested the implementation of a Ka-band SCORE breadboard front-end for SAR to investigate the feasibility of 

Ka-band SAR and act as a technology roadmap for these kind of instruments.
The activity aimed to demonstrate mixed analogue/ digital beam-forming electronics for a reflector-based scan-on-receive (SCORE) front end.
The KaSCORE breadboard has been successfully implemented and tested, demonstrating for Ka-band SAR applications that the anticipated front-end design and underlying concept is feasible.
Several key aspects have been successfully demonstrated by the breadboard, such as fast-time domain beamforming, real-time digital beamforming of signals up to 500 MHz RF. The breadboard also used the latest generation of digital hardware for spaceborne applications, i.e. the Texas Instruments ADC12DJ3200 and the Xilinx KU060 FPGA.
T106-506ET closed in 2021