Development of Active Radar Calibrator for L-,C-,X-, and Ka-band SAR

During the past decade, IECAS (Institute of Electronics, Chinese Academy of Sciences) has developed a set of L-, S-, C- and X-band active radar calibrators deployed during the calibration campaigns for HJ1C SAR,Gaofen-3 SAR and so on. In the near future, P-band and Ka-band spaceborne SARs will be launched. We find it is a waste to develop the special ARCs for a specific SAR or a specific frequency band SAR and the acquired experience can help us to design and develop a multiband active radar calibrator (ARC). This paper describes the design and implementation of a novel multiband active radar calibrator which can operate at L-, C-, X- and Ka-band, and manufacture process is introduced. Also laboratory measurements were performed to characterize the performance of the multiband ARC, especially gain stability, system transfer function, gain flatness and linearity of ARC receiver were paid specific attention to. Three such ARCs were developed and they will be the first multiband ARC in China or even in the world, and it can be used to implement the calibration campaigns of Chinese Gaofen-3 SAR, Shenzhen-1 SAR, Luojia-2 SAR and so on. The results obtained from the measurements show that the performance of the multiband ARC is rather satisfactory.