AMC-based high-isolation SIW slot array antennas for ka-band SAR systems

In this paper, an artificial magnetic conductor (AMC) structure is utilized to suppress the mutual coupling between two 20×20 slotted substrate-integrated waveguide (SIW) array antennas for Ka-band synthetic aperture radar (SAR) systems. The study of decoupling mechanism suggests that with the in-phase reflection characteristic of an AMC structure, the phase of the coupling space wave can be manipulated for the decoupling between SIW slots. The performance results of two Ka-band array antennas show that the achieved in-band isolation using the proposed AMC reaches up to 15dB and 11dB higher than that using a double-layered metal wall in simulation and measurement, respectively. The antennas are designed and successfully applied to the self-developed indoor SAR testing system.