An Efficient Technique for Wide Band RCS Reduction of Patch Antenna Array Using Rectangular Cavity Walls and Phase Cancellation Principle

The rectangular cavity is investigated and applied in the field of the radar cross section reduction (RCSR) of patch antennas for the first time. An integrated and efficient design technique is presented which uses both a slotted rectangular cavity and reflective phase cancellation by a simple artificial magnetic conductor (AMC) element. On condition that ensuring the radiation performance of the patch antenna does not deteriorate, the in-band radar cross section (RCS) of the antenna can be reduced by 12.2 dB at 7.6GHz just relying on a type of phase-regulated AMC elements. On this basis, the rectangular cavity walls were first loaded surrounding the above-mentioned low-RCS patch antenna. The relative bandwidth (in which RCS was reduced by more than 8 dB) went from 3.33% to 50% in the RCSR of the antenna. Meanwhile, the RCS could be reduced by an additional 5 dB at its working frequency (7.6 GHz).