Dual-band FSS design using LC traps

This paper introduces resonant “traps” and their potential uses to frequency selective surfaces (FSS). A trap can be considered a passive frequency selective switch offering a high or low impedance state depending upon operating frequency. The paper illustrates an established trap application and introduces the potential for use in FSS designs. A harmonically or near harmonically related dual-band annular ring application is discussed, with the design being realised both by simulation and measurement, the results of which are presented and evaluated.