Dual Transmission Miniaturized A-T-A-T FSR

In the preceding chapter, an A-T-A-type FSR incorporating an MF resonator was introduced to enhance passband selectivity. Despite this, applications involving dual-band radiating systems particularly for RCS reduction and EMI mitigation necessitate the development of FSRs with dual transmission features. Given the growing adoption of dual-/multiband antennas in modern communication systems, the design of such rasorbers has become increasingly important. This chapter presents a systematic approach to developing a compact A-T-A-T FSR offering dual transmission bands along with strong angular stability. The design methodology involves strategic use of low-frequency resonators on the resistive layer to support size reduction and a detailed investigation of cross-loop resonators to generate two distinct transmission poles through the lossy layer.