A High-Efficiency Resonant Frequency Tuning Method for AFSR Based on Multiple Resonant Modes

This paper presents a method for tuning the resonant frequency of an absorptive frequency selective reflection (AFSR) structure based on multiple resonant modes. The AFSR structure enables the absorption-reflection-absorption characteristics realized by the bent metallic strip embedded with chip resistors. On this basis, the metallic strip's electric field distribution at different frequencies is analyzed to find the suitable position for loading stubs. Then, the regulation of different resonant frequencies is achieved by changing the length of the stubs.