Design of mechanically reconfigurable frequency selective surface with second-order bandpass frequency response

Abstract In this paper, a Mechanically Reconfigurable Frequency Selective Surface (MRFSS) with second-order bandpass frequency response is proposed, and a mechanically tuned servo control system is designed for the MRFSS. Passband of the proposed MRFSS can be tuned by adjusting the depth of the male mode of the MRFSS’s dielectric layers inserted into the slots of the metal layers. Influence laws of insertion depth on the resonant frequency, passband bandwidth, and insertion loss are investigated via full-wave simulations. The mechanism of mechanical tuning is analyzed using an equivalent circuit model (ECM). The correlation mapping model between the insertion depth and the capacitance value of the adjustable capacitor in the equivalent circuit is established by curve fitting, which facilitates the subsequent determination of the control variables. The simulation results show that the MRFSS has a tuning range of 2.78 to 3.90 GHz. For further verification, a prototype of the proposed MRFSS is fabricated and the MRFSS prototype is motivated by the servo control system for measurement. Good agreements between the simulated and the measured results can be observed.