Flexible Liquid-Metal-Tuned Higher-Order Bandpass Frequency Selective Surfaces

This paper presents a new implementation of liquid-metal-tuned higher-order bandpass frequency selective surfaces (FSSs). The proposed multi-layer periodic structures are based upon a topology consisting of resonant FSS layers separated by thickness-controlling aperture coupling interlayers. These liquid metal layers are used in combination with an elastomeric substrate to realize a mechanically flexible and fluidically tunable device. Capacitive tuning slugs are integrated into the resonant FSS layers to enable real-time tuning of the bandpass filter's operating frequency range. To demonstrate the proposed higher-order liquid-metal-tuned spatial filters, both second-order and third-order bandpass FSSs, operating in the Ku-band, are designed and validated using full-wave electromagnetic simulation.