Wideband Filtering Antenna Fed through Hybrid Substrate Integrated Waveguide and Spoof Localized Surface Plasmon Structure

In this communication, we propose a novel feeding scheme to design a wideband filtering patch antenna. The antenna is composed of two substrates: the feeding- and the radiating ones. Two circular patches are etched on the top surface of the radiating substrate as the radiators and a hybrid substrate integrated waveguide (SIW) and spoof localized surface plasmon (SLSP) structure is employed as the feeding scheme. Due to the abundant resonant modes and filtering feature of the hybrid SIW-SLSP structure, the antenna can radiate under the triple-mode resonance with high filtering performance. Moreover, the proposed filtering antenna has an independently adjustable capability of both low-band and high-band radiation nulls. The presented antenna is designed, fabricated and measured. Measured results reveal that the operating bandwidth reaches up to 11.3%, ranging from 7.44 GHz to 8.33 GHz. The peak gain of 10 dBi is obtained in passband with 10 dB gain suppression out of the band. This approach provides a simple way to design wideband filtering patch antenna, which can be easily integrated with planar circuit.