A Small-Aperture and High-Performance Endfire Holographic Antenna Based on Spoof Surface Plasmon Polaritons

In this letter, a spoof surface plasmon polariton (SSPP) antenna with endfire radiation is inspired by the holographic technique. In contrast to the previous studies with optimization-based structures or using SSPP odd modes, we propose a simple method to design an endfire SSPP antenna based on the holographic principle that can maintain the stability of the endfire radiation over 23% of the impedance bandwidth. The proposed method includes twice modulating the structure with a 180° phase difference. This method eliminates the null in the endfire radiation pattern created by the conventional sinusoidally modulated reactance surface technique. The proposed SSPP holographic antenna presents a stable endfire radiation pattern within the frequency range of (8 to 10) GHz. The realized gain and radiation efficiency at the design frequency of 9 GHz are 13.1 dBi and 95%, respectively. An antenna prototype is fabricated and measured in the anechoic chamber. The full-wave simulation results of the CST software agree well with measured ones. This miniaturized endfire SSPP holographic antenna can be a potential candidate for wireless communication applications and integrated circuits.