High gain compact ultra‐wideband “antenna‐frequency selective surface” and its performance evaluation in proximity of soil surface

Abstract

AbstractHigh gain compact ultra‐wideband (UWB) antenna is essential for various UWB applications including impulse radar. U‐shaped UWB antenna is developed from the usual square shaped patch and cascaded with simply designed aperture like uniplanar frequency selective surface (FSS) that has 4 × 4 array of square slots inside metal patch in its unit cell. Compact unit cell of dimension 11 × 11 mm2 realizes bandwidth from 0.001 to 15.8 GHz. The compact UWB “antenna‐FSS” provides gain augmentation of 2.5 to 5.2 dBi in the 2.94 to 15.26 GHz (135%) band with highest gain augmentation of 5.2 dBi at 8.94 GHz. The “antenna‐FSS” offers stable omnidirectional radiation patterns and measured radiation efficiency variation from 76% to 84% in its bandwidth. Transient and frequency responses of this unique compact high gain UWB “antenna‐FSS” structure is also analyzed in environs of sandy soil. Linear transfer function (S21) and non‐varying group delay responses in the unaffected impedance band of “antenna‐FSS” ensure its non‐dispersive nature while used for ground penetrating radar application.