A Printed U-Shaped Coplanar Waveguide Fed UWB Antenna for GPR Applications

A printed U-shaped coplanar waveguide fed (CPW) ultra-wideband (UWB) antenna is designed, fabricated, and measured in this paper for ground penetrating (GPR) applications. Some cutoffs were introduced into different parts of the antenna to improve the working bandwidth. The antenna was printed on the FR4-epoxy substrate in a compact size of 0.259λ0×0.309λ0×0.015λ0 at 3 GHz. The calculated results were validated by realizing and measuring a prototype. Experimental demonstrations were done using the R&S®ZNB Vector Network Analyzer, which indicates that the working bandwidth extends from 3.09 GHz to 11.07 GHz (112.71%). Additionally, the radiation patterns of the antenna were measured in an isolated anechoic chamber, which shows that the proposed antenna has omnidirectional radiation patterns. Moreover, acceptable antenna gain values ranging between 1.74 and 7.04 dBi and high values of radiation efficiency of more than 80% were achieved over the whole working bandwidth. Besides, the antenna presents a stable group delay with a linear phase of S21 through the UWB frequency band. To prove the efficiency of the fabricated antenna for GPR applications, the operation of the antenna was experimentally tested in a sandy soil box. The obtained results show that the proposed antenna could be a good candidate for GPR applications. © 2022, Advanced Electromagnetics. All rights reserved.