Circularly Polarized UWB Antenna with Question Mark Shaped Patch for GPR Applications

Abstract

A novel Circularly Polarized (CP) Ultra Wideband (UWB) antenna for Ground Penetrating Radar (GPR) applications is presented and discussed in this paper. The proposed antenna is constructed by a question mark shaped radiating patch and a truncated ground plane. A prototype of the designed antenna is fabricated on the FR4-substrate with an overall volume of 0.7?0×0.793?0×0.035?0 at 7 GHz. The simulated results show that the designed antenna has an Impedance Bandwidth (IBW) ranging from 3.14 GHz to 11.88 GHz (116.38%). The CP feature is analyzed and discussed confirming that the antenna maintains a CP radiation characteristic in a broadband with a 3-dB Axial Ratio Bandwidth (ARBW) ranging from 4.13 GHz to 9.28 GHz (76.81%). The measurements were done by utilizing a well calibrated R&S®ZNB Vector Network Analyzer indicating that the fabricated prototype has an IBW nearly ranging from 3.47 GHz to 12.11GHz (110.91%). The results are favorable that ensure the usefulness of this antenna for GPR applications.