A Wheel Shaped Compact UWB Antenna for GPR Applications

For ground penetrating radar applications, a new compact planar ultra wideband (UWB) antenna is presented. It consists of CPW feed and a radiating patch. The CPW feed is connected to the patch using stepped impedance which has been filleted. An inner ring and an outer ring, connected by two orthogonal strips for bandwidth enhancement, make up the wheel-shaped radiating patch. The frequency range of the test antenna is 3.01 to 19.88 GHz, making it an ultra-wideband antenna. The overall size of the antenna is 29×18×1.6 mm
³
on the FR-4 substrate. The Full Width Half Maxima (FWHM) bandwidth is greater than 17.56 GHz ranging from 2.44 GHz to greater than 20 GHz. Three resonance peaks are obtained at 3.51, 7.76 and 18.77 GHz with return loss value of -25.38, -40.88 and -30.67 dB respectively. The antenna is characterized for ground coupling test. According to simulation performance, the proposed antenna has a 147% percentage bandwidth, gain ranging from 2 to 6 dB, and efficiency ranging from 70% to 95%. The results show that the proposed design can be used as a GPR antenna.