A Square Microstrip Patch Antenna with Enhanced Return Loss Through Defected Ground Plane for 5G Wireless Networks

In this paper, we design an inset fed square microstrip patch antenna with defected ground plane for 15 GHz which is one of the projected 5G frequency bands. The first design concept is a conventional inset fed square microstrip patch antenna which has a return loss level of -35.339 dB and a bandwidth of 1.04 GHz at 15 GHz. For lower return loss level and higher bandwidth requirements the proposed antenna is modified by etching diamond-shaped slots on the radiating patch. The coordinates of the etched slots are determined using parametric analysis to meet the objectives of large impedance bandwidth and low return loss in the desired frequency. For this second prototype, we observe a bandwidth of 1.08 GHz and a return loss of -53.147 dB. To obtain the effects of defected ground on the characteristics we etch a diamond - shaped defect on the ground plane with an area of 0.005 mm
²
. This defect results in additional return loss with 9.81 dB at the same frequency with the same bandwidth. As a result the proposed antenna provides an increment of 40 MHz in the bandwidth and a decrement of 27.618 dB in return loss level at the resonant frequency. Due to these novel characteristics, the proposed antenna can be a good candidate for 5G wireless networks as a transmitter or receiver where bandwidth and high impedance matching for maximum power transfer is an important issue.