A Circularly Polarized T-Shaped Patch Antenna for Wireless Communication Application

The present study is related to a Dual-band circularly-polarized (CP) microstrip patch antenna consisting of a single T-shaped radiating patch which consists of a square loop slot on the opposite side of the substrate, and two slotted stubs placed across the diagonal line of the square loop. This configuration is considered for axial ratio bandwidth (ARBW) enhancement. In order to increase the impedance bandwidth (IBW) by a significant amount, the proper dimension of T-shaped has been used. The structure leads to three notches (at <−10 dB) of the bandwidths of 1.32 GHz (8.48-9.78 GHz), 0.71 GHz (10.99–11.7 GHz), and 5.43 GHz (12.21–17.64 GHz) with the corresponding simulated center frequencies of 9.1 GHz, 11.3 GHz, 15.9 GHz respectively. The measured IBW below −10 dB are 7.54-7.98 GHz, 8.74-9.557 GHz, 12.42-14.97 GHz, 16.16 GHz – beyond 20 GHz (as beyond 20 GHz the IBW cannot be measured using our specified VNA). The ARBW are 301 MHz $(\mathbf{f}_{\mathbf{c}}=9.5\ \mathbf{GRz}, 3.17\ \%)$ I and 462 MHz $(\mathbf{f}_{\mathbf{c}}=13.1\ \mathbf{GRz},\ 3.53\%)$ within the range of simulated and measured impedance bandwidth curve. The maximum simulated peak gain is 2.02 dBi at 11.3 GHz. Proposed antenna happens to be suitable for ‘X’ and ‘K’ band wireless communication application.