Wideband Circular Polarized SIW Antenna for Millimeter Wave

A circularly polarized (CP) microstrip antenna having two anti-symmetric arms has been suggested in this paper. It primarily comprises of two anti-symmetric arms as a patches that are excited by one microstrip line and coupled to a microstrip cavity through another microstrip line. Circular polarization is caused by the fact that both of a microstrip’s anti-symmetric arms emit radiation of nearly equal magnitudes and at a 90° phase difference. On the ground plane, there are two triangular parts and a patch-shaped slot. Circular polarization has been achieved in the suggested antenna throughout a broad frequency range, and the impedance bandwidth of the design antenna is also substantial. The suggested antenna’s shows 3-dB axial ratio in 2.2 GHz band (28.2–30.4 GHz), its axial ratio beamwidth is 60°, and its percentage impedance bandwidth is 23% from 26.5 GHz to 31.7 GHz at central frequency 28 GHz. The high gain of the planned antenna, 10.8 dB at resonance frequency, is achieved by the SIW resonator, which is positioned between the radiating patch and feed. Having a simple structure, easy to fabricate and low manufacturing costs, this antenna offers the best CP performance of any single feed microstrip patch antenna. © 2023, The Institution of Engineers (India).