Investigation into Air Loaded Shorted Microstrip Antenna with Hanging Post Integrated Patch Surface to Improve Impedance Matching and Reduce Cross Polarization Radiation

In this paper, authors have investigated a simple, low profile, probe fed, shorted rectangular microstrip patch antenna with air gap inserted between substrate (with relative permittivity of ε
_r
= 4.4) and ground plane for improved impedance matching , and CP-XP isolation in both H and E planes. In each corner of the patch, a hanging post or pin has been put. It has been observed that both the shorting post and the hanging posts have a strong influence on improving impedance matching and reducing cross-polar radiations from the antenna. Around 21 dB peak CP-XP isolation is achieved in H plane. The H-plane and E-plane beam-widths of the proposed antenna are 72° and 83°.