Microstrip Antenna with A New Kind of External Loading for Improved Backside Radiation and Enhanced Polarization Purity

Two coax-fed stub loaded microstrip antennas have been designed and studied here. The idea has been evolved in need of developing a planar improved polarization purity and low backside radiation patch compared to a non-planar configuration published in a recent article by the same author. The proposed structures show 10dB enhanced co-to-cross isolation. One of them shows low backside radiation. An X-band prototype has been fabricated and examined using an in-house measurement facility. 15dB isolation has been achieved in the H-plane following 25dB in the E-plane. Also, a trace of suppressing backside radiation has been identified.