A Physical Insight Into the Influence of Dominant Mode of Rectangular Microstrip Antenna on Its Cross-Polarization Characteristics and Its Improvement With T-Shaped Microstrip Antenna

In this paper, the cross polar radiation of rectangular microstrip patch antenna due to its own lowest order dominant TM
₁₀
mode has been investigated thoroughly. The nature of the field distribution beneath the patch is found to be the key reason for cross polar radiation of such patch antenna. A quick hand computer aided design formulation has been proposed to compute the approximate cross polar radiation peak gain as well as its position in elevation plane. Based on the theoretical view, a simple single layer T shaped microstrip antenna has also been proposed for the improvement in cross polarization suppression of rectangular microstrip antenna.