The microstrip antennas are the low profile radiators. It is so because of their numerous features such as low volume, compactness, low fabrication cost and mechanical robustness. Numerous techniques have been suggested to improve the microstrip patch antenna characteristics. In this paper, the authors discuss the slot coupled patch antenna, one with a rectangular patch and other one with a rhombus shaped patch. And study the antenna characteristics of both the antenna such as bandwidth, radiation loss and gain. The results indicate the impact of changing patch on the antenna performance.