Rectangular ring and H-shaped microstrip antennas-alternatives to rectangular patch antenna

H-shaped and rectangular ring microstrip antennas have been compared with the commonly used rectangular patch antenna. It has been found that the H-shaped patch antenna is smaller in size (about half), and is broadbeam but with narrow bandwidth. On the other hand, for larger bandwidth and/or narrow beamwidth applications a rectangular ring antenna is better than a rectangular patch antenna. Because of size reduction the H-shaped patch looks attractive for UHF applications.