Compact broadband gap-coupled shorted L-shaped microstrip antennas

Microstrip antennas (MSA) have several advantages, such as, lightweight, small volume and low profile planar configuration. However, their VSWR bandwidth is small and also its size is large in the UHF range (300 - 3000 MHz). The size reduction has been obtained by using either shorting posts or by cutting slots in the conventional MSAs. A shorted L-shaped MSA configuration has been proposed. The bandwidth has been increased by using gap-coupled multiresonator technique. These antennas have been analyzed using IE3D software based on the method of moments followed by experimental verifications.