A modified half U-slot microstrip patch antennas with shorting wall

Abstract

The major limitations of microstrip antennas (MSAs) are their narrow impedance bandwidth, small gain and low power handling capability. A half U-slot MSA with shorting wall has been designed and experimentally verified. Its center frequency is observed at 2.66 GHz. The bandwidth is 688 MHz and percentage bandwidth is 25.6% has been obtained while radiation efficiency is above 94% for the operating band. A novel design for increasing the bandwidth of a rectangular patch antenna is introduced and implemented. The design concept involves cutting an extra slot on a half U-slot MSA with shorting wall loading. This new design is very useful since it improves the bandwidth of a traditional U-slot patch antenna with an advantage of reduction in size. Measured VSWR bandwidth of 20 % and average gain of 7 dBi have been achieved. The efficiency is above 95% in the entire operating range.