Bandwidth Enhancement Method for Low Profile E-Shaped Microstrip Patch Antennas

A simple bandwidth enhancement method for low profile E-shaped patch antennas is presented. By introducing a distributed LC circuit to the E-shaped patch antenna, a new resonant frequency close to that of the E-shaped patch is obtained, thus the bandwidth is widened. Moreover, the air thickness of the E-shaped patch antennas is reduced to only 0.0344λ₀. A prototype antenna operated at AMPS band (824-894 MHz) was fabricated and measured. Measured results show that the designed low profile antenna has an impedance bandwidth over 9% for VSWR<; 2, with a satisfactory radiation performance within the bandwidth. The proposed method is also applicable to the design of other types of low profile slot-loaded patch antennas.