COMPACT SINGLE FEED CIRCULARLY POLARIZED FRACTAL BOUNDARY MICROSTRIP ANTENNA

摘要

Compact circularly polarized single feed microstrip antenna using fractal curve as boundary is presented. It is shown that by using fractal curve as boundary to the square patch the size can be reduced by more than 50% without much reduction in gain of the antenna. The antenna gives a good circular polarization with minimum axial ratio close to 0 dB at the center frequency of 2234 MHz. Three decibel axial ratio bandwidth of about 0.81% and 10 dB impedance bandwidth of about 3.25% are obtained with the proposed antenna. The antenna provides almost constant gain of about 4 dBi over the frequency band of operation. Measurement results are compared with simulated results and a very good agreement is obtained.