Compact single feed circularly polarized Koch island microstrip antenna

Single feed microstrip antenna using Koch curve as boundary to the Triangular patch to get circular polarization is presented. With the proposed antenna it is shown that the size can be reduced by more than 50% without much reduction in gain of the antenna. The antenna provides almost constant gain of about 4 dBi over the frequency band of operation. It gives a good circular polarization with minimum axial ratio close to 0 dB at the center frequency of 2.4 GHz. 3 dB axial ratio bandwidth of about 1.3% is obtained with the proposed antenna. Measurement results are compared with simulated results and a very good agreement is obtained.