An experimental study of the printed-circuit circular disc antenna

Using Watkins' dominant mode design for a circular resonant structure in microstrip, several circular disc radiators were fabricated on a copper-clad laminate of teflon/glass using conventional printed- circuit board etching techniques. The input impedance and far field patterns of these antennas were measured as a function of feed position and dielectric thickness. The effect of a cross-polarizing of the radiators was also measured assuming that Watkins' surface current distribution on the disc for the n=l mode would result in a linearly polarized radiation. Finally, a comparison between the measured and theoretical radiation properties is presented for various combinations of antenna feed position and dielectric thickness.