Experimental study of broadband dual-frequency circular patch antennas

A novel design of a slot-loaded circular microstrip antenna with broadband dual-frequency operation is proposed and experimentally studied. The two operating bands of the proposed antenna are of the same polarization planes and also have similar radiation characteristics. The proposed dual-frequency design can also provide a tunable range of about 1.28 to 1.59 for the frequency ratio of the center frequencies of the two operating bands. For constructed prototypes studied here, wide impedance bandwidths of about 7.0 to 9.6 % for the lower band and 16.1 to 24.4 % for the higher band are obtained.