Compound techniques for broadening the bandwidth of microstrip patch antenna

By using compound techniques to broaden the bandwidth of a microstrip patch, a new type of stacked microstrip patches antenna which increases the frequency bandwidth significantly is investigated. When the feed point is placed at the common symmetric line of upper and lower patches, by means of controlling the relative patch dimensions and moving the upper patch along the symmetric line; adding two pairs of parasitic conducting bars around the lower patch; and loading a capacitive disk on the feed probe to match its proper inductance, a good result for the frequency bandwidth of about 21% for voltage standing-wave ratio (VSWR) of 2 or less in the L-band (1.2-1.4 GHz) and low cross-polar level in radiation pattern is obtained