2-LOBE PATTERN FROM RECTANGULAR PATCH BY ELECTROMAGNETIC COUPLING

A rectangular microstrip patch antenna is electromagnetically excited by microstrip line, but fed from the short side. The effect on the rad iation pattern of variation of the feedline inset/offset position is s tudied experimentally. It is observed that the radiation pattern has t wo distinct lobes with variable, asymmetric amplitudes. The angle betw een the two lobes is found to be about 95 degrees +/- 10 degrees. But the lobe amplitudes show a periodic variation with normalized inset fo r each offset value. (C) 1994 John Wiley & Sons, Inc.