Abstract
The paper reports experimental findings on the radiation characteristics of AMPA with the variation of location of the active device (two terminal Gunn diode in our case) on the microstrip patch antenna. Five rectangular patches are designed at two frequencies of 9.5 and 9.0 GHz. Radiation efficiencies and characteristics of the patches show the dependence of the position of the active device on the patches. The proper device location has been determined theoretically, which is corroborated through experimental findings.