Some investigations on multilayer microstrip stacked antenna

277-280The results of investigation on an electromagnetically coupled stacked microstrip antenna have been reported. Experimental work is carried out to study the effect of coupling on various parameters such as pattern, bandwidth, beamwidth, VSWR and input-impedance. The radiated power is found to be maximum for the microstrip stacked antenna with one and two parasitic elements. However, radiated power decreases significantly when the number of parasitic elements in microstrip stacked antenna is more than two. The beamwidth of the main lobe improves with the parasitic elements. The bandwidth of the microstrip antenna is found to depend directly on the number of the parasitic elements. It has been observed that the radiated power depends on inter element spacing with air dielectric in between the elements. An air gap spacing of 2.8 mm is found to provide maximum radiated power from microstrip stacked antenna with single parasitic element. This hints that there is an optimum inter-element spacing that provides maximum coupling and hence maximum radiation