Non-Identical Rectangular Microstrip Antenna Arrays for Amplitude Tapering

ABSTRACTA design technique of an antenna array with amplitude distribution/tapering to suppress the first side lobe level by exploiting the property of the rectangular microstrip antenna (RMSA) is proposed. Non-identical antenna array elements have been designed using the RMSAs by varying their width and hence the gain (keeping the length and hence the frequency same) to obtain the amplitude distribution for a desired first side lobe level. This eliminates the need of a complicated feed network with unequal power division to realize amplitude tapering. The conceptualized design is verified for a number of corporate-fed arrays and an analysis is carried out to give design guidelines with respect to the number of elements in the array. A symmetric corporate-fed 8-element antenna array with a cosine-square over pedestal amplitude distribution, operating at 1.8 GHz, has been designed and fabricated to validate the proposed concept. There is a reasonable agreement between simulated and measured results.