Analysis of series-fed microstrip array antennas

Series-fed array of square patches designed at 10 GHz, with three different configurations has been analyzed for sidelobe level and cross-polarization characteristics. A series-fed 8×2 planar array is analyzed to provide a sidelobe level of − 24.2dB and cross-polarization level of −21.8dB. The second configuration; a 2-line series array of 8 elements oriented back to back and fed with 180° out of phase exhibits a sidelobe level of − 25dB and low cross-polarization better than −51.6dB over all the angles. In the third configuration, a single line series array of 8 elements displaced on both the sides of the feed line is analyzed. The sidelobe level has been increased to −13.3dB with maximum cross-polarization level −27.7dB. The impedance bandwidth of 220MHz, 270MHz and 350MHz for a VSWR of 2, is observed for the three antenna types respectively.