Broadband space-fed array with stacked microstrip array as feed element

Higher order space-fed arrays have limited gain due to unequal excitation of patches when fed by a single microstrip patch. Hence, a broadband space-fed array with a stacked microstrip array as the feed element is proposed. An array of rectangular microstrip antennas is placed on top of a co-axially fed broadband E-shaped patch antenna to realize a multi-layer stacked microstrip array. First, various configurations of the stacked microstrip array, like the 1 × 3, 3 × 1, plus shaped and 3 × 3 arrays, are studied. The 3 × 3 array yields an optimum gain of 8.25 dBi and a bandwidth of around 2.2 GHz. The 3 × 3 stacked array is then used as a feed element for a 3 × 3 space-fed array which yields a gain of 14.4 dBi and bandwidth of 2.15 GHz.