Compact Planar Arrays Based on Parasitic Superdirective Elements

International audienceThis paper addresses the problem of designing compact antenna arrays for UHF band by using small superdi-rective unit-elements. A small parasitic two-element array is designed for 868M Hz European RFID band. This array with a size factor (ka = 1.1) has a total directivity of 7dBi and radiation efficiency of 43.4%. Then this array is integrated in a 2 × 2 planar array. A parametric analysis on the inter-element distance is performed revealing the tradeoffs between the antenna-dimensions,-directivity and-efficiency. A small 2 × 2 antenna array with dimensions of 34 × 34cm 2 presenting a total directivity of 12.6dBi and radiation efficiency of 41% is designed