Two-Dimensional Scanning Phased Array With Large Element Spacing Using Pattern Reconfigurable Stacked Patch Antenna at Ka-Band

A 2-D scanning phased array with large element spacing using pattern reconfigurable stacked patch antenna at Ka-band is presented. The pattern reconfigurable stacked patch antenna is composed of four patches on the top integrated with four p-i-n diodes and a driven patch on the lower layer, where the top patches are located along the diagonals of the proposed antenna. By switching the reverse/forward bias states of p-i-n diodes, the phase gradients in different directions are generated and beam steering on the E-, D-(diagonal), and H-planes can be delivered. Subsequently, a 2-D scanning $4\times 4$ phased array with large element spacing is proposed by applying the pattern reconfigurable stacked patch antenna. The 2-D space is divided into nine subsets and covered by nine states of the proposed antenna. The measured results show that a scanning range of ±55° on the E-, D-, and H-planes can be provided. The maximum realized gain is 20.9 dBi at 26.5 GHz with an aperture efficiency of 62.0%. Compared with conventional half-wavelength phased array, the complexity and cost can be reduced for 2-D scanning phased array by introducing the proposed pattern reconfigurable stacked patch antenna.