Stacked slot-coupled printed antenna

Abstract

An aperture-coupled microstrip stacked patch antenna is studied with the goal of obtaining wide bandwidth, low cross-polarization, and weak parasitic radiation from the feeding aperture for applications in printed phased array antennas. Recently, it has shown that the poor bandwidth of this type of antenna can be increased by coupling the resonant patch to the slot near its resonance. In this case, although the bandwidth is increased drastically, this technique induces a quite high back radiation level, due to the proximity of the resonance of the slot that radiates on both sides of the ground plane. To alleviate this problem, stacked patches were used to achieve the bandwidth. In this case, the resonance of the slot is chosen to be as far as possible from the operating band of the antenna so that its radiation level will be small. The comparison of the calculated and measured impedance loci of C band antenna shows good agreement.