LAUSR

This paper presents two new planar aperture antennas (PAAs) with high gain and high aperture efficiency. Each antenna is composed of an opening cavity and differentially fed by the grounded coplanar waveguides at two parallel edges. In order to improve the gain of the original PAA, physical aperture has been extended and patches are introduced on the aperture to uniform the electric field to improve the aperture efficiency. Two corresponding prototypes are designed. Experimental results show that for the first prototype whose aperture is extended in the guided-wave propagation direction, the reflection coefficient can maintain less than −15 dB from 55 to 66 GHz. The maximum gain is 19.7 dBi at 63 GHz with the aperture efficiency of 66.03%, and the 3-dB gain bandwidth is 57–65 GHz. The second prototype, whose aperture is extended in the transverse direction, can achieve −15-dB impedance bandwidth from 56.4 to 66 GHz. The maximum gain is 20.3 dBi at 61 GHz with the aperture efficiency of 63.06%, and the 3-dB gain bandwidth is 57–64 GHz. Due to their outstanding performance and fabrication merits, the proposed PAAs are good candidates for the future cost-efficient fifth-generation wireless systems.