A flat aperture antenna composed of a series fed H-plane horn array excited by a ridge gap waveguide horn

This study presents a new structure for planar aperture antennas with a very simple configuration by making use of gap waveguide technology. Applying the concept of H-plane horn in both feeding network and radiating layer results in a flat configuration capable of providing a directive radiation with reasonable impedance bandwidth, high gain and low side lobes. The proposed structure introduces a very simple configuration, which does not face the enhancement of design and fabrication complexity for larger apertures and higher gains. The principle of operation and design procedure for both the radiating layer and feed network are fully discussed in detail. A sample is designed to operate at Ku band, which presents proper radiation performance with the maximum gain of 24.5 dBi, the maximum efficiency of 85% and the side lobe level (SLL) lower than −22 and −13 dB in H- & E-planes, respectively.