Broadband D-Band Antenna Array Based on 64 Stepped Horns for 5G Backhauling Applications

This work proposes an 8×8 D-band antenna array constructed from 64 stepped horns. The structure is designed to be machined from single metallic block adhered with an additional bottom metallic cover. The proposed design can be realized using low-cost commercially accessible milling tools. The configuration at hand is composed of three building blocks: transition, power divider and horn radiator. The array footprint has a volume of 30×30×8 mm
³
while a 29.5% fractional bandwidth is achieved from 130 till 175 GHz where reflection coefficient is lower than 7.8 dB. Radiation characteristics are investigated for both single horn radiator and 8×8 antenna arrays where the obtained average gain values are 15.25 and 32 dBi, respectively. Directive pencil beam, required for 5G backhauling communication, has been confirmed for 8×8 antenna array where the half power beam width is 1.5° for both E and H-planes while grating lobes appear at 28°.