A Compact and Monolithically 3-D Printed Millimeter-Wave High-Gain Horn Antenna

This paper presents a compact and monolithically integrated Ka-band high-gain horn antenna built with 1-to-16 waveguide power dividing networks. The horn antenna consists of a 2-way H-plane power divider, two 2-way E-plane power dividers, and four 4-way E-plane power dividers, forming an 8 x 2 radiation aperture array aiming to maximize the in-band realized gains with stringent size requirement. The constituent waveguide power dividers are shaped with exotic iris geometries, allowing for radiation of quasi-plane waves with wideband impedance matching and enhanced structural compatibility with 3-D printing technology. The antenna is manufactured mono-lithically by incorporating high-precision Polyjet 3-D printing and electroless copper/silver plating processes. The 3-D printed antenna demonstrates excellent radiation patterns in a -15-dB impedance bandwidth from 26.5 to 30.5 GHz with in-band realized gains of 17.1-18.3 dBi.