3D-printed High-Directivity H-plane Horn Antenna with High Front-to-back Ratio Using Soft and Hard Walls

Abstract

We employ hard and soft walls to improve antenna directivity and front-to-back ratio of an H-plane horn antenna. Design of this class of antenna has been limited by fabrication methods. While machining methods limit fabrication of 3D designs with complex interior shapes, SIW technology restricts the design to planar structures, foregoing benefits of 3D designs and forcing use of dielectric materials that are lossy. With the advent of 3D-printing technology for antenna and microwave devices, however, 3D hard and soft walls can be integrated in an H-plane horn antenna, improving its performance, which is not possible with conventional fabrication methods. Here, an H-plane horn antenna is designed and 3D-printed at X-band. Using hard and soft walls, directivity and front-to-back ratio are improved by 2.25 dB, and 13.7 dB, respectively, compared to an standard H-plane horn antenna, while the bandwidth covers X-band with lower return loss. The measurement results of the 3D-printed and conductive coated antenna are in good agreement with simulations.