A 10-100 GHz Coax To Double-Ridged Waveguide Launcher and Horn Antenna

TL;DR

This paper presents a novel coax to double-ridged waveguide launcher and horn antenna design that offers wide bandwidth, low return loss, and stable beamwidth from 10 to 100 GHz, suitable for high-frequency applications.

Contribution

The paper introduces a new launcher design with symmetric probes and a horn with a monotonic cutoff frequency variation, improving bandwidth and suppressing trapped modes.

Findings

Achieves over 15 dB return loss across 10:1 bandwidth.

Provides nearly constant beamwidth and about 16.5 dB directivity from 10-100 GHz.

Demonstrates effective suppression of trapped mode resonances.

Abstract

The design, fabrication, and measurement of a coax to double-ridged waveguide launcher and horn antenna is presented. The novel launcher design employs two symmetric field probes across the ridge gap to minimize spreading inductance in the transition, and achieves better than 15 dB return loss over a 10:1 bandwidth. The aperture-matched horn uses a half-cosine transition into a linear taper for the outer waveguide dimensions and ridge width, and a power-law scaled gap in order to realize monotonically-varying cutoff frequencies, thus avoiding the appearance of trapped mode resonances. It achieves a nearly constant beamwidth in both E- and H-planes for an overall directivity of about 16.5 dB from 10-100 GHz.