Millimeter-Wave Transmission-Line Reflectionless Filters

TL;DR

This paper presents the design and fabrication of millimeter-wave reflectionless filters operating at 100 GHz and 230 GHz, achieving high stopband absorption up to 500 GHz, with experimental results aligning well with theoretical predictions.

Contribution

First successful implementation of reflectionless filters at millimeter-wave frequencies using advanced thin-film fabrication on Alumina substrates.

Findings

Filters operate effectively at 100 GHz and 230 GHz

Stopband absorption achieved up to 500 GHz

Measurements agree with theoretical models

Abstract

We report on the development of transmission-line reflectionless filters operating with passbands at 100 GHz and 230 GHz, and stopband absorption up to 500 GHz, the highest operating frequencies yet recorded for such filters. The designs are based on a previously reported mathematical solution to the reflectionless condition, now successfully implemented for the first time, using an advanced thin-film fabrication process on Alumina substrates. Sub-millimeter wave wafer probe measurements show good agreement with theory.