A D-Band Manifold Triplexer With High Isolation Utilizing Novel Waveguide Dual-Mode Filters

Abstract

This letter presents our design of a wideband manifold-coupled triplexer with high isolation in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</i> -band. The basic structure of channel filters is the novel TM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">120</sub> and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">101</sub> dual-mode cavity, which provide two reflection zeros and one transmission zero. To achieve good computational efficiency and design accuracy, the space-mapping technique, consists of a coarse distribute model and a fine full-wave electromagnetic model, is adopted in the development of the triplexer. The proposed triplexer is fabricated by high-precision computer numerical control milling technology. The measured results are all in good agreement with the simulated ones. The measured lowest in-band insertion loss is 0.54/0.62/0.55 dB for three channels, respectively. The return loss of each channel is better than 14 dB and the isolation between each channel is better than 45 dB.