Design and Performance of a W-Band Broadband Finline Diplexer with Over 20 GHz Bandwidth

This paper describes the design and performance of a contiguous 90- to 112-GHz diplexer using the integrated finline technique. State-of-the-art results of 1.5 dB insertion losses have been achieved. There is good agreement between the experimental results and those predicted theoretically; these results demonstrate a significant technological advance of millimeter-wave multiplexer using printed circuit techniques. Results of an extremely wideband H-plane tee with a VSWR of less than 1.4 over the full W-band (75 to 110 GHz) are also presented.