A 40/50 GHz diplexer realized with three dimensional copper micromachining

This paper describes the design and measurement of a millimeter-wave (40/50GHz) diplexer fabricated using a three dimensional metal micromachining process. The measured diplexer has channels at 40.8 GHz and 51.1 GHz with fractional bandwidths of 2.36 GHz (5.8%) and 2.07 GHz (4.05%) and midband insertion loss of 1.58 dB and 3.52 dB, respectively. The diplexer measures 7.0 mm × 3.9 mm × 0.745 mm. It is fabricated from two comb line filters realized with microfabricated stripline resonators. The three-dimensional copper metal micromachining process utilized to fabricate the diplexer has demonstrated integration with active components and the diplexer is fabricated on wafer with a variety of other passive components.