A 75–110 GHz seventh-harmonic balanced diode mixer in a novel circuit configuration

We report on a novel balanced diode mixer circuit configuration. The mixer operates in a seventh harmonic mixing mode and is fed with the RF signal via a WR-10 waveguide. For a fixed IF of 750 MHz our mixer has very flat characteristics of conversion loss of about 19 dB plusmn 2.5 dB over the entire W-band (75-110 GHz). The mixer is straight forward to design and its fix-tuned hybrid integrated circuit is easy to manufacture. Only commercially available components are necessary. So our mixer design offers a smart and low-cost alternative solution for broadband receivers as well as for frequency extensions of spectrum analyzers and vector network analyzers.