Ka- and W-Band Printed Circuit Balanced Mixers

The design and performance of Ka- and W-band broadband integrated circuit mixers are described. The mixers use commercially available low cost diodes. The substrate material consists of RT-Duroid 5880. After a theoretical discussion of diode impedance matching, conversion loss, and isolation, two layouts are manufactured and tested. In Ka-band, there results a conversion loss of 10 dB at 26.5 GHz through 40 GHz and an isolation of 25 dB between RF and LO port. In W-band, the conversion loss amounts to 13 dB at 80 GHz through 100 GHz and an isolation of 20 dB is obtained.