Wide-band MMIC Kowari mixer/phase shifters

A series of wide-band image-reject monolithic-microwave integrated-circuit mixer/phase shifters were designed, fabricated, and tested for operation in the microwave and millimeter-wave bands. Mixers based on diode and resisti ve-high electron-mobility transistor (HEMT) nonlinear elements are presente d and compared in this paper. The diode-based Kowari (we christened our mod iaed "rat-race" mixer "Kowari" after the common name of the small and somew hat rat-like carnivorous brush-tailed marsupial mouse, Dasyuroides byrnei, which inhabits the arid regions of central Australia) mixers have a bandwid th of approximately 15%, with up- and down-conversion loss [RF to/from TF t in this paper, we use "IF, "LO," and "RF" to label the ports associated wit h particular signals, not necessarily to describe the nature of the signals themselves)l less than 10 dB and up-conversion output power greater than 0 dBm, At band center, the down-conversion loss is approximately 7 dB, The n ovel resistive-HEMT-based Kowari mixers have a measured IF-to-RF up-convers ion loss of approximately 2 dB and LO-to-RF conversion loss of approximatel y 13 dB over 17-25.5 GHz. While both circuit types realize wide-band 360 de grees phase shifters when appropriate control voltages are applied, the res istive-HEMT-based Kowari has better linearity and a smaller insertion loss.