Broadband monolithic single and double ring active/passive mixers

Several double balanced multi-octave bandwidth mixers, comprised of active center-tapped baluns and diode rings are discussed that were fabricated using planar monolithic circuit technology. This novel balun topology uses common gate and common source circuit techniques, so that an ideal 180 degrees phase shift occurs for the signals present between the upper and lower halves of the circuit. The balun exhibits excellent balance through the design band on 2-18 GHz. The performance of a center-tapped balun, designed to operate throughout the 2 to 18 GHz frequency band, is described for both up-converter and down-converter mixer designs.<>