A Novel Technique for Millimeter-Wave Receivers Using Multiple-Element High-Order Subharmonic Self-Oscillating Mixers

A novel technique for multiple-element phased high- order subharmonic self-oscillating mixers (SOMs) is presented. SOMs are excellent choices for a low-cost receiver design as both the oscillating source and the mixer are combined in one single device. The presented structure is of high interest for high-end millimeter-wave systems as subharmonic operation reduces local oscillator (LO) frequency requirements. In this paper, an outline of the basic theory and a general design procedure for arbitrary mixing orders are presented, and a 6^th-order SOM is fabricated for the first time to the authors´ knowledge in order to verify the proposed technique. The prototype exhibits a conversion gain of +2.8 dB at an RF input frequency of 7.4 GHz. In this paper, the design of the complete circuit structure is presented in theory and verified with measured results.