Design of a Novel Balanced High-Order Subharmonic Self-Oscillating Mixer

The design of RF and millimetre-wave receiver demands for low-cost feature and compact architecture. Self-oscillating mixers (SOMs) are excellent choices for such design as both the oscillating source and the mixer are combined in one single device. Moreover, subharmonic operation reduces LO frequency requirements and therefore opens up interesting perspectives for high-end millimetre-wave systems. In this Letter, we present a fully-balanced third harmonic SOM structure operating at 5.8 GHz with high measured conversion gain (max. 8.75 dB) that is used as a frequency-scaled prototype for future millimetre-wave circuits. To the authors’ knowledge, this is the first presentation of such a circuit structure.