130-nm CMOS K-Band Two-Element Differential Power-Combining Oscillators

A power-combining structure at
K
-band is proposed. The proposed structure, consisted of a multisection of Marchand baluns in series configuration, combines multiple pairs of balanced signals into a single unbalanced port. The active devices, in a differential cross-coupled pair configuration, are then combined with the multibalun structure forming the CMOS multiple element oscillator. The power-combining mechanism is investigated through
Y
- and
S
-parameters. The power-combination oscillators are implemented in 0.13-μm CMOS technology, demonstrating the ability of monolithic integration. One and two cross-coupled-pair design of oscillator are measured. Experiment results for the oscillators are presented, showing maximum power-combining efficiency of 76.0%.