Mutual Synchronization for Power Generation and Beam-Steering in CMOS With On-Chip Sense Antennas Near 200 GHz
In this paper, we introduce the concept of near-field synchronization as an efficient, scalable, and robust method to synchronize a 2-D array of mutually coupled oscillators for beam-forming at frequencies above f_(max) of a technology. The method employs an array of on-chip sense antennas to probe electromagnetic near-fields of the on-chip radiators. These sense antennas are then coupled to each other appropriately through a network that establishes the synchronized state as the lowest energy state. A circuit-electromagnetic co-design methodology is employed to demonstrate beam-steering near 200 GHz with a synchronized 2 × 2 array. Each element of the array is a traveling-wave oscillator with the nonlinear active devices selectively radiating its second harmonic through the same electromagnetic structure. The beam-pattern can be varied by more than 70° in both azimuth and elevation. The chip is realized in 65-nm bulk CMOS.
© 2015 IEEE. Manuscript received September 19, 2014; revised February 20, 2015; accepted July 06, 2015. Date of publication July 31, 2015; date of current version September 01, 2015. The authors would like to thank Prof. J. Zmuidzinas, Prof. G. Blake, D. Miller, Dr. P. Siegel, Prof. D. Rutledge, and Dr. Sandy Weinreb for technical discussions and providing some of the measurement equipments.