A 20-GHz-band subharmonically injection-locked oscillator MMIC with wide locking range

Abstract

A monolithic subharmonically injection-locked oscillator (ILO) with wide frequency tuning range using a shunted varactor diode inserted to the oscillation loop is presented. A 20-GHz-band ILO is fabricated that achieves the wide injection locking range of more than 700 MHz at each subharmonic factor up to 32. In addition, the phase-noise degradation rate of the ILO against the subharmonic factor is close to 6 dB/oct. The ILO configuration is extremely suitable for realizing lowcost and low-phase-noise millimeter-wave monolithic microwave integrated circuit (MMIC) sources.

A Very High-Order Subharmonically Injection-Locked Oscillator Using a Resonant-Tunneling HEMT

“…To our knowledge, this is the highest order ever reported form an ILO. Adding a frequency-tuning function such as a variable phase shifter in the oscillation loop is an effective solution to widen the locking range [8], though the measured locking range for higher subharmonics would be narrowed. The measured power levels of harmonics obtained from the RTHEMT are independent of reference signal frequency, and thus the proposed ILO is applicable for millimeter-wave operation.…”

HEMT Oscillators for Millimeter Wave Systems in Coplanar Waveguide Technology

“…No additional components such as frequency dividers and phase comparators for a PLL, or RF filters and amplifiers for the multiplier are needed. Subharmonic injection locked oscillator MMICs have been reported up to V-band [12][13][14].…”