A review of various methods of phase and frequency synchronization of active MMIC based transmit/receive modules is presented, and particular emphasis is placed on the synchronization of oscillators through the use of an indirect subharmonic optical injection locking technique. In this approach, the nonlinear behavior of large-signal modulated laser diodes and solid-state oscillators is exploited to extend the bandwidth of the synchronizing link to the millimeter-wave frequency range. Experimental results of the phase and frequency coherency of two 21.5 GHz FET oscillators are reported. Optimum performance is achieved at a subharmonic factor of 1/4, with a locking range of 84 MHz and a phase noise degradation of only 14 dB. The phase coherency measurement of two injection-locked oscillators points to a phase shift, which is introduced as a result of the frequency detuning between the slave and master oscillator signals. A scheme to correct for this phase error is presented. >

Optical synchronization of millimeter-wave oscillators for distributed architecture

Unified analytical expressions predicting the locking range for fundamental, subharmonic (n=2), superharmonic (n=2), and parametric injection (m=n=p=1) locking are presented and compared in this paper. Power series are employed to model the device nonlinearity. The /spl alpha/-parameters, relating nonlinear I-V behavior, are extracted using a harmonic-balance approach. These expressions are verified using an UHF oscillator; and good agreement is obtained between the experimental and analytical results.

A unified analytical model and experimental validations of injection-locking processes

This paper presents an experimental study on modulated sidebands in the output spectrum of a millimeter-wave (mm-wave) CMOS voltage controlled oscillator (VCO). The results are used to calculate the injected current into the resonant tank in dependence on its locking range. The evaluated parameters are a measure of the oscillator's sensitivity regarding injected periodic interferences. This is of interest when implemented in highly integrated systems, as e.g. in system-on-chip solutions.

Experimental study of injected interference effects on modulated sidebands in CMOS LC VCO

A new injection locking process is proposed and demonstrated experimentally, where a low-frequency injection signal can be used to lock an ultra-high frequency solid-state oscillator. This process has much wider locking bandwidth than the conventional subharmonic injection locking.

H. Okamoto

Papers

Injection Locking of an IMPATT Diode Oscillator by Using a Low-Frequency Signal Parametric Injection Locking