Fully integrated 94-GHz subharmonic injection-locked PLL circuit

Abstract

A new integrated W-band frequency source MMIC is presented which consists of a 94-GHz voltage-controlled oscillator (VCO) with large tuning range and a phase comparator, forming a subharmonic injection-locked phase-locked loop (ILPLL). The ILPLL combines conventional injection-locking with an additional phase control loop to improve the locking range of the oscillator significantly. The 4th subharmonic frequency is used as the reference signal. The locking range was increased from 80 MHz without ILPLL to 4.5 GHz with ILPLL by closing the loop with an external dc amplifier. A phase noise of -83 dBc/Hz at 100-KHz offset was achieved. Pseudomorphic GaAs HEMT's and a coplanar circuit topology were used to allow integration into complex single-chip subsystems and flip-chip packaging

Trends and Challenges in Coplanar Millimeter-Wave Integrated Circuit Design

“…Fig. 8 shows a chip photograph of a integrated W-band frequency source MMIC [12]. The circuit consists of a 94-GHz voltage controlled oscillator, which can be stabilized by subharmonic injection locking using the 4th to the 6th subharmonic.…”

Gen-Adler: The generalized Adler's equation for injection locking analysis in oscillators

“…Injection locking is exploited in the frequency synthesis and related applications. For example, it is used in the design of high performance quadrature oscillators [1], [2] and injection locked phase-locked loops (PLLs) [3]. Injection locking also has wide applications in optics [4], [5].…”

Analysis and design of sub-harmonically injection locked oscillators

“…The phenomenon, together with the related effect of injection pulling, has often been regarded as an unwanted disturbance, causing, among other things, malfunction in serial clock/data recovery, increased timing jitter and clock skew, increased BER in communications, etc.. Over the years, however, IL has also been put to good use in electronics -e.g., for quadrature signal generation [4]; for microwave generators in laser optics [5]; for fast, low-power frequency dividers [6]; and in PLLs [7] and wireless sensor networks [8]. Moreover, IL is an important enabling mechanism in biology (e.g., [9], [10]).…”

“…It is also possible, however, for oscillators to phase-lock at a frequency that is an exact integral sub-multiple of the frequency of the externally applied signal; this is termed subharmonic IL (or SHIL, described further in Sec. II-B) and is useful in frequency division applications [6], [7]. Design of circuits exploiting SHIL has tended to rely predominantly on trial-and-error based methodologies, using brute-force transient simulations to assess impact on SHIL-based circuit function.…”