A Digitally Controlled Injection-Locked Oscillator With Fine Frequency Resolution

Abstract

We propose a digitally controlled injection-locked RF oscillator with an auxiliary loop as an alternative to the conventional capacitive fine-tuning of an LC-tank. The oscillator is injection locked to a time-delayed version of its resonating voltage and its frequency is modulated by manipulating the phase and amplitude of injected current. The injection strength can be programmed for the DCO step size to be as fine as 9 kHz at 4 GHz. Alternatively, with large injection strength, the tuning range can reach up to 200 MHz. The proposed oscillator is experimentally verified in TSMC 40 nm digital CMOS.Index Terms-All-digital PLL (ADPLL), digital phase rotator (DPR), digital-to-frequency converter (DFC), digitally controlled delay (DCD), digitally controlled oscillator (DCO), multi-stage noise ΣΔ (MASH).

Microplastic Detection in Soil and Water Using Resonance Microwave Spectroscopy: A Feasibility Study

“…The typical frequency tuning resolution of the phase-lockedloop microwave transmitters and receivers [46], [47] is in the range 10 -5 -10 -8 , which indicates that the theoretical microwave spectroscopic resolution of microplastic concentrations in the environment at tens of ppm level is possible, considering microwave circuitry frequency tuning characteristics. it can be seen that higher Q factors of the sensing probe allow better contaminant resolution, however even for Q=2500, the concentration resolution is limited to 100ppm (at the RX sensitivity level -100dBm).…”

Numerical Model of an Injection-Locked Wideband Frequency Modulator for Polar Transmitters

“…Our proposed solution generates FM through injection locking, as shown in Fig. 7 [12] where the oscillator is injected with a current I inj e j θ that is a θ phase delayed version of its resonating voltage V osc . The frequency of the injection-locked oscillator ω out under such a condition can be derived from Adler's equation [14] ω…”

“…The circuit enclosed by the dashed line in Fig. 8 is the ILFM that was fabricated and tested in [12]. All measurements in that work were performed in open-loop configuration and without the ADPLL.…”

Oscillator-based ADCs: An exploration of time-mode analog-to-digital conversion

“…An alternative approach would be to linearise the oscillator at circuit level, thus inherently solving its nonlinearity. It has been shown by using the RF principle of injection-locking [1], the oscillator frequency tuning curve can be made reasonably linear thus improving the dynamic range of the ADC. The concept of self-injection locking is shown in Fig.…”

“…As a consequence, the central efforts of the research community have been to linearise the VCO at system and circuit level. To that end, this paper offers the possibility of inherently linearising the oscillator at circuit level by leveraging on the RF principle of injection locking [1].…”