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Remote Frequency Calibration of Passive Wireless Microsystems
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
When two oscillators with different but close frequencies are weakly coupled, they synchronize each other such that in the steady state they both oscillate at the same frequency. First observed by Christiaan Huygens, the inventor of pendulum clock, this phenomenon is known as injection locking. A detailed study of the injection-locked oscillator is available in [6]. Since injection locking can synchronize the frequency of an oscillator to that of its injection-locking signal of small amplitude, it has been widely used as a power-efficient means for clock recovery and phase locking in RF and mixed-mode circuits.
Injection Locking
Published in Daniel B. Talbot, Practical Analog and RF Electronics, 2020
One application of injection locking is to make low noise frequency dividers since the slave can be an oscillator of 1/N times the master injection frequency. Another application is to transfer the signal purity of the master to the slave (e.g., clean up the phase noise sidebands of a magnetron to more closely match the lower phase noise of the master signal).
New tunable phase oscillator structure
Published in International Journal of Electronics Letters, 2022
A. S. Elwakil, Costas Psychalinos, Brent Maundy
The design of tunable-phase oscillators is a relatively new topic and has not yet received much attention in the literature apart from the special case of quadrature-phase oscillators which are needed for communication systems (Elamien et al., 2020). Multi-phase oscillators are important for a growing number of applications and are usually based on LC resonant oscillator structures (Andreani and Wang, 2004; Romano et al., 2006, and Seifi and Miar-Naimi, 2014) with a special focus on quadrature-phase oscillators (Ghonoodi and Naimi 2011, 2016). Injection locking has also been used to generate multi-phase oscillators (Lopez-Villegas et al., 2005) as well as other techniques such as using logarithmic domain circuits (Panagopoulou et al., 2013), coupling together two or more oscillators (Pourahmad et al., 2019) or using optoelectronic devices (Gao et al., 2013; Wu et al., 2016). Recently, a four-output phase-tunable oscillator based on cross-coupling two differential pair cells was introduced and verified in Maundy et al. (2017). Another phase-tunable oscillator based on a third-order non-symmetrical cross-coupled structure was proposed by Elwakil and Maundy (2019). It can be recognised from all the above that the majority of the available phase-tunable oscillators are transistor-level circuits although arbitrary-phase shift oscillators were proposed in Tu et al. (2012) based on using Operational Trans-resistance Amplifiers (OTRAs).
Low power differential colpitts injection-locked frequency dividers using 0.18 μm CMOS technology
Published in International Journal of Electronics Letters, 2018
Mohammad Jafar Hemmati, Mohsen Saneei, Somaye Asadian, Ahmad Hakimi
In this work, two new low power and low noise LC FDs based on colpitts voltage-controlled oscillator (VCO) are proposed. Operation mechanism of the proposed circuits is based on injection-locking phenomenon. Based on the injection-locking phenomenon, when an external periodic signal is injected to an oscillator (either ring oscillator or LC-tank oscillator) with a frequency close to its free running frequency or one of its harmonics, the oscillator will lock to the injected signals. In the next section, two types of more usable (divide-by-2 and divide-by-3) ILFDs are discussed. Next, in Section 3, two new colpitt-based LC injection-locked frequency dividers (LC-ILFDs) in which one of them is divide-by-2 and the other is divide-by-3 are proposed and analytically discussed. The simulation results of the proposed circuits are presented in Section 4. In the final section, a summary of the important points of this work is provided.