Method and circuit for tuning lc oscillator frequency based on phase tuning technology

Abstract

A tunable multiphase ring oscillator includes a plurality of stages connected in series in a ring structure, where each stage generating a stage output from a stage input. Each stage of the tunable multiphase ring oscillator includes a plurality of trans-conductance cells, each generating an output from at least one portion of the stage input. Each stage further includes at least one phase shifting module for imparting at least one phase shift to the at least one portion of the stage input, an oscillator unit for generating the stage output from a combination of the plurality of outputs, and means for varying at least one of the plurality outputs so as to adjust a phase of the stage output.

Description

technical field [0001] Generally speaking, the present invention relates to an LC oscillator, and in particular relates to an LC oscillator with multi-phase output using phase modulation and frequency modulation technology. Background technique [0002] In wired and wireless communication systems, LC oscillators that can generate low-noise clocks or local oscillation (LO) signals are critical components. Moreover, modern communication systems often require multiple phase clocks or LO signals. For example, zero-IF receivers require in-phase and quadrature-phase (I&Q) signals for modulation and demodulation, and I&Q signals, such as image-rejected receivers such as Weaver and Hartley, are a prerequisite for operation. condition. In addition, other applications, such as phased array radar and half-sample rate clock and data recovery, also require multi-phase clock or LO signals. [0003] In order to receive or transmit signals on channels of different frequencies, or to cope...

AI Technical Summary

Problems solved by technology

Compared to radio frequency (RF) VCOs, due to poorer quality factor (Q) of tuning capacitors, and severe AM-to-PM noise conversion due to large VCO gains on the order of GHz / V , the spectral purity of the mmWave VCO drops severely

In addition, the more stringent trade-off relationship between the effective tuning ratio and quality factor of the tuning capacitor, and the reduced supply voltage in deep submicron CMOS technology, make the capacitor tuning method more suitable for mmWave VCOs. invalid

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