Low-noise digital control LC oscillator using the back-to-back serial MOS varactor

Abstract

The present invention pertains to the field of the design technology of wireless communication system transceiver chip. The characteristics reside in that: the novel back-to-back series connected type MOS varactor adopting the digital signal control forms the main hypercap part of the numerical controlled LC oscillator, and the phase noise converted from the amplitude noise from the oscillator is reduced, and the restraining ability of the oscillator to the noise from the current source is improved, thus, the phase noise of the output signal of the oscillator is finally reduced. The method in the present invention, comparing with the prior method, can improve the performance of the on-piece CMOS oscillator and reduce the power consumption of the oscillator effectively, thus, the method is useful to the reduction of the manufacturing cost and power consumption of the receiver.

Description

technical field [0001] The invention relates to a novel on-chip CMOS low-noise numerical control LC oscillator using back-to-back series MOS varactors, and is especially suitable for the design of CMOS integrated chips for wireless communication system transceivers. Background technique [0002] The rapid development of the personal communication market requires that the personal handheld terminal of the communication system is increasingly developing in the direction of low cost, low power consumption, miniaturization, and support for multiple modes of operation. The only way to meet the above requirements is the integration of transceiver chips. Realize the so-called system on chip (SOC: System On Chip), that is, integrate the radio frequency, analog and digital modules of the transceiver on one chip as much as possible, and at the same time reduce the number of discrete components outside the chip as much as possible. With the continuous shrinking of CMOS integrated circu...

AI Technical Summary

Problems solved by technology

However, the common disadvantage of the above-mentioned oscillators is that when the oscillator is working, it is in a large-signal state, which makes the varactor work in a nonlinear state, thereby converting the amplitude noise of the oscillator into phase noise, which increases the noise of the oscillator to the tail current tube. sensitivity, thereby deteriorating the phase noise of the oscillator output signal

In order to meet the stringent requirements of the phase noise of the oscillator in the wireless communication transceiver, the current numerically controlled LC oscillator often needs to consume a large amount of power

[0005] To sum up, traditional voltage-controlled oscillators are not suitable for the current development trend of deep submicron technology and system integration, and will face more and more difficulties in the realization of modern wireless communication transceiver chips; The phase noise performance of the numerically controlled LC oscillator is easily affected by the amplitude noise in the circuit, and the power consumption is large, which cannot fully meet the requirements of high performance and low power consumption of modern wireless communication transceivers

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