Low-phase-noise quadrature voltage-controlled oscillator

Abstract

The invention belongs to the technical field of radio frequency wireless transmitter/receiver integrated circuits, and particularly relates to a low-phase-noise quadrature voltage-controlled oscillator which can be applied to the wireless transmitter/receiver integrated circuits. The low-phase-noise quadrature voltage-controlled oscillator is composed of two LC voltage-controlled oscillators, two pairs of capacity coupling pipes and split-conversion offset pipes. Through the split-conversion-offset technology and the capacity-coupling technology, a novel quadrature voltage-controlled oscillator circuit is designed, compared with a traditional quadrature voltage-controlled oscillator, the novel circuit is added with output swings, 1/f noise is lowered, and phase noise is lowered. The quadrature voltage-controlled oscillator has the advantages of being low in phase noise, simple in structure, small in chip area, and the like.

Description

technical field [0001] The invention belongs to the technical field of radio frequency wireless transmitter / receiver integrated circuits, in particular to a quadrature voltage-controlled oscillator (Quadrature Voltage-Controlled Oscillator, QVCO) with low phase noise. Background technique [0002] In recent years, the rapid growth of the wireless communication market has promoted the development of high data-rate transceivers, such as direct conversion transceivers, which can reach a very high level of integration. In order to increase the data transmission speed and avoid the loss of information, two transceivers with quadrature signal processing channels are generally selected. Such an accurate quadrature phase output local oscillator source has become a key module in modern wireless transceivers, and it is also a Difficulty in design. At present, there are usually three methods to generate quadrature signals. One is to use RC-CR polyphase filter network. The disadvantage...

AI Technical Summary

Problems solved by technology

At present, there are usually three methods to generate quadrature signals, one is to use RC-CR polyphase filter network, the disadvantage of this method is high power consumption and mismatch of passive resistance and capacitance devices

The second method is the two frequency division method. The main disadvantage of this method is that it needs twice the reference frequency and a two frequency division circuit, so it will require more power consumption; the third method is to use the inductor-capacitor quadrature voltage control oscillator (QVCO), this typical structure is as figure 1

Transistors are coupled in parallel, such as figure 1 As shown, it limits the frequency tuning range of the oscillator, degrades the phase noise, affects the oscillator amplitude and the quality factor of the resonant cavity

Using series coupling will overload the oscillator, limiting the operating frequency and frequency tuning range of the oscillator

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