Self-correcting phaselocked loop frequency synthesizer capable of realizing frequency band selection

Abstract

The invention discloses a self-correcting phaselocked loop frequency synthesizer capable of realizing frequency band selection, composed of a phaselocked loop and a self-correction loop; wherein the phaselocked loop is formed by connecting a phase detection discriminator, a charge pump, a loop filter, a voltage-controlled oscillator and a frequency divider in sequence, the self-correcting loop is formed by connecting a phase detection discriminator, a trigger, a controller, a voltage-controlled oscillator and a frequency divider in sequence, and the phaselocked loop and the self-correcting loop share the same phase detection discriminator, the same voltage-controlled oscillator and the same frequency divider. The invention realizes center frequency correction by regulating one group of fixed capacitor of voltage-controlled oscillator, so that widen frequency tuning range can be obtained under lower gain of voltage-controlled oscillator, thus error caused by making process of integrated inductance and variable varactor can be compensated, phase noise of phaselocked loop frequency synthesizer is reduced, and implementation of single chip phaselocked loop frequency synthesizer by adopting CMOS technology can be realized.

Description

technical field [0001] The invention relates to the technical field of frequency synthesizer design in wireless transceivers, in particular to a self-correcting phase-locked loop frequency synthesizer capable of realizing frequency band selection. Background technique [0002] The phase-locked loop frequency synthesizer is a key module in the design of the wireless transceiver. It outputs a series of high-precision frequency signals to provide local oscillator signals for the frequency conversion of the transceiver. The commonly used phase-locked loop frequency synthesizer structure is shown in Figure 1. It consists of a phase-frequency detector, a charge pump, a loop filter, a voltage-controlled oscillator connected in sequence, and a voltage-controlled oscillator connected to the input terminal of the phase-frequency detector. divider between the oscillator outputs. The structure of the voltage-controlled oscillator in the phase-locked loop frequency synthesizer is shown ...

AI Technical Summary

Problems solved by technology

[0005] In the process of wireless transceivers becoming more and more single-chip design, the above factors restrict the high integration of traditional phase-locked loop frequency synthesizers, and it is impossible to realize single-chip design to save costs

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