i/q Mismatch Compensation Circuit for Low IF Receiver

A low-IF receiver and mismatch compensation technology, applied in the field of compensation circuits, can solve the problems of increasing circuit scale and inability to correct amplitude mismatches, etc.

Active Publication Date: 2016-10-05
杭州中科微电子有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This invention has high correction accuracy and high integration, but it cannot correct the amplitude mismatch. Moreover, as the range of phase mismatch that needs to be corrected increases, the scale of the circuit will also increase.
[0006] The widely used solution is to eliminate in the digital domain, using ADC and DSP to use a variety of baseband processing algorithms to eliminate in the digital domain. This design can simultaneously eliminate the mismatch caused by the asymmetry of the complex filter and amplifier, but due to the High image rejection ratio requires high-precision ADC and high-speed DSP, which is at the cost of cost and power consumption

Method used

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  • i/q Mismatch Compensation Circuit for Low IF Receiver
  • i/q Mismatch Compensation Circuit for Low IF Receiver
  • i/q Mismatch Compensation Circuit for Low IF Receiver

Examples

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Embodiment Construction

[0054] Such as image 3 As shown, in a preferred embodiment, the low-IF receiver I / Q mismatch compensation circuit 1 of the present invention includes a mismatch detection module 11, a compensation value update module 12, a mismatch compensation module 13 and a control logic module 14 . Among them, the two input terminals of the I / Q mismatch compensation circuit 1 of the low-IF receiver receive the signal I from the I channel and the signal Q from the Q channel respectively, and after being compensated by the I / Q mismatch, the two output terminals respectively output signal I_C and signal Q_C.

[0055] Specifically, signal I as signal I real , the signal Q (that is, the signal Q_C) passed through the mismatch compensation module 13 is taken as the signal Q real , signal I_C as signal I ideal , and signal Q_C as signal Q ideal , the mismatch detection module 11 obtains the amplitude mismatch α and the phase mismatch β of the Q channel relative to the I channel according to...

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PUM

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Abstract

The invention discloses an I / Q mismatch compensation circuit of a low-intermediate frequency receiver. The I / Q mismatch compensation circuit is used for performing I / Q mismatch compensation on a first signal from an I channel or a second signal from a Q channel and comprises a mismatch detection module, a compensation value update module and a mismatch compensation module, wherein the mismatch compensation module receives the first signal, the second signal and output of the compensation value update module and outputs the compensated first signal and / or the second signal, the mismatch detection module receives the first signal and the second signal and outputs amplitude mismatch and phase mismatch, and the compensation value update module updates an amplitude and phase mismatch corrected value according to the amplitude mismatch and the phase mismatch. The I / Q mismatch compensation circuit of the low-intermediate frequency receiver compensates I / Q mismatch in a digital domain and is simple in principle and high in transferability. When the I / Q mismatch changes suddenly, the I / Q mismatch compensation circuit can obtain a stable compensation value in two update periods, react quickly and have flexible function expansion.

Description

technical field [0001] The invention relates to a compensation circuit, in particular to an I / Q mismatch compensation circuit of a low intermediate frequency receiver. Background technique [0002] In recent years, based on the use of quadrature down-conversion structure, low-IF receivers have been widely used. Low-IF receivers have the advantages of superheterodyne receivers and zero-IF receivers, that is, small DC offset interference, 1 / f noise The effect of interference is small, but there is a problem of image signal interference in low-IF receivers. The signal received by the antenna is turned into two signals in phase and quadrature after a quadrature down-conversion by the mixer. However, since the local oscillator cannot accurately generate signals with a 90° phase difference, the amplifier and the complex filter itself in the post-mixing stage The structural asymmetry of the I / Q circuit will also cause the amplitude and phase mismatch of the I / Q channels. Therefore...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04B1/16
Inventor 胡伟迪何文涛李晓江
Owner 杭州中科微电子有限公司
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