CN210380817U

CN210380817U - Direct current offset calibration circuit for frequency mixer

Info

Publication number: CN210380817U
Application number: CN201921964312.9U
Authority: CN
Inventors: 袁永斌; 方加元
Original assignee: Shanghai Yb Electronics Co ltd
Current assignee: Zhicode core (Wuxi) communication technology Co., Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-04-21
Anticipated expiration: 2029-11-14

Abstract

The utility model discloses a direct current skew calibration circuit for mixer, including the radio frequency front end module, low-noise amplification module, the mixing module, the transimpedance amplification module, the filtering module, the analog-to-digital conversion module, algorithm module and reference frequency produce the circuit module, the radio frequency front end module is connected with low-noise amplification module, low-noise amplification module is connected with the mixing module, the transimpedance amplification module is connected with the mixing module, the filtering module is connected with the transimpedance amplification module, the analog-to-digital conversion module is connected with the filtering module, the algorithm module is connected with the mixing module, reference frequency produces the circuit module and is connected with the mixing module. The direct current offset calibration circuit for the mixer manufactured by adopting the technical scheme solves the problem of automatic compensation and calibration of the process deviation of the capacitance and the inductance of the radio frequency front-end module in a GNSS/GSM/TD/WCD MA/LTE communication system.

Description

Direct current offset calibration circuit for frequency mixer

Technical Field

The utility model relates to a wireless communication field, in particular to a direct current offset calibration circuit for mixer.

Background

For a zero intermediate frequency receiver system in a communication system, a strong interference signal can generate a strong direct current component, so that a post-stage circuit is saturated, if the interference signal is modulated, the signal to noise ratio (SNR) is directly deteriorated, so that signal demodulation fails, and an excessive direct current offset can influence the normal operation of a mixing or non-mixing system. How to eliminate the dc offset is a major research topic.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a direct current skew calibration circuit for mixer has solved GNSS GSM TD WCDMA LTE communication system, radio frequency front end module electric capacity inductance process deviation's automatic compensation calibration.

The utility model provides a direct current skew calibration circuit for mixer, generate the circuit module including radio frequency front end module, low-noise amplification module, mixing module, transimpedance amplification module, filtering module, analog-to-digital conversion module, algorithm module and reference frequency, radio frequency front end module and low-noise amplification module are connected, low-noise amplification module is connected with the mixing module, transimpedance amplification module is connected with the mixing module, filtering module and transimpedance amplification module are connected, analog-to-digital conversion module is connected with filtering module, algorithm module and filtering module are connected, algorithm module and mixing module are connected, reference frequency generates the circuit module and is connected with the mixing module.

In the above scheme, the low noise amplification module includes one or more LC modules.

In the above scheme, the algorithm module is an LC auto-calibration digital algorithm module.

The utility model has the advantages and the beneficial effects that: the utility model provides a direct current skew calibration circuit for mixer has solved GNSS/GSM TD WCDMA LTE communication system, and the automatic compensation calibration of radio frequency front end module electric capacity inductance technological deviation improves the performance and the yield of chip work, realizes extensive volume production.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of the present invention.

In the figure: 1. the radio frequency front end module 2, the low noise amplification module 3, the mixing module 4, the transimpedance amplification module 5, the filtering module 6, the analog-to-digital conversion module 7, the algorithm module 8 and the reference frequency generation circuit module

Detailed Description

The following description will further describe embodiments of the present invention with reference to the accompanying drawings and examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

As shown in fig. 1, the present invention is a dc offset calibration circuit for a mixer, comprising a radio frequency front end module 1, a low noise amplifier module 2, a mixer module 3, a transimpedance amplifier module 4, a filter module 5, an analog-to-digital conversion module 6, an algorithm module 7, and a reference frequency generation circuit module 8, wherein an output end of the radio frequency front end module 1 is connected to an input end of the low noise amplifier module 2, an output end of the low noise amplifier module 2 is connected to an input end of the mixer module 3, an output end of the mixer module 3 is connected to an input end of the transimpedance amplifier module 4, an output end of the transimpedance amplifier module 4 is connected to an input end of the filter module 5, an output end of the filter module 5 is connected to an input end of the analog-to-digital conversion module 6, an output end of the analog-to-digital conversion module 6 is connected to an input end of the algorithm module 7, and, the reference frequency generating circuit block 8 is connected to the input of the frequency mixing block 3. The algorithm module 7 is an LC auto-calibration digital algorithm module.

Specifically, the low noise amplification module 2 includes one or more LC modules.

The work flow of the technical scheme is as follows: the radio frequency signal input enters the frequency mixing module 3 through the low noise amplification module 2, and the signal generated by the reference frequency generation circuit module 8 enters the frequency mixing module 3 to be mixed, then is transmitted to the transimpedance amplification module 4 to be amplified, then passes through the filtering module 5 to be filtered and the analog-to-digital conversion module, enters the LC automatic calibration digital algorithm to be processed, and then enters the frequency mixing module 3 to be subjected to the next cycle.

The specific principle is as follows:

the reference frequency generation circuit module generates reference frequency VRF and VLO to carry out frequency mixing to generate direct current components (an I channel is effective, a Q channel is 0), analog-to-digital conversion is carried out through A direct current, and then the direct current enters the algorithm module to be processed. Mixing relationships, as follows:

V_RF＝A_RF·cos(ω_LOt)

the process of the automatic calibration algorithm comprises the following steps: the LO _ buffer is opened firstly, then the A direct current output signal value (X) is detected, the A direct current outputs the maximum signal value by repeatedly adjusting the control word of the capacitor array of the control LC, the obtained control word is the final result, and the LO _ buffer is closed after the adjustment is finished.

The utility model discloses a LC automatic calibration circuit, contain calibration route and calibration algorithm, wherein the LC that will be calibrated is in radio frequency front end module low noise amplification module, the core principle produces the direct current offset (be applicable to zero intermediate frequency framework system) through the mixing, baseband filter does not produce the direct current offset in addition (before doing LC automatic calibration, will carry out wave filter direct current offset calibration earlier), the digital quantity of A direct current output direct current offset, through the automatic calibration algorithm, find out the control bit that the output maximum value corresponds, make LC automatic calibration circuit scheme realize.

The utility model has the advantages that:

the utility model discloses a direct current skew calibration circuit for mixer has solved GNSS/GSM TD WCDMA LTE communication system, and the automatic compensation calibration of radio frequency front end module electric capacity inductance technological deviation improves the performance and the yield of chip work, realizes extensive volume production.

The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a direct current offset calibration circuit for mixer, its characterized in that, includes radio frequency front end module, low noise amplifier module, mixing module, transimpedance amplifier module, filtering module, analog-to-digital conversion module, algorithm module and reference frequency generation circuit module, radio frequency front end module is connected with low noise amplifier module, low noise amplifier module is connected with the mixing module, transimpedance amplifier module is connected with the mixing module, filtering module is connected with transimpedance amplifier module, analog-to-digital conversion module is connected with the filtering module, algorithm module is connected with the mixing module, reference frequency generation circuit module is connected with the mixing module.

2. The dc offset calibration circuit for a mixer of claim 1, wherein the low noise amplification module comprises one or more LC modules.

3. The dc offset calibration circuit for a mixer of claim 1, wherein said algorithm module is an LC auto-calibration digital algorithm module.