阅读说明：本技术 一种混频器自动校准系统及方法 (Automatic calibration system and method for frequency mixer ) 是由 李清石 刘强 金长新 于晓艳 于 2019-11-29 设计创作，主要内容包括：本发明公开了一种混频器自动校准系统及方法,属于混频器校准技术领域。本发明的混频器自动校准系统,包括上位机、信号发生器、微波源、混频器和频谱分析仪,上位机中设有混频器自动校准程序,混频器自动校准程序包括直流偏置校准模块和边带校准模块,上位机分别与信号发生器、频谱分析仪相通信,信号发生器与混频器的I端口和Q端口相通信,微波源与混频器的LO端口相通信,混频器的RF端口与频谱分析仪相通信。该发明的混频器自动校准系统能够有效的消除信号泄漏和不需要的频率信号,具有很好的推广应用价值。(The invention discloses an automatic calibration system and method for a frequency mixer, and belongs to the technical field of frequency mixer calibration. The automatic calibration system of the frequency mixer comprises an upper computer, a signal generator, a microwave source, the frequency mixer and a spectrum analyzer, wherein an automatic calibration program of the frequency mixer is arranged in the upper computer, the automatic calibration program of the frequency mixer comprises a direct current offset calibration module and a sideband calibration module, the upper computer is respectively communicated with the signal generator and the spectrum analyzer, the signal generator is communicated with an I port and a Q port of the frequency mixer, the microwave source is communicated with an LO port of the frequency mixer, and an RF port of the frequency mixer is communicated with the spectrum analyzer. The automatic calibration system of the frequency mixer can effectively eliminate signal leakage and unnecessary frequency signals, and has good popularization and application values.)

1. An automatic mixer calibration system, comprising: the frequency spectrum analyzer comprises an upper computer, a signal generator, a microwave source, a frequency mixer and a frequency spectrum analyzer, wherein a frequency mixer automatic calibration program is arranged in the upper computer and comprises a direct current offset calibration module and a sideband calibration module, the upper computer is respectively communicated with the signal generator and the frequency spectrum analyzer, the signal generator is communicated with an I port and a Q port of the frequency mixer, the microwave source is communicated with an LO port of the frequency mixer, and an RF port of the frequency mixer is communicated with the frequency spectrum analyzer.

2. The mixer auto-calibration system of claim 1, wherein: the frequency mixing automatic calibration program controls the signal generator to send two paths of intermediate frequency signals to an I port and a Q port of the frequency mixer, a local oscillation signal generated by the microwave source is input to an LO port of the frequency mixer, the two paths of intermediate frequency signals and the local oscillation signal are subjected to frequency mixing in the frequency mixer, and the frequency mixing signal is output at an RF port of the frequency mixer.

3. The mixer auto-calibration system of claim 2, wherein: the direct current offset calibration module controls the signal generator to adjust two paths of direct current signals input to an I port and a Q port of the mixer.

4. The mixer auto-calibration system of claim 3, wherein: the sideband calibration module controls the signal generator to adjust the amplitude and the phase of two paths of sinusoidal signals input to the I port and the Q port of the mixer.

5. An automatic calibration method for a mixer, comprising: the method is implemented by the automatic calibration system of any one of claims 1 to 4, wherein the automatic calibration program of the mixer controls the signal generator to send two intermediate frequency signals to the I port and the Q port of the mixer, the local oscillator signal generated by the microwave source is input to the LO port of the mixer, the two intermediate frequency signals and the local oscillator signal are mixed in the mixer, the RF signal is output at the RF port of the mixer, the spectrum analyzer measures the signal amplitude at the corresponding frequency of the radio frequency signal, and the automatic calibration program of the mixer obtains the measured value of the spectrum analyzer and processes the measured value to obtain the calibration parameter of the mixer.

6. The method of claim 5, wherein: the DC offset calibration is realized through a DC offset calibration module, and the specific process is as follows:

(1) the direct current offset calibration module controls the signal generator to adjust the amplitude of two paths of direct current signals input to an I port and a Q port of the mixer;

(2) the method comprises the following steps that a spectrum analyzer measures the amplitude of a local oscillation signal from an LO port of a mixer leaked from an RF port of the mixer at the frequency of the local oscillation signal;

(3) the direct current offset calibration module is communicated with the spectrum analyzer to obtain the amplitude of the local oscillator signal;

(4) in the interval with the adjustable direct current offset amplitude, the direct current offset calibration module controls a signal generator to traverse the combination of the amplitudes of the two paths of direct current signals and simultaneously obtains the amplitude of a local oscillation signal measured by the spectrum analyzer;

(5) and the direct current offset calibration module selects the combination of the two paths of direct current signal amplitudes which enables the amplitude of the local oscillator signal to be minimum as a direct current offset calibration parameter for inhibiting local oscillator leakage and stores the direct current offset calibration parameter in the nonvolatile memory.

7. The method of claim 6, wherein: realize the sideband calibration through the sideband calibration module, the concrete process is:

(a) the sideband calibration module controls the signal generator to adjust the amplitude and the phase of two paths of sinusoidal signals input to an I port and a Q port of the mixer;

(b) the spectrum analyzer measures the amplitude of the unwanted sideband signal output by the mixer RF port at the unwanted sideband signal frequency;

(c) the sideband calibration module is communicated with the spectrum analyzer to acquire the amplitude of an unwanted sideband signal;

(d) in the amplitude and phase adjustable range, the sideband calibration module controls the signal generator to traverse the amplitude and phase of two paths of sinusoidal signals input to an I port and a Q port of the mixer, and meanwhile obtains the amplitude of an unwanted sideband signal measured by the spectrum analyzer;

(e) the sideband calibration module selects the combination of the amplitude and the phase of the two paths of sinusoidal signals which enables the amplitude of the unwanted sideband signal to be minimum as a sideband calibration parameter for suppressing image frequency interference and stores the sideband calibration parameter in a nonvolatile memory.

8. The method of automatic calibration of a mixer of claim 7, wherein: under the condition of unchanging setting, the calibration parameters stored into the nonvolatile memory by the mixer automatic calibration program in the mixer calibration process can be used for subsequent mixing of the mixer, and the mixer does not need to be calibrated.

Technical Field

The invention relates to the technical field of mixer calibration, and particularly provides an automatic mixer calibration system and an automatic mixer calibration method.

Background

An ideal mixer can produce a single frequency signal at the output port, but in practice the mixer cannot achieve the ideal state, which can result in signal leakage and the generation of unwanted frequency signals. The signal leakage and the unnecessary frequency signals can be effectively eliminated by calibrating the mixer, and how to efficiently realize the automatic calibration of the mixer is a technical problem to be solved.

Disclosure of Invention

The present invention addresses the above-identified problems by providing an automatic mixer calibration system that effectively eliminates signal leakage and unwanted frequency signals.

It is a further technical task of the present invention to provide a method for automatic calibration of a mixer.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a mixer automatic calibration system, includes host computer, signal generator, microwave source, mixer and spectrum analysis appearance, is equipped with mixer automatic calibration procedure in the host computer, and mixer automatic calibration procedure includes direct current offset calibration module and sideband calibration module, and the host computer communicates with signal generator, spectrum analysis appearance respectively, and signal generator communicates with the I port and the Q port of mixer, and the microwave source communicates with the LO port of mixer, and the RF port of mixer communicates with the spectrum analysis appearance.

Preferably, the mixing auto-calibration program controls the signal generator to send two paths of intermediate frequency signals to an I port and a Q port of the mixer, the local oscillator signal generated by the microwave source is input to an LO port of the mixer, the two paths of intermediate frequency signals are mixed with the local oscillator signal in the mixer, and the mixed signal is output at an RF port of the mixer.

Preferably, the dc offset calibration module controls the signal generator to adjust two dc signals input to the I port and the Q port of the mixer.

Preferably, the sideband calibration module controls the signal generator to adjust the amplitude and the phase of the two paths of sinusoidal signals input to the I port and the Q port of the mixer.

A mixer automatic calibration method is realized through the mixer automatic calibration system, a mixer automatic calibration program controls a signal generator to send two paths of intermediate frequency signals to an I port and a Q port of a mixer, a local oscillator signal generated by a microwave source is input to an LO port of the mixer, the two paths of intermediate frequency signals and the local oscillator signal are mixed in the mixer, a radio frequency signal is output at an RF port of the mixer, a spectrum analyzer measures a signal amplitude value at a frequency corresponding to the radio frequency signal, and the mixer automatic calibration program obtains a measurement value of the spectrum analyzer to process the measurement value to obtain mixer calibration parameters.

Preferably, the dc offset calibration is realized by a dc offset calibration module, and the specific process is as follows:

(1) the direct current offset calibration module controls the signal generator to adjust the amplitude of two paths of direct current signals input to an I port and a Q port of the mixer;

(2) the method comprises the following steps that a spectrum analyzer measures the amplitude of a local oscillation signal from an LO port of a mixer leaked from an RF port of the mixer at the frequency of the local oscillation signal;

(3) the direct current offset calibration module is communicated with the spectrum analyzer to obtain the amplitude of the local oscillator signal;

(4) in the interval with the adjustable direct current offset amplitude, the direct current offset calibration module controls a signal generator to traverse the combination of the amplitudes of the two paths of direct current signals and simultaneously obtains the amplitude of a local oscillation signal measured by the spectrum analyzer;

(5) and the direct current offset calibration module selects the combination of the two paths of direct current signal amplitudes which enables the amplitude of the local oscillator signal to be minimum as a direct current offset calibration parameter for inhibiting local oscillator leakage and stores the direct current offset calibration parameter in the nonvolatile memory.

Preferably, the sideband calibration is realized by a sideband calibration module, and the specific process is as follows:

(a) the sideband calibration module controls the signal generator to adjust the amplitude and the phase of two paths of sinusoidal signals input to an I port and a Q port of the mixer;

(b) the spectrum analyzer measures the amplitude of the unwanted sideband signal output by the mixer RF port at the unwanted sideband signal frequency;

(c) the sideband calibration module is communicated with the spectrum analyzer to acquire the amplitude of an unwanted sideband signal;

(d) in the amplitude and phase adjustable range, the sideband calibration module controls the signal generator to traverse the amplitude and phase of two paths of sinusoidal signals input to an I port and a Q port of the mixer, and meanwhile obtains the amplitude of an unwanted sideband signal measured by the spectrum analyzer;

(e) the sideband calibration module selects the combination of the amplitude and the phase of the two paths of sinusoidal signals which enables the amplitude of the unwanted sideband signal to be minimum as a sideband calibration parameter for suppressing image frequency interference and stores the sideband calibration parameter in a nonvolatile memory.

Preferably, the calibration parameters stored in the non-volatile memory by the auto-calibration program of the mixer during the calibration of the mixer are used for subsequent mixing of the mixer without calibration of the mixer.

Compared with the prior art, the automatic calibration method of the mixer has the following outstanding advantages: the mixer automatic calibration method can effectively eliminate signal leakage and unnecessary frequency signals, calibration parameters obtained by a mixer automatic calibration program in the mixer calibration process can be stored in a nonvolatile memory, and calibration can be omitted in subsequent mixing under the condition that system setting is not changed, so that the mixer automatic calibration method has good popularization and application values.

Drawings

Fig. 1 is a topology diagram of an automatic mixer calibration system according to the present invention.

Detailed Description

The mixer automatic calibration system and method of the present invention will be described in further detail with reference to the accompanying drawings and embodiments.