IQ mixer calibration circuit, calibration method and related device

Abstract

The invention relates to an IQ mixer calibration circuit, a calibration method and a related device, and the first end of a local oscillator of an IQ mixer is connected with the first end of an I-path mixer of the IQ mixer through a first phase shifter; the first end of the local oscillator is connected with the first end of the Q-path mixer of the IQ mixer through the second phase shifter; the second end, connected with the I end of the IQ mixer, of the I-path mixer, the second end, connected with the Q end of the IQ mixer, of the Q-path mixer, the first phase shifter and the second phase shifter are respectively connected to a detection calibration module; and the detection calibration module is used for respectively determining a first phase value of the first phase shifter and a second phase value of the second phase shifter based on a first signal output by the second end of the I-path mixer and a second signal output by the second end of the Q-path mixer. According to the embodiment of the invention, the amplitude and phase imbalance calibration of the IQ mixer can be realized under the condition that a baseband module is not adopted, and the realization complexity is low.

Description

Technical Field

[0001] The present application relates to the technical field of communication equipment, and in particular to an IQ mixer calibration circuit, calibration method, and related devices. Background Art

[0002] Quadrature modulation and demodulation has become the preferred architecture for deploying RF front-ends in applications such as cellular base stations, World Interoperability for Microwave Access (WiMAX), and wireless point-to-point. Quadrature modulation works by modulating two separate signals, I and Q (in-phase and quadrature-phase), using the same carrier frequency. However, the carriers are phase-different because the carrier of signal Q lags behind the carrier of signal I by 90°. After modulation, the signals are added together. Due to the phase difference, the I and Q signals can be separated when the added signals are demodulated. This technology directly modulates the IQ signals output by the digital-to-analog converter onto the radio frequency (RF) carrier. Compared to the superheterodyne architecture, this reduces the intermediate frequency (IF) and filter requirements, significantly simplifying the RF chain. In most scenarios, quadrature modulation and demodulation rely on in-phase and quadrature mixers (IQ mixers). During the modulation process, amplitude and phase imbalance between the IQ output signals is a common problem in IQ mixers. This imbalance directly affects the sideband suppression performance, which in turn increases the error vector magnitude (EVM) at the receiver, thereby worsening the bit error rate.

[0003] Therefore, amplitude and phase calibration or compensation of the IQ mixer's two signals is a necessary measure in practical applications. However, existing technologies typically use a complex baseband module architecture and a certain calibration algorithm to perform imbalance calibration, which is highly complex to implement. Summary of the Invention

[0004] The embodiments of the present application provide an IQ mixer calibration circuit, calibration method, and related devices, which can implement amplitude and phase imbalance calibration of the IQ mixer without using a baseband module, with low implementation complexity and small baseband chip resource usage.

[0005] In a first aspect, an embodiment of the present application provides an IQ mixer calibration circuit, comprising an IQ mixer, a first phase shifter, a second phase shifter, and a detection calibration module;

[0006] A first end of a local oscillator of the IQ mixer is connected to a first end of an I-channel mixer of the IQ mixer via a first phase shifter;

[0007] The first end of the local oscillator is connected to the first end of the Q-channel mixer of the IQ mixer through the second phase shifter;

[0008] The second end of the I-channel mixer connected to the I end of the IQ mixer, the second end of the Q-channel mixer connected to the Q end of the IQ mixer, the first phase shifter, and the second phase shifter are respectively connected to the detection and calibration module;

[0009] The detection and calibration module is used to determine the first phase value of the first phase shifter and the second phase value of the second phase shifter based on the first signal output from the second end of the I mixer and the second signal output from the second end of the Q mixer.

[0010] As can be seen, in the embodiment of the present application, a first phase shifter and a second phase shifter are added to the local oscillator end of the I-channel mixer and the local oscillator end of the Q-channel mixer, respectively. The first phase shifter and the second phase shifter are respectively connected to a detection and calibration module, which is connected to the second end of the I-channel mixer and the second end of the Q-channel mixer. The detection and calibration module can adjust the phase of the local oscillator signal input to the I-channel mixer and / or the Q-channel mixer by adjusting the phase value of the first phase shifter and / or the second phase shifter, and can determine the first phase value of the first phase shifter based on the first signal output from the second end of the I-channel mixer, and / or can determine the second phase value of the second phase shifter based on the second signal output from the second end of the Q-channel mixer. The first phase value and / or the second phase value are used to achieve a phase difference of 90° between the IQ signals of the IQ mixer. In this way, without adding a baseband module, the IQ mixer can realize the phase imbalance calibration of the IQ two-way signal. There is no need for high-speed analog-to-digital conversion / digital-to-analog conversion modules and complex algorithms. The baseband chip resource usage is low, which reduces the implementation complexity.

[0011] In one possible implementation, the first signal is obtained by mixing the third signal and the fourth signal by an I-channel mixer; the third signal is input from the RF end of the IQ mixer, and the fourth signal is input from the local oscillator signal output by the local oscillator after passing through the first phase shifter; the second signal is obtained by mixing the third signal and the fifth signal by a Q-channel mixer; the fifth signal is input from the local oscillator signal output by the local oscillator after passing through the second phase shifter; and the third signal has the same frequency as the fourth signal and the fifth signal.

[0012] In this implementation, signals of the same frequency are input from the local oscillator end and the radio frequency end of the IQ mixer respectively to the I-channel mixer and the Q-channel mixer for mixing, and the output signals of the I-channel mixer and the Q-channel mixer are detected by the detection and calibration module to obtain the relationship between the phase difference of the input signal at the local oscillator end and the radio frequency end and the DC component of the output signal.

[0013] In one possible implementation, the detection and calibration module is specifically configured to:

[0014] adjusting the phase value of the first phase shifter to a first phase value; when the value of the first phase shifter is the first phase value, the value of the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0015] and / or adjusting the value of the second phase shifter to a second phase value; when the value of the second phase shifter is the second phase value, the value of the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0016] In this implementation, the detection and calibration module can adjust the phase value of the first phase shifter so that the value of the DC component of the first signal is the first target value, thereby obtaining the first phase value that needs to be calibrated for the first phase shifter, thereby achieving calibration of the I-channel phase of the IQ mixer; the detection and calibration module can adjust the phase value of the second phase shifter so that the value of the DC component of the second signal is the second target value, thereby obtaining the second phase value that needs to be calibrated for the second phase shifter, thereby achieving calibration of the Q-channel phase of the IQ mixer, and further achieving a phase difference of 90° between the IQ signals of the IQ mixer.

[0017] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0018] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0019] In this implementation, the first value and the second value of the DC component of the first signal are their maximum and minimum values, respectively, and the first value and the second value of the DC component of the second signal are their maximum and minimum values, respectively. The detection and calibration module adjusts the phase value of the first phase shifter so that the phase difference between the third signal and the fourth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the first signal, and then, based on the maximum and minimum values, obtains the first target value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°. The detection and calibration module adjusts the phase value of the second phase shifter so that the phase difference between the third signal and the fifth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the second signal, and then, based on the maximum and minimum values, obtains the second target value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0020] In a possible implementation, the device further includes a first attenuator and / or a second attenuator;

[0021] The second end of the I-channel mixer is connected to the I end through the first attenuator; the second end of the Q-channel mixer is connected to the Q end through the second attenuator; the first attenuator and the second attenuator are respectively connected to the detection and calibration module.

[0022] In this implementation, the detection and calibration module can achieve amplitude balance of the IQ two-way signal of the IQ mixer by adjusting the attenuation value of the first attenuator or the attenuation value of the second attenuator.

[0023] In a possible implementation, the detection and calibration module is further configured to:

[0024] The attenuation value of the first attenuator or the second attenuator is adjusted based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

[0025] In this implementation, the detection calibration module may adjust the attenuation value of the first attenuator or the second attenuator based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal.

[0026] In one possible implementation, the detection and calibration module is specifically configured to:

[0027] Determine an amplitude ratio of two IQ signals of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal and a first value and a second value of a DC component of the second signal;

[0028] determining an adjustment amount of the first attenuator or an adjustment amount of the second attenuator based on the amplitude ratio;

[0029] The attenuation value of the first attenuator is adjusted based on the adjustment amount of the first attenuator; or the attenuation value of the second attenuator is adjusted based on the adjustment amount of the second attenuator.

[0030] In this implementation, the detection and calibration module can determine the amplitude ratio of the IQ two-way signal of the IQ mixer based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal, thereby determining the amplitude imbalance of the IQ two-way signal according to the amplitude ratio, and determining the adjustment amount of the first attenuator or the adjustment amount of the second attenuator in the case of amplitude imbalance, and then adjusting the attenuation value of the corresponding attenuator based on the attenuation amount to achieve amplitude balance of the IQ two-way signal of the IQ mixer.

[0031] In a possible implementation, the second end of the local oscillator is connected to the radio frequency end of the IQ mixer through a switch device.

[0032] In this implementation, the local oscillator is connected to the RF end through a switch device. When the switch is closed, the local oscillator can input a local oscillator signal having the same frequency as the fourth signal and the fifth signal to the RF end.

[0033] In a possible implementation, the third signal is a local oscillator signal input from a local oscillator to a radio frequency terminal of the IQ mixer when the switch device is closed.

[0034] In this implementation, the third signal input by the radio frequency end to the mixer may come from a local oscillator.

[0035] In a second aspect, an embodiment of the present application provides an IQ mixer calibration circuit, comprising an IQ mixer, a third phase shifter, and a detection calibration module;

[0036] A first end of a local oscillator of the IQ mixer is connected to first ends of an I mixer and a Q mixer of the IQ mixer respectively;

[0037] The second end of the local oscillator is connected to the radio frequency end of the IQ mixer through the switch device and the third phase shifter in sequence;

[0038] The second end of the I-channel mixer connected to the I end of the IQ mixer, the second end of the Q-channel mixer connected to the Q end of the IQ mixer, and the third phase shifter are respectively connected to the detection and calibration module;

[0039] The detection and calibration module is used to determine the third phase value and the fourth phase value of the third phase shifter based on the first signal output from the second end of the I mixer and the second signal output from the second end of the Q mixer.

[0040] It can be seen that in the embodiment of the present application, a third phase shifter is added to the RF end of the IQ mixer, and the local oscillator is connected to the RF end through a switch device and the third phase shifter. Then, the signal input to the IQ mixer from the RF end can be provided by the local oscillator. The third phase shifter is connected to the detection and calibration module, and the detection and calibration module is connected to the second end of the I mixer and the second end of the Q mixer. The detection and calibration module can adjust the phase of the RF end signals input to the I mixer and the Q mixer by adjusting the phase value of the third phase shifter, and can determine the third phase value of the third phase shifter based on the first signal output from the second end of the I mixer, and / or can determine the fourth phase value of the third phase shifter based on the second signal output from the second end of the Q mixer. The third phase value and / or the fourth phase value are used to achieve a phase difference of 90° between the IQ two-way signals of the IQ mixer. In this way, without adding a baseband module, the IQ mixer can realize the phase imbalance calibration of the IQ two-way signal. There is no need for high-speed analog-to-digital conversion / digital-to-analog conversion modules and complex algorithms. The baseband chip resource usage is low, which reduces the implementation complexity.

[0041] In one possible implementation, the first signal is obtained by mixing the third signal and the fourth signal by an I-channel mixer; the third signal is obtained by inputting a local oscillator signal from a local oscillator to a radio frequency terminal of the IQ mixer when the switch device is closed and then passing through a third phase shifter; and the fourth signal is input from the local oscillator to the I-channel mixer;

[0042] The second signal is obtained by mixing the third signal and the fifth signal by a Q-channel mixer; the fifth signal is input to the Q-channel mixer by a local oscillator; the third signal has the same frequency as the fourth signal and the fifth signal.

[0043] In this implementation, signals of the same frequency are input from the local oscillator and the RF side of the IQ mixer, respectively, to the I mixer and Q mixer for mixing. A detection and calibration module then detects the output signals of the I mixer and Q mixer, thereby determining the relationship between the phase difference between the input signals at the local oscillator and RF sides and the DC component of the output signals. The local oscillator is sequentially connected to the RF side via a switch device and a third phase shifter. When the switch is closed, the local oscillator can input a local oscillator signal with the same frequency as the fourth and fifth signals to the RF side. This means that the third signal input from the RF side to the mixer can originate from the local oscillator.

[0044] In one possible implementation, the detection and calibration module is specifically configured to:

[0045] adjusting the value of the third phase shifter to a third phase value; when the value of the third phase shifter is the third phase value, the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0046] and / or adjusting the value of the third phase shifter to a fourth phase value; when the value of the third phase shifter is the fourth phase value, the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0047] In this implementation, the detection and calibration module can adjust the phase value of the third phase shifter so that the value of the DC component of the first signal is a first target value, thereby obtaining a third phase value of the third phase shifter, and thus calibrating the phase of the I path of the IQ mixer based on the third phase value; the detection and calibration module can adjust the phase value of the third phase shifter so that the value of the DC component of the second signal is a second target value, thereby obtaining a fourth phase value of the third phase shifter, and thus calibrating the phase of the Q path of the IQ mixer based on the fourth phase value, thereby achieving a phase difference of 90° between the IQ two-path signals of the IQ mixer.

[0048] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0049] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0050] In this implementation, the detection and calibration module adjusts the phase value of the third phase shifter so that the phase difference between the third signal and the fourth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the first signal. Based on the maximum and minimum values, a first target value of the DC component of the first signal is obtained when the phase difference between the third signal and the fourth signal is 90°. The detection and calibration module adjusts the phase value of the third phase shifter so that the phase difference between the third signal and the fifth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the second signal. Based on the maximum and minimum values, a second target value of the DC component of the second signal is obtained when the phase difference between the third signal and the fifth signal is 90°.

[0051] In a possible implementation, a fourth phase shifter and / or a fifth phase shifter are further included;

[0052] The second end of the I mixer is connected to the I end through the fourth phase shifter; the second end of the Q mixer is connected to the Q end through the fifth phase shifter; the fourth phase shifter and the fifth phase shifter are respectively connected to the detection and calibration module.

[0053] In this implementation, the IQ mixer calibration circuit also includes a fourth phase shifter and / or a fifth phase shifter, and the fourth phase shifter and the fifth phase shifter are respectively connected to the detection calibration module. The detection calibration module can adjust the phase value of the fourth phase shifter and / or the fifth phase shifter based on the third phase value and the fourth phase value of the third phase shifter to achieve a phase difference of 90° between the IQ two signals of the IQ mixer.

[0054] In a possible implementation, the detection and calibration module is further configured to adjust the phase value of the fourth phase shifter to the third phase value; and adjust the phase value of the fifth phase shifter to the fourth phase value.

[0055] In this implementation, when the IQ mixer calibration circuit includes PH4 and PH5, the detection calibration module can adjust the phase value of the fourth phase shifter to the third phase value, and adjust the phase value of the fifth phase shifter to the fourth phase value, so as to achieve a phase difference of 90° between the IQ two signals of the IQ mixer.

[0056] In a possible implementation, the detection and calibration module is further configured to adjust the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on the difference between the third phase value and the fourth phase value.

[0057] In this implementation, when the IQ mixer calibration circuit only includes PH4 or PH5, the detection calibration module can adjust the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on the difference between the third phase value and the fourth phase value to achieve a phase difference of 90° between the IQ two signals of the IQ mixer.

[0058] In a possible implementation, a third attenuator and / or a fourth attenuator are further included;

[0059] The second end of the I-channel mixer is connected to the I end through the fourth phase shifter and the third attenuator in sequence; the second end of the Q-channel mixer is connected to the Q end through the fifth phase shifter and the fourth attenuator in sequence; the third attenuator and the fourth attenuator are respectively connected to the detection and calibration module.

[0060] In this implementation, the detection and calibration module can achieve amplitude balance of the IQ two-path signals of the IQ mixer by adjusting the attenuation value of the third attenuator or the attenuation value of the fourth attenuator.

[0061] In a possible implementation, the detection and calibration module is further configured to adjust the attenuation value of the third attenuator or the fourth attenuator based on the first and second values ​​of the DC component of the first signal and the first and second values ​​of the DC component of the second signal.

[0062] In this implementation, the detection and calibration module can adjust the attenuation value of the third attenuator or the attenuation value of the fourth attenuator based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal. By adjusting the attenuation value of the third attenuator or the attenuation value of the fourth attenuator, the amplitude balance of the IQ two signals of the IQ mixer can be achieved.

[0063] In one possible implementation, the detection and calibration module is specifically configured to:

[0064] Determine an amplitude ratio of two IQ signals of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal and a first value and a second value of a DC component of the second signal;

[0065] determining an adjustment amount of the third attenuator or an adjustment amount of the fourth attenuator based on the amplitude ratio;

[0066] The attenuation value of the third attenuator is adjusted based on the adjustment amount of the third attenuator; or the attenuation value of the fourth attenuator is adjusted based on the adjustment amount of the fourth attenuator.

[0067] In this implementation, the detection and calibration module can determine the amplitude ratio of the IQ two-way signal of the IQ mixer based on the maximum value and minimum value of the DC component of the first signal and the maximum value and minimum value of the DC component of the second signal, thereby determining the amplitude imbalance of the IQ two-way signal according to the amplitude ratio, and determining the adjustment amount of the third attenuator or the adjustment amount of the fourth attenuator in the case of amplitude imbalance, and then adjusting the attenuation value of the corresponding attenuator based on the attenuation amount to achieve amplitude balance of the IQ two-way signal of the IQ mixer.

[0068] In a third aspect, an embodiment of the present application provides a calibration method, which is applied to the IQ mixer calibration circuit described in any one embodiment of the first aspect; the method includes:

[0069] The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer;

[0070] The local oscillator inputs a fourth signal to the I-channel mixer through a first phase shifter, and inputs a fifth signal to the Q-channel mixer through a second phase shifter; the third signal has the same frequency as the fourth signal and the fifth signal;

[0071] The first mixer mixes the third signal and the fourth signal and then outputs the first signal from the second end;

[0072] The Q-channel mixer mixes the third signal and the fifth signal and then outputs the second signal from the second end;

[0073] The detection calibration module determines a first phase value of the first phase shifter based on the first signal and / or determines a second phase value of the second phase shifter based on the second signal.

[0074] In one possible implementation, determining a first phase value of a first phase shifter based on the first signal includes:

[0075] The detection and calibration module adjusts the phase value of the first phase shifter to a first phase value; when the value of the first phase shifter is the first phase value, the value of the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0076] Determining a second phase value of a second phase shifter based on the second signal includes:

[0077] The detection and calibration module adjusts the value of the second phase shifter to a second phase value; when the value of the second phase shifter is the second phase value, the value of the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0078] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0079] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0080] In a possible implementation, the method further includes:

[0081] The detection calibration module adjusts the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

[0082] In one possible implementation, adjusting the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes:

[0083] The detection and calibration module determines an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal;

[0084] The detection and calibration module determines an adjustment amount of the first attenuator or an adjustment amount of the second attenuator based on the amplitude ratio;

[0085] The detection and calibration module adjusts the attenuation value of the first attenuator based on the adjustment amount of the first attenuator; or adjusts the attenuation value of the second attenuator based on the adjustment amount of the second attenuator.

[0086] In a possible implementation, the third signal is a local oscillator signal input from a local oscillator to a radio frequency terminal of the IQ mixer when the switch device is closed.

[0087] It should be understood that since the method embodiment and the circuit embodiment are different presentation forms of the same technical concept, the content of the first aspect of the embodiment of the present application should be synchronously adapted to the third aspect of the embodiment of the present application, and can achieve the same or similar beneficial effects, and will not be repeated here.

[0088] In a fourth aspect, an embodiment of the present application provides a calibration method, which is applied to the IQ mixer calibration circuit described in any one embodiment of the second aspect; the method includes:

[0089] The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer; the third signal is obtained by a local oscillator signal input to the radio frequency end of the IQ mixer by a local oscillator when the switch device is closed and then passing through a third phase shifter;

[0090] The local oscillator inputs a fourth signal to the I-channel mixer and a fifth signal to the Q-channel mixer; the third signal has the same frequency as the fourth signal and the fifth signal;

[0091] The first mixer mixes the third signal and the fourth signal and then outputs the first signal from the second end;

[0092] The Q-channel mixer mixes the third signal and the fifth signal and then outputs the second signal from the second end;

[0093] The detection and calibration module determines a third phase value of the third phase shifter based on the first signal and / or determines a fourth phase value of the third phase shifter based on the second signal.

[0094] In one possible implementation, determining a third phase value of a third phase shifter based on the first signal includes:

[0095] The detection and calibration module adjusts the value of the third phase shifter to a third phase value; when the value of the third phase shifter is the third phase value, the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0096] Determining a fourth phase value of a third phase shifter based on the second signal includes:

[0097] The detection and calibration module adjusts the value of the third phase shifter to a fourth phase value; when the value of the third phase shifter is the fourth phase value, the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0098] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0099] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0100] In a possible implementation, the method further includes:

[0101] The detection and calibration module adjusts the phase value of the fourth phase shifter to the third phase value, and / or adjusts the phase value of the fifth phase shifter to the fourth phase value.

[0102] In a possible implementation, the method further includes:

[0103] The detection calibration module adjusts the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on the difference between the third phase value and the fourth phase value.

[0104] In a possible implementation, the method further includes:

[0105] The detection calibration module adjusts the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

[0106] In one possible implementation, adjusting the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes:

[0107] Determine an amplitude ratio of two IQ signals of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal and a first value and a second value of a DC component of the second signal;

[0108] determining an adjustment amount of the third attenuator or an adjustment amount of the fourth attenuator based on the amplitude ratio;

[0109] The attenuation value of the third attenuator is adjusted based on the adjustment amount of the third attenuator; or the attenuation value of the fourth attenuator is adjusted based on the adjustment amount of the fourth attenuator.

[0110] It should be understood that since the method embodiment and the circuit embodiment are different presentation forms of the same technical concept, the content of the second aspect of the embodiment of the present application should be synchronously adapted to the fourth aspect of the embodiment of the present application, and can achieve the same or similar beneficial effects, and will not be repeated here.

[0111] In a fifth aspect, an embodiment of the present application provides a communication device, comprising the IQ mixer calibration circuit as described in any one of the embodiments in the first aspect above; or comprising the IQ mixer calibration circuit as described in any one of the embodiments in the second aspect above.

[0112] In a sixth aspect, an embodiment of the present application provides a communication device, comprising a processor, a memory, a communication device as described in the fifth aspect above, and one or more programs, wherein the one or more programs are stored in the memory and configured to cooperate with the communication device to achieve communication when executed by the processor. The communication device may be a terminal device, an access network device, etc. The terminal device includes but is not limited to a user device, a mobile terminal device, a user terminal device, a wireless electronic device, a vehicle-mounted device, and a wearable device; the access network device may include various forms of base stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0113] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0114] Figure 1 Schematic diagram of the circuit structure of an IQ mixer;

[0115] Figure 2 A schematic diagram of a calibration circuit for an IQ mixer provided in the related art;

[0116] Figure 3 A schematic diagram of another IQ mixer calibration circuit provided in the related art;

[0117] Figure 4 A schematic diagram of frequency mixing using field effect transistors;

[0118] Figure 5 A schematic diagram of an equivalent circuit for implementing frequency mixing using a field effect transistor;

[0119] Figure 6 is a schematic diagram of the relationship between current and signal phase difference;

[0120] Figure 7AA schematic diagram of a radio frequency transmitter architecture for orthogonal modulation provided in an embodiment of the present application;

[0121] Figure 7B A schematic diagram of a radio frequency receiver architecture for orthogonal demodulation provided in an embodiment of the present application;

[0122] Figure 8 A schematic diagram of the structure of an IQ mixer calibration circuit provided in an embodiment of the present application;

[0123] Figure 9 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0124] Figure 10 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0125] Figure 11 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0126] Figure 12 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0127] Figure 13 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0128] Figure 14 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0129] Figure 15 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0130] Figure 16 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0131] Figure 17 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0132] Figure 18 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0133] Figure 19 A schematic structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application;

[0134] Figure 20 A flow chart of a calibration method provided in an embodiment of the present application;

[0135] Figure 21 A schematic diagram of another calibration method provided in an embodiment of the present application;

[0136] Figure 22 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0137] Figure 23 A schematic diagram of the structure of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0138] The terms "first," "second," "third," and "fourth," etc., in the specification and claims of this application and the accompanying drawings are used to distinguish different objects, not to describe a specific order. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0139] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0140] As used in this specification, the terms "component", "module", "system", etc. are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program and / or a computer. By way of illustration, both an application running on a terminal device and a terminal device can be a component. One or more components can reside in a process and / or an execution thread, and a component can be located on a computer and / or distributed between two or more computers. In addition, these components can be executed from various computer-readable media having various data structures stored thereon. Components can communicate, for example, through local and / or remote processes based on signals having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system and / or a network, such as the Internet interacting with other systems via signals).

[0141] First, a brief introduction to the relevant terms and related technical background in this application is given to facilitate understanding by those skilled in the art.

[0142] Local Oscillation: Local Oscillation, Lo;

[0143] Field Effect Transistor: Field Effect Transistor, FET;

[0144] Phaser: Phaser, PH;

[0145] See Figure 1 , Figure 1 Schematic diagram of the circuit structure of an IQ mixer, such as Figure 1 As shown, the IQ mixer includes an RF terminal, a Lo terminal, and an intermediate frequency (IF) terminal. The IF terminal includes an I mixer and a Q mixer. The first terminal of the I mixer is connected to the first terminal of the Lo terminal, the second terminal of the I mixer is connected to the I terminal, and the third terminal of the I mixer is connected to the RF terminal. The first terminal of the Q mixer is connected to the first terminal of the Lo terminal, the second terminal of the Q mixer is connected to the Q terminal, and the third terminal of the Q mixer is connected to the RF terminal. The I and Q terminals are typically connected to an analog-to-digital converter (ADC) or a digital-to-analog converter (DAC). Depending on the application scenario of modulation or demodulation, the output terminals of the two IF mixers will be different. For example, in quadrature modulation, the IF output terminals are the third terminals of the I mixer and the third terminals of the Q mixer, respectively; in quadrature demodulation, the IF output terminals are the second terminals of the I mixer and the second terminals of the Q mixer, respectively. The Lo terminal provides the local oscillator signal, which is split into two paths. One path is directly used as the LO input signal for the I mixer, while the other path is used as the LO input signal for the Q mixer after a 90° phase shift. The RF terminal provides input signals to both mixers or transmits the summed IQ output signals.

[0146] Among the existing solutions in the industry, one of the related technologies is Figure 2 As shown, the quadrature modulated output signal is coupled from the IQ mixer output and fed into the envelope detection module. The signal envelope is detected and then sent to the ADC for sampling. An imbalance estimation algorithm then estimates the IQ imbalance, which is then routed to the imbalance compensation module for IQ imbalance correction. This technology requires a separate feedback channel (including envelope detection and a wideband ADC) and a complex imbalance estimation algorithm. Baseband modules such as the ADC consume significant baseband chip resources, and the imbalance estimation algorithm requires multiple iterations, making the overall calibration implementation complex.

[0147] The second related technology is Figure 3As shown, the quadrature modulated output signal is coupled from the IQ mixer output and fed into the receive channel. After being sampled by the ADC, the signal entering the receive channel is used to estimate IQ imbalance using an imbalance estimation algorithm. This is then configured in the imbalance compensation module to correct IQ imbalance. This solution requires coordination with the receive channel, employing a joint transmit and receive evaluation approach, which consumes significant baseband chip resources. Furthermore, the imbalance estimation algorithm is relatively complex and requires multiple iterations. Furthermore, the quadrature modulation front end is integrated with the baseband chip, and replacing the baseband module requires re-calibration logic, which increases implementation complexity.

[0148] It should be understood that common mixers use FET-based variable resistors to achieve mixing, and the implementation principle is as follows: Figure 4 As shown, it can be used to mix the input signals of the Lo terminal and the RF terminal, or to mix the input signals of the Lo terminal and the IF terminal. The matching network is usually used to ensure the impedance matching between the various parts. When the FET is equivalent to a nonlinear resistor, Figure 4 Equivalent to Figure 5 The circuit shown, Figure 5 As shown, the circuit includes a local oscillator voltage source v a , RF (or IF) voltage source v b , the source impedance R that generates the excitation signal S , load impedance R L and nonlinear resistors.

[0149] Assume that the relationship between the voltage and current of the nonlinear resistor satisfies Formula 1:

[0150]

[0151] Where i is the current on the nonlinear resistor, v is the voltage on the nonlinear resistor, and a n is the coefficient representing the device characteristics, and k is the highest degree of the polynomial.

[0152] The total equivalent voltage source of the loop satisfies Formula 2: v1=V a cos(ω a t+ψ a )+V b cos(ω b t+ψ b )

[0153] Among them, v a =V a cos(ω a t+ψ a ), v b =V b cos(ω b t+ψ b ). V ais the amplitude of the local oscillator voltage source, V b is the amplitude of the RF (or IF) voltage source, v1 is the voltage value of the total equivalent voltage source of the loop, ω is the angular frequency, and ψ is the phase. Substituting formula 2 into formula 1, the current value of each frequency component can be obtained:

[0154]

[0155] If ω a =ω b , then the DC component of i It can be seen that v a and v b When it is a same frequency signal, the DC component i DC With v a and v b The phase difference is related to Figure 6 Given v a 、v b The relationship between the current and the phase difference. Based on this principle, we can detect the DC Get v a and v b Phase information, at the same time, the DC component i DC With v a 、v b The amplitude V a 、V b Then, for the IQ mixer that is commonly used for up and down conversion, in the calibration mode, use the same frequency signal to send it to the local oscillator end and the RF end of the mixer respectively, and detect its DC output in the IQ two channels respectively. By adjusting the phase shifter at the local oscillator end or the RF end, the corresponding relationship between the DC output and the signal phase can be obtained, and the corresponding relationship between the DC output and the signal phase can be obtained by detecting i DC By obtaining the amplitude information of the IQ mixer, the phase difference between the two IQ signals can be determined based on the amplitude information. Based on the detected amplitude and phase information, the imbalance compensation or calibration of the two IQ output signals can be performed.

[0156] In order to overcome the deficiencies of the prior art, the present invention provides an IQ mixer calibration circuit and a corresponding calibration method. The IQ mixer calibration circuit and the calibration method can be applied to Figure 7A The RF transmitter architecture for quadrature modulation shown in FIG. Figure 7B The RF receiver architecture for quadrature demodulation shown uses IQ mixers for both modulation and demodulation. This makes it suitable for the RF transceiver front end, and eliminates the need for joint calibration between the transmitter and receiver.

[0157] The technical solution provided in this application is introduced in detail below in conjunction with specific implementation methods.

[0158] See Figure 8 , Figure 8 A schematic diagram of the structure of an IQ mixer calibration circuit provided in an embodiment of the present application is shown in FIG. Figure 8 As shown, the system includes an IQ mixer, a first phase shifter PH1, a second phase shifter PH2, and a detection and calibration module. The first end of the IQ mixer's Lo is connected to the first end of the I mixer of the IQ mixer via PH1; the first end of the Lo is connected to the first end of the Q mixer of the IQ mixer via PH2; the second end of the I mixer connected to the I end of the IQ mixer, the second end of the Q mixer connected to the Q end of the IQ mixer, the first phase shifter, and the second phase shifter are respectively connected to the detection and calibration module. The detection and calibration module is configured to detect the DC component of the first signal S1 output from the second end of the I mixer and the second signal S2 output from the second end of the Q mixer, and to determine the first phase value of PH1 and the second phase value of PH2 based on S1 and S2, respectively. The first phase value of PH1 and the second phase value of PH2 are used to achieve a 90° phase difference between the IQ mixer's IQ signals, i.e., to perform phase imbalance calibration on the IQ signals. Among them, the first phase value refers to the target value that PH1 needs to be calibrated to, for example: if the first phase value is x1, then the phase value of PH1 needs to be adjusted to x1; the second phase value refers to the target value that PH2 needs to be calibrated to, for example: if the second phase value is x2, then the phase value of PH2 needs to be adjusted to x2.

[0159] For example, Figure 9 As shown, the RF terminal of the IQ mixer inputs a third signal S3 to the I and Q mixers, and Lo outputs a local oscillator signal S. S is then split into two signals: one local oscillator signal passes through PH1 and inputs a fourth signal S4 to the I mixer, while the other local oscillator signal passes through PH2 and inputs a fifth signal S5 to the Q mixer. The I mixer mixes S3 and S4 and outputs S1 from its second terminal, while the Q mixer mixes S3 and S5 and outputs S2 from its second terminal. S3 has the same frequency as S4 and S5.

[0160] In this implementation, signals of the same frequency are input from the Lo and RF ends of the IQ mixer to the I mixer and Q mixer for mixing, and the detection and calibration module detects the output signals of the I mixer and Q mixer to obtain the relationship between the phase difference between the input signals at the Lo and RF ends and the DC component of the output signal.

[0161] Where S3 is represented by V a cos(ωt+ψ0), express S4 as V b cos(ωt+ψ1), then the DC component (current or voltage) of S1 can be expressed as: ∝V a V bcos(ψ0-ψ1), ∝ represents the difference between the actual DC component of S1 and V a V b It can be seen that the amplitude of S1 is related to the phase difference ψ0-ψ1 between S3 and S4. When ψ0-ψ1=0°, the DC component of S1 has a maximum value v1max; when ψ0-ψ1=180°, the DC component of S1 has a minimum value v1min; when ψ0-ψ1=90°, the DC component value of S1 is (v1max+v1min) / 2, and the DC component value of S1 is related to the amplitude V of S1. a V b Based on this, the detection and calibration module can adjust the phase value of PH1 and detect the DC component of S1 to obtain the phase value of PH1 when the phase difference between S3 and S4 is 90°. Similarly, the detection and calibration module can adjust the phase value of PH2 and detect the DC component of S2 to obtain the phase value of PH2 when the phase difference between S3 and S5 is 90°.

[0162] Specifically, the detection and calibration module adjusts the phase value of PH1 so that the phase difference between S3 and S4 is 0°. At this time, the first value of the DC component of S1 (i.e., the maximum value v1max) is detected. The phase value of PH1 is adjusted so that the phase difference between S3 and S4 is 180°. At this time, the second value of the DC component of S1 (i.e., the minimum value v1min) is detected. Similarly, the detection and calibration module adjusts the phase value of PH2 so that the phase difference between S3 and S5 is 0°. At this time, the first value of the DC component of S2 (i.e., the maximum value v2max) is detected. The phase value of PH2 is adjusted so that the phase difference between S3 and S5 is 180°. At this time, the second value of the DC component of S2 (i.e., the minimum value v2min) is detected. The detection and calibration module can determine the first target value of the DC component of S1 when the phase difference between S3 and S4 is 90° based on the first value and second value of the DC component of S1, that is, (v1max+v1min) / 2, that is, the first target value is the value of the DC component of S1 when the phase difference between S3 and S4 is 90°; and / or based on the first value and second value of the DC component of S2, can determine the second target value of the DC component of S2 when the phase difference between S3 and S5 is 90°, that is, (v2max+v2min) / 2, that is, the second target value is the value of the DC component of S2 when the phase difference between S3 and S5 is 90°.

[0163] In this implementation, the detection and calibration module adjusts the phase value of the first phase shifter so that the phase difference between the third signal and the fourth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the first signal. Based on the maximum and minimum values, a first target value of the DC component of the first signal is obtained when the phase difference between the third signal and the fourth signal is 90°. The detection and calibration module adjusts the phase value of the second phase shifter so that the phase difference between the third signal and the fifth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the second signal. Based on the maximum and minimum values, a second target value of the DC component of the second signal is obtained when the phase difference between the third signal and the fifth signal is 90°.

[0164] Exemplarily, when the detection and calibration module obtains (v1max+v1min) / 2, it adjusts the phase value of PH1 so that the value of the DC component of S1 is (v1max+v1min) / 2, and records the phase value of PH1 at this time as the first phase value. In this case, it can be obtained that the phase difference between S3 and S4 is 90°. And / or when the detection and calibration module obtains (v2max+v2min) / 2, it adjusts the phase value of PH2 so that the value of the DC component of S2 is (v2max+v2min) / 2, and records the phase value of PH2 at this time as the second phase value. In this case, it can be obtained that the phase difference between S3 and S5 is 90°. Exemplarily, when the detection and calibration module determines the first phase value, it adjusts the phase value of PH1 to the first phase value. And / or when the detection and calibration module determines the second phase value, it adjusts the phase value of PH2 to the second phase value. Alternatively, the detection and calibration module adjusts the phase value of PH1 or PH2 based on the difference between the first phase value and the second phase value.

[0165] In this implementation, the detection and calibration module can adjust the phase value of the first phase shifter so that the value of the DC component of the first signal is the first target value, thereby obtaining the first phase value that needs to be calibrated for the first phase shifter, thereby achieving calibration of the I-channel phase of the IQ mixer; the detection and calibration module can adjust the phase value of the second phase shifter so that the value of the DC component of the second signal is the second target value, thereby obtaining the second phase value that needs to be calibrated for the second phase shifter, thereby achieving calibration of the Q-channel phase of the IQ mixer, and further achieving a phase difference of 90° between the IQ signals of the IQ mixer.

[0166] For example, Figure 10As shown, the IQ mixer calibration circuit further includes a first attenuator ATT1 and / or a second attenuator ATT2. The second end of the I mixer is connected to the I terminal via ATT1, and / or the second end of the Q mixer is connected to the Q terminal via ATT2. ATT1 and ATT2 are respectively connected to a detection and calibration module. The detection and calibration module can adjust the attenuation value of ATT1 or ATT2 based on the first and second values ​​of the DC component of S1 and the first and second values ​​of the DC component of S2.

[0167] In this implementation, the detection and calibration module can adjust the attenuation value of the first attenuator or the attenuation value of the second attenuator based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal. By adjusting the attenuation value of the first attenuator or the attenuation value of the second attenuator, the amplitude balance of the IQ two signals of the IQ mixer can be achieved.

[0168] Specifically, the detection and calibration module determines the amplitude ratio of the IQ mixer IQ signals based on the first and second values ​​of the DC component of S1 and the first and second values ​​of the DC component of S2. The amplitude ratio satisfies the following relationship:

[0169] X=│(v1max-v1min) / (v2max-v2min)│

[0170] Where X is the amplitude ratio of the IQ signals in the IQ mixer. The detection and calibration module determines the adjustment amount for ATT1 or ATT2 based on the amplitude ratio. If X is greater than 1, the adjustment amount for ATT1 is determined to be 20*log(X); if X is less than 1, the adjustment amount for ATT2 is determined to be 20*log(X). The attenuation value of ATT1 is adjusted based on the adjustment amount of ATT1, or the attenuation value of ATT2 is adjusted based on the adjustment amount of ATT2. When the IQ mixer includes ATT1 and ATT2, when determining the adjustment amount for ATT1, the attenuation value of ATT1 is increased by 20*log(X) to attenuate the amplitude of S1 by 20*log(X); when determining the adjustment amount for ATT2, the attenuation value of ATT2 is increased by 20*log(X) to attenuate the amplitude of S2 by 20*log(X). When the IQ mixer only includes ATT1, when determining the adjustment amount of ATT1, the attenuation value of ATT1 is increased by 20*log(X) to attenuate the amplitude of S1 by 20*log(X); when determining the adjustment amount of ATT2, the attenuation value of ATT1 is decreased by 20*log(X) to increase the amplitude of S1 by 20*log(X). When the IQ mixer only includes ATT2, when determining the adjustment amount of ATT1, the attenuation value of ATT2 is decreased by 20*log(X) to increase the amplitude of S2 by 20*log(X); when determining the adjustment amount of ATT2, the attenuation value of ATT2 is increased by 20*log(X) to decrease the amplitude of S2 by 20*log(X).

[0171] In this implementation, the detection and calibration module can determine the amplitude ratio of the IQ two-way signal of the IQ mixer based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal, thereby determining the amplitude imbalance of the IQ two-way signal according to the amplitude ratio, and determining the adjustment amount of the first attenuator or the adjustment amount of the second attenuator in the case of amplitude imbalance, and then adjusting the attenuation value of the corresponding attenuator based on the attenuation amount to achieve amplitude balance of the IQ two-way signal of the IQ mixer.

[0172] For example, Figure 11 As shown, the second terminal of the IQ mixer's Lo is also connected to the IQ mixer's RF terminal via a switch. S3 represents the local oscillator signal input from the Lo to the IQ mixer's RF terminal when the switch (SW) is closed. In calibration mode, with SW closed, the local oscillator signal output from the Lo is transmitted through the SW to the RF terminal, and then output from the RF terminal.

[0173] In this implementation, the local oscillator is connected to the RF end through a switching device. When the switch condition is closed, the local oscillator can input a local oscillator signal with the same frequency as the fourth signal and the fifth signal to the RF end, that is, the third signal input by the RF end to the mixer can come from the local oscillator.

[0174] As can be seen, in the embodiments of the present application, a first phase shifter and a second phase shifter are added to the local oscillator end of the I-channel mixer and the local oscillator end of the Q-channel mixer, respectively. The first phase shifter and the second phase shifter are connected to a detection and calibration module, respectively, which is connected to the second end of the I-channel mixer and the second end of the Q-channel mixer. The detection and calibration module can adjust the phase of the local oscillator signal input to the I-channel mixer and / or the Q-channel mixer by adjusting the phase value of the first phase shifter and / or the second phase shifter. The first phase value of the first phase shifter can be determined based on the first signal output from the second end of the I-channel mixer, and / or the second phase value of the second phase shifter can be determined based on the second signal output from the second end of the Q-channel mixer. The first phase value and / or the second phase value are used to achieve a 90° phase difference between the IQ mixer's IQ signals. In this way, phase imbalance calibration of the IQ signals can be achieved by the IQ mixer without adding a baseband module. This eliminates the need for high-speed ADC / DAC modules and complex algorithms, reduces baseband chip resource usage, and reduces implementation complexity.

[0175] See Figure 12 , Figure 12 This is a structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application, such as Figure 12 As shown, the system includes an IQ mixer, a third phase shifter PH3, and a detection and calibration module. The first end of the IQ mixer's Lo is connected to the first ends of the I and Q mixers of the IQ mixer, respectively. The second end of the Lo is connected to the RF end of the IQ mixer via a switch device SW and PH3, in sequence. The second end of the I mixer connected to the I end of the IQ mixer, the second end of the Q mixer connected to the Q end of the IQ mixer, and PH3 are respectively connected to the detection and calibration module. The detection and calibration module is configured to detect the DC component of the first signal S1 output from the second end of the I mixer and the second signal S2 output from the second end of the Q mixer, and to determine the third and fourth phase values ​​of PH3 based on S1 and S2, respectively. The third and fourth phase values ​​of PH3 are used to achieve a 90° phase difference between the IQ mixer's IQ signals, i.e., to perform phase imbalance calibration on the IQ signals. Among them, the third phase value refers to the value by which the phase of the I-channel signal of the IQ mixer needs to be adjusted. For example, if the third phase value is x3, the phase of the I-channel signal needs to be adjusted by x3. The fourth phase value refers to the value by which the phase of the Q-channel signal of the IQ mixer needs to be adjusted. For example, if the third phase value is x4, the phase of the Q-channel signal needs to be adjusted by x4.

[0176] For example, Figure 13 As shown, when SW is closed, the local oscillator signal input from the IQ mixer's Lo to the RF terminal passes through PH3 and then is input to the RF terminal, where the RF terminal outputs a third signal S3. That is, S3 is the local oscillator signal input from the Lo to the RF terminal of the IQ mixer when the switch is closed, after passing through PH3. Lo outputs the local oscillator signal S, which is split into two signals: one local oscillator signal inputs the fourth signal S4 to the I mixer, and the other local oscillator signal inputs the fifth signal S5 to the Q mixer. The I mixer mixes S3 and S4 and outputs S1 from its second terminal, while the Q mixer mixes S3 and S5 and outputs S2 from its second terminal. S3 has the same frequency as S4 and S5.

[0177] It should be noted that, in the embodiment of the present application, S3, S4, and S5 are used to distinguish the difference between the input and output terminals, rather than to distinguish the difference in the amplitude, phase, and other characteristics of the signal itself. For example, the signal input from Lo to the I-channel mixer is all S4, although Figure 9 In the embodiment shown, the signal Lo input to the I-channel mixer passes through PH1.

[0178] In this implementation, signals of the same frequency are input from the local oscillator and the RF side of the IQ mixer, respectively, to the I mixer and Q mixer for mixing. A detection and calibration module then detects the output signals of the I mixer and Q mixer, thereby determining the relationship between the phase difference between the input signals at the local oscillator and RF sides and the DC component of the output signals. The local oscillator is sequentially connected to the RF side via a switch device and a third phase shifter. When the switch is closed, the local oscillator can input a local oscillator signal with the same frequency as the fourth and fifth signals to the RF side. This means that the third signal input from the RF side to the mixer can originate from the local oscillator.

[0179] Where S3 is represented by V a cos(ωt+ψ0), express S4 as V b cos(ωt+ψ1), then the DC component (current or voltage) of S1 can be expressed as: ∝V a V b cos(ψ0-ψ1), ∝ represents the difference between the actual DC component of S1 and V a V b It can be seen that the amplitude of S1 is related to the phase difference ψ0-ψ1 between S3 and S4. When ψ0-ψ1=0°, the DC component of S1 has a maximum value v1max; when ψ0-ψ1=180°, the DC component of S1 has a minimum value v1min; when ψ0-ψ1=90°, the DC component value of S1 is (v1max+v1min) / 2, and the DC component value of S1 is related to the amplitude V of S1.a V b Based on this, the detection and calibration module can adjust the phase value of PH3 and detect the DC component of S1 to obtain the phase value of PH3 when the phase difference between S3 and S4 is 90°. Similarly, the detection and calibration module can adjust the phase value of PH3 and detect the DC component of S2 to obtain the phase value of PH3 when the phase difference between S3 and S5 is 90°.

[0180] Specifically, the detection and calibration module adjusts the phase value of PH3 so that the phase difference between S3 and S4 is 0°. At this time, the first value of the DC component of S1 (i.e., the maximum value v1max) is detected. The phase value of PH3 is adjusted so that the phase difference between S3 and S4 is 180°. At this time, the second value of the DC component of S1 (i.e., the minimum value v1min) is detected. Similarly, the detection and calibration module adjusts the phase value of PH3 so that the phase difference between S3 and S5 is 0°. At this time, the first value of the DC component of S2 (i.e., the maximum value v2max) is detected. The phase value of PH3 is adjusted so that the phase difference between S3 and S5 is 180°. At this time, the second value of the DC component of S2 (i.e., the minimum value v2min) is detected. The detection and calibration module can determine the first target value of the DC component of S1 when the phase difference between S3 and S4 is 90° based on the first value and second value of the DC component of S1, that is, (v1max+v1min) / 2, that is, the first target value is the value of the DC component of S1 when the phase difference between S3 and S4 is 90°; and / or based on the first value and second value of the DC component of S2, can determine the second target value of the DC component of S2 when the phase difference between S3 and S5 is 90°, that is, (v2max+v2min) / 2, that is, the second target value is the value of the DC component of S2 when the phase difference between S3 and S5 is 90°.

[0181] In this implementation, the detection and calibration module adjusts the phase value of the third phase shifter so that the phase difference between the third signal and the fourth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the first signal. Based on the maximum and minimum values, a first target value of the DC component of the first signal is obtained when the phase difference between the third signal and the fourth signal is 90°. The detection and calibration module adjusts the phase value of the third phase shifter so that the phase difference between the third signal and the fifth signal is 0° and 180°, respectively, thereby obtaining the maximum and minimum values ​​of the DC component of the second signal. Based on the maximum and minimum values, a second target value of the DC component of the second signal is obtained when the phase difference between the third signal and the fifth signal is 90°.

[0182] Exemplarily, when the detection and calibration module obtains (v1max+v1min) / 2, it adjusts the phase value of PH3 so that the value of the DC component of S1 is (v1max+v1min) / 2, and records the phase value of PH3 at this time as the third phase value. In this case, it can be obtained that the phase difference between S3 and S4 is 90°. And / or when the detection and calibration module obtains (v2max+v2min) / 2, it adjusts the phase value of PH3 so that the value of the DC component of S2 is (v2max+v2min) / 2, and records the phase value of PH3 at this time as the fourth phase value. In this case, it can be obtained that the phase difference between S3 and S5 is 90°.

[0183] In this implementation, the detection and calibration module can adjust the phase value of the third phase shifter so that the value of the DC component of the first signal is a first target value, thereby obtaining a third phase value of the third phase shifter, and thus calibrating the phase of the I path of the IQ mixer based on the third phase value; the detection and calibration module can adjust the phase value of the third phase shifter so that the value of the DC component of the second signal is a second target value, thereby obtaining a fourth phase value of the third phase shifter, and thus calibrating the phase of the Q path of the IQ mixer based on the fourth phase value, thereby achieving a phase difference of 90° between the IQ two-path signals of the IQ mixer.

[0184] For example, Figure 14 As shown, the IQ mixer calibration circuit also includes a fourth phase shifter PH4 and / or a fifth phase shifter PH5. The second end of the I mixer is connected to the I terminal via PH4; the second end of the Q mixer is connected to the Q terminal via PH5; PH4 and PH5 are respectively connected to a detection and calibration module. The detection and calibration module is further configured to adjust the phase value of PH4 to a third phase value and the phase value of PH5 to a fourth phase value, for example, when the IQ mixer calibration circuit includes PH4 and PH5. Alternatively, the phase value of the fourth phase shifter or the phase value of the fifth phase shifter is adjusted based on the difference between the third phase value and the fourth phase value, for example, when the IQ mixer calibration circuit includes only PH4 or PH5.

[0185] In this implementation, the IQ mixer calibration circuit also includes a fourth phase shifter and / or a fifth phase shifter, and the fourth phase shifter and the fifth phase shifter are respectively connected to the detection calibration module. The detection calibration module can adjust the phase value of the fourth phase shifter and / or the fifth phase shifter based on the third phase value and the fourth phase value of the third phase shifter to achieve a phase difference of 90° between the IQ two signals of the IQ mixer.

[0186] For example, Figure 15As shown, the IQ mixer calibration circuit further includes a third attenuator ATT3 and / or a fourth attenuator ATT4. The second end of the I mixer is connected to the I terminal via PH4 and ATT3, respectively; the second end of the Q mixer is connected to the Q terminal via PH5 and ATT4, respectively. ATT3 and ATT4 are respectively connected to a detection and calibration module. The detection and calibration module can adjust the attenuation value of ATT3 or ATT4 based on the first and second values ​​of the DC component of S1 and the first and second values ​​of the DC component of S2.

[0187] In this implementation, the detection and calibration module can adjust the attenuation value of the third attenuator or the attenuation value of the fourth attenuator based on the maximum and minimum values ​​of the DC component of the first signal and the maximum and minimum values ​​of the DC component of the second signal. By adjusting the attenuation value of the third attenuator or the attenuation value of the fourth attenuator, the amplitude balance of the IQ two signals of the IQ mixer can be achieved.

[0188] Specifically, the detection and calibration module determines the amplitude ratio of the IQ mixer IQ signals based on the first and second values ​​of the DC component of S1 and the first and second values ​​of the DC component of S2. The amplitude ratio satisfies the following relationship:

[0189] X=│(v1max-v1min) / (v2max-v2min)│

[0190] The detection and calibration module determines the adjustment amount for ATT3 or ATT4 based on the amplitude ratio. If X is greater than 1, the adjustment amount for ATT3 is determined to be 20*log(X); if X is less than 1, the adjustment amount for ATT4 is determined to be 20*log(X). The attenuation value of ATT3 is adjusted based on the adjustment amount of ATT3, or the attenuation value of ATT4 is adjusted based on the adjustment amount of ATT4. When the IQ mixer includes ATT3 and ATT4, when determining the adjustment amount for ATT3, the attenuation value of ATT3 is increased by 20*log(X) to attenuate the amplitude of S1 by 20*log(X); when determining the adjustment amount for ATT4, the attenuation value of ATT4 is increased by 20*log(X) to attenuate the amplitude of S2 by 20*log(X). When the IQ mixer includes only ATT3, when determining the adjustment amount of ATT3, the attenuation value of ATT3 is increased by 20*log(X) to attenuate the amplitude of S1 by 20*log(X); when determining the adjustment amount of ATT4, the attenuation value of ATT3 is decreased by 20*log(X) to increase the amplitude of S1 by 20*log(X). When the IQ mixer includes only ATT4, when determining the adjustment amount of ATT3, the attenuation value of ATT4 is decreased by 20*log(X) to increase the amplitude of S2 by 20*log(X); when determining the adjustment amount of ATT4, the attenuation value of ATT4 is increased by 20*log(X) to decrease the amplitude of S2 by 20*log(X).

[0191] In this implementation, the detection and calibration module can determine the amplitude ratio of the IQ two-way signal of the IQ mixer based on the maximum value and minimum value of the DC component of the first signal and the maximum value and minimum value of the DC component of the second signal, thereby determining the amplitude imbalance of the IQ two-way signal according to the amplitude ratio, and determining the adjustment amount of the third attenuator or the adjustment amount of the fourth attenuator in the case of amplitude imbalance, and then adjusting the attenuation value of the corresponding attenuator based on the attenuation amount to achieve amplitude balance of the IQ two-way signal of the IQ mixer.

[0192] It can be seen that in the embodiment of the present application, a third phase shifter is added to the RF end of the IQ mixer, and the local oscillator is connected to the RF end through a switch device and the third phase shifter. Then, the signal input to the IQ mixer from the RF end can be provided by the local oscillator. The third phase shifter is connected to the detection and calibration module, and the detection and calibration module is connected to the second end of the I mixer and the second end of the Q mixer. The detection and calibration module can adjust the phase of the RF end signals input to the I mixer and the Q mixer by adjusting the phase value of the third phase shifter, and can determine the third phase value of the third phase shifter based on the first signal output from the second end of the I mixer, and / or can determine the fourth phase value of the third phase shifter based on the second signal output from the second end of the Q mixer. The third phase value and / or the fourth phase value are used to achieve a phase difference of 90° between the IQ two-way signals of the IQ mixer. In this way, without adding a baseband module, the IQ mixer can realize the phase imbalance calibration of the IQ two-way signal. There is no need for high-speed analog-to-digital conversion / digital-to-analog conversion modules and complex algorithms. The baseband chip resource usage is low, which reduces the implementation complexity.

[0193] See Figure 16 , Figure 16 This is a structural diagram of another IQ mixer calibration circuit provided in an embodiment of the present application, such as Figure 16 As shown, it includes an IQ mixer, a third phase shifter PH3, and a detection and calibration module. The first end of the IQ mixer's Lo is connected to the first end of the I-channel mixer of the IQ mixer; the first end of the Lo is connected to the first end of the Q-channel mixer of the IQ mixer. The RF end of the IQ mixer is connected to the third end of the I-channel mixer and the third end of the Q-channel mixer respectively through PH3. The second end of the I-channel mixer connected to the I end of the IQ mixer, the second end of the Q-channel mixer connected to the Q end of the IQ mixer, and PH3 are connected to the detection and calibration module. The detection and calibration module is configured to detect the DC component of the first signal S1 output from the second end of the I-channel mixer and the second signal S2 output from the second end of the Q-channel mixer, and determine the third phase value and the fourth phase value of PH3 based on S1 and S2, respectively.

[0194] Exemplarily, the RF output signal of the IQ mixer passes through PH3 and is then input into the I and Q mixers to generate a third signal S3. Lo outputs a local oscillator signal S, which is split into two signals: one local oscillator signal is input into the I mixer to generate a fourth signal S4, while the other local oscillator signal is input into the Q mixer to generate a fifth signal S5. The I mixer mixes S3 and S4 and outputs S1 from its second terminal. The Q mixer mixes S3 and S5 and outputs S2 from its second terminal. S3 has the same frequency as S4 and S5.

[0195] The detection and calibration module adjusts the phase value of PH3 so that the phase difference between S3 and S4 is 0°. At this time, the first value of the DC component of S1 (i.e., the maximum value v1max) is detected. The phase value of PH3 is adjusted so that the phase difference between S3 and S4 is 180°. At this time, the second value of the DC component of S1 (i.e., the minimum value v1min) is detected. Similarly, the detection and calibration module adjusts the phase value of PH3 so that the phase difference between S3 and S5 is 0°. At this time, the first value of the DC component of S2 (i.e., the maximum value v2max) is detected. The phase value of PH3 is adjusted so that the phase difference between S3 and S5 is 180°. At this time, the second value of the DC component of S2 (i.e., the minimum value v2min) is detected. The detection and calibration module can determine the first target value of the DC component of S1 when the phase difference between S3 and S4 is 90° based on the first value and second value of the DC component of S1, that is, (v1max+v1min) / 2, that is, the first target value is the value of the DC component of S1 when the phase difference between S3 and S4 is 90°; and / or based on the first value and second value of the DC component of S2, can determine the second target value of the DC component of S2 when the phase difference between S3 and S5 is 90°, that is, (v2max+v2min) / 2, that is, the second target value is the value of the DC component of S2 when the phase difference between S3 and S5 is 90°.

[0196] The detection and calibration module adjusts the phase value of PH3 so that the DC component of S1 is (v1max+v1min) / 2, and records the phase value of PH3 at this time as the third phase value. In this case, the phase difference between S3 and S4 is 90°. And / or when the detection and calibration module obtains (v2max+v2min) / 2, it adjusts the phase value of PH3 so that the DC component of S2 is (v2max+v2min) / 2, and records the phase value of PH3 at this time as the fourth phase value. In this case, the phase difference between S3 and S5 is 90°.

[0197] For example, Figure 17 As shown, the IQ mixer calibration circuit also includes a fourth phase shifter PH4 and / or a fifth phase shifter PH5. The second end of the I mixer is connected to the I terminal via PH4; the second end of the Q mixer is connected to the Q terminal via PH5; PH4 and PH5 are respectively connected to a detection and calibration module. The detection and calibration module is further configured to adjust the phase value of PH4 to a third phase value and the phase value of PH5 to a fourth phase value, for example, when the IQ mixer calibration circuit includes PH4 and PH5. Alternatively, the phase value of the fourth phase shifter or the phase value of the fifth phase shifter is adjusted based on the difference between the third phase value and the fourth phase value, for example, when the IQ mixer calibration circuit includes only PH4 or PH5.

[0198] For example, Figure 18 As shown, the IQ mixer calibration circuit also includes a third attenuator ATT3 and / or a fourth attenuator ATT4. The second end of the I-channel mixer is connected to the I end through PH4 and ATT3 in sequence; the second end of the Q-channel mixer is connected to the Q end through PH5 and ATT4 in sequence; ATT3 and ATT4 are respectively connected to the detection and calibration module. The detection and calibration module can adjust the attenuation value of ATT3 or ATT4 based on the first value and the second value of the DC component of S1 and the first value and the second value of the DC component of S2. For specific implementation methods, please refer to Figure 15 The relevant descriptions in the illustrated embodiments can achieve the same or similar beneficial effects.

[0199] For example, Figure 19 As shown, the second end of the IQ mixer's Lo is also connected to the IQ mixer's RF terminal via a switch. When the switch SW is closed, S3 is the local oscillator signal input from the Lo to the IQ mixer's RF terminal and then output via PH3. In calibration mode, with SW closed, the local oscillator signal output from the Lo passes through SW to the RF terminal, then from the RF terminal to PH3, and finally outputs S3 via PH3. In other words, the S3 input to the mixer from the RF terminal can originate from the Lo.

[0200] See Figure 20 , Figure 20 A flow chart of a calibration method provided in an embodiment of the present application, which can be applied to Figures 8 to 11 The IQ mixer calibration circuit in any embodiment. Figure 20 As shown, it includes steps 2001-2005:

[0201] 2001: The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer;

[0202] 2002: The local oscillator inputs a fourth signal to the I-channel mixer through the first phase shifter, and inputs a fifth signal to the Q-channel mixer through the second phase shifter; the third signal has the same frequency as the fourth signal and the fifth signal;

[0203] 2003: the I-channel mixer mixes the third signal and the fourth signal and outputs the first signal from the second end;

[0204] 2004: the Q-channel mixer mixes the third signal and the fifth signal and outputs the second signal from the second end;

[0205] 2005: The detection and calibration module determines a first phase value of the first phase shifter based on the first signal, and / or determines a second phase value of the second phase shifter based on the second signal.

[0206] In one possible implementation, determining a first phase value of a first phase shifter based on the first signal includes:

[0207] The detection and calibration module adjusts the phase value of the first phase shifter to a first phase value; when the value of the first phase shifter is the first phase value, the value of the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0208] Determining a second phase value of a second phase shifter based on the second signal includes:

[0209] The detection and calibration module adjusts the value of the second phase shifter to a second phase value; when the value of the second phase shifter is the second phase value, the value of the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0210] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0211] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0212] In a possible implementation, the method further includes:

[0213] The detection calibration module adjusts the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

[0214] In one possible implementation, adjusting the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes:

[0215] The detection and calibration module determines an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal;

[0216] The detection and calibration module determines an adjustment amount of the first attenuator or an adjustment amount of the second attenuator based on the amplitude ratio;

[0217] The detection and calibration module adjusts the attenuation value of the first attenuator based on the adjustment amount of the first attenuator; or adjusts the attenuation value of the second attenuator based on the adjustment amount of the second attenuator.

[0218] In a possible implementation, the third signal is a local oscillator signal input from a local oscillator to a radio frequency terminal of the IQ mixer when the switch device is closed.

[0219] The specific implementation of each step can refer to Figures 8 to 11 The description in the illustrated embodiment can achieve the same or similar beneficial effects.

[0220] See Figure 21 , Figure 21 A flow chart of another calibration method provided in an embodiment of the present application, which can be applied to Figures 12 to 15 The IQ mixer calibration circuit in any embodiment. Figure 21 As shown, it includes steps 2101-2105:

[0221] 2101: The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer. The third signal is obtained by a local oscillator signal input to the radio frequency end of the IQ mixer by a local oscillator when the switch device is closed and then passing through a third phase shifter.

[0222] 2102: The local oscillator inputs the fourth signal to the I mixer and the fifth signal to the Q mixer; the third signal has the same frequency as the fourth signal and the fifth signal;

[0223] 2103: The I-channel mixer mixes the third signal and the fourth signal and outputs the first signal from the second end;

[0224] 2104: The Q-channel mixer mixes the third signal and the fifth signal and outputs the second signal from the second end;

[0225] 2105: The detection and calibration module determines a third phase value of the third phase shifter based on the first signal, and / or determines a fourth phase value of the third phase shifter based on the second signal.

[0226] In one possible implementation, determining a third phase value of a third phase shifter based on the first signal includes:

[0227] The detection and calibration module adjusts the value of the third phase shifter to a third phase value; when the value of the third phase shifter is the third phase value, the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°;

[0228] Determining a fourth phase value of a third phase shifter based on the second signal includes:

[0229] The detection and calibration module adjusts the value of the third phase shifter to a fourth phase value; when the value of the third phase shifter is the fourth phase value, the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

[0230] In one possible implementation, the first target value is obtained based on a first value and a second value of a DC component of the first signal; when a phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; and when a phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value;

[0231] The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

[0232] In a possible implementation, the method further includes:

[0233] The detection and calibration module adjusts the phase value of the fourth phase shifter to the third phase value, and / or adjusts the phase value of the fifth phase shifter to the fourth phase value.

[0234] In a possible implementation, the method further includes:

[0235] The detection calibration module adjusts the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on the difference between the third phase value and the fourth phase value.

[0236] In a possible implementation, the method further includes:

[0237] The detection calibration module adjusts the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

[0238] In one possible implementation, adjusting the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes:

[0239] Determine an amplitude ratio of two IQ signals of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal and a first value and a second value of a DC component of the second signal;

[0240] determining an adjustment amount of the third attenuator or an adjustment amount of the fourth attenuator based on the amplitude ratio;

[0241] The attenuation value of the third attenuator is adjusted based on the adjustment amount of the third attenuator; or the attenuation value of the fourth attenuator is adjusted based on the adjustment amount of the fourth attenuator.

[0242] The specific implementation of each step can refer to Figures 12 to 15 The description in the illustrated embodiment can achieve the same or similar beneficial effects.

[0243] See Figure 22 , Figure 22 A schematic diagram of the structure of a communication device provided in an embodiment of the present application is shown in FIG. Figure 22 As shown, the communication device includes an IQ mixer calibration circuit 2201, which can be Figures 8 to 11 、 Figures 12 to 15 or Figures 16 to 19 The IQ mixer calibration circuit in any one of the embodiments of the present invention can be a transmitter or a receiver of a communication device, or a radio frequency front end in a transmitter or a receiver.

[0244] See Figure 23 , Figure 23 A schematic diagram of the structure of a communication device provided in an embodiment of the present application is shown in FIG. Figure 23 As shown, the communication device includes a processor 2301, a memory 2302, a communication device 2303, and one or more programs, wherein the one or more programs are stored in the memory and configured to cooperate with the communication device to achieve communication when executed by the processor. Figure 22The communication device shown in . The communication device can be a terminal device, an access network device, etc. The terminal device includes but is not limited to a user device, a user unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal device, a mobile terminal device, a user terminal device, a wireless electronic device, a user agent, a user device, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device, a processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in the Internet of Things, a home appliance, a virtual reality device, a terminal device in a future 5G network, or a terminal device in a future evolved public land mobile network (PLMN), etc. The access network device can include various forms of base stations, such as: a macro base station, a micro base station (also known as a small station), a relay station, an access point, etc. In systems using different wireless access technologies, the names of devices with base station functions may be different. For example, in 5GS, it is called gNB; in Long-Term Evolution (LTE) systems, it is called evolved NodeB (eNB or eNodeB); in third generation (3G) systems, it is called Node B, etc.

[0245] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0246] It should be understood that the processor mentioned in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0247] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct RAM bus random access memory (DR RAM).

[0248] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) is integrated into the processor.

[0249] It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0250] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0251] In the several embodiments provided in this application, it should be understood that the disclosed circuits, devices, and methods can be implemented in other ways.

[0252] In this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, and B exists alone, where A and B can be singular or plural. In the text description of this application, the character " / " generally indicates that the associated objects are in an "or" relationship.

[0253] The steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs.

[0254] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An IQ mixer calibration circuit, characterized in that: It includes an IQ mixer, a first phase shifter, a second phase shifter and a detection and calibration module; A first end of the local oscillator of the IQ mixer is connected to a first end of the I-channel mixer of the IQ mixer through the first phase shifter; The first end of the local oscillator is connected to the first end of the Q-channel mixer of the IQ mixer through the second phase shifter; The second end of the I-channel mixer connected to the I end of the IQ mixer, the second end of the Q-channel mixer connected to the Q end of the IQ mixer, the first phase shifter, and the second phase shifter are respectively connected to the detection and calibration module; The detection and calibration module is used to determine the first phase value of the first phase shifter and the second phase value of the second phase shifter based on the first signal output from the second end of the I mixer and the second signal output from the second end of the Q mixer.

2. The IQ mixer calibration circuit according to claim 1, wherein: The first signal is obtained by mixing the third signal and the fourth signal by the I-channel mixer; the third signal is input by the radio frequency end of the IQ mixer, and the fourth signal is input by the local oscillator signal output by the local oscillator after passing through the first phase shifter; The second signal is obtained by mixing the third signal and the fifth signal by the Q-channel mixer; the fifth signal is input by the local oscillator signal output by the local oscillator after passing through the second phase shifter; the third signal has the same frequency as the fourth signal and the fifth signal.

3. The IQ mixer calibration circuit according to claim 2, wherein: The detection and calibration module is specifically used for: adjusting the phase value of the first phase shifter to the first phase value; when the value of the first phase shifter is the first phase value, the value of the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°; and / or adjusting the value of the second phase shifter to the second phase value; when the value of the second phase shifter is the second phase value, the value of the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

4. The IQ mixer calibration circuit according to claim 3, wherein: The first target value is obtained based on a first value and a second value of a DC component of the first signal; when the phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; when the phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value; The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

5. The IQ mixer calibration circuit according to any one of claims 1 to 4, characterized in that: Also comprising a first attenuator and / or a second attenuator; The second end of the I-channel mixer is connected to the I end through the first attenuator; the second end of the Q-channel mixer is connected to the Q end through the second attenuator; the first attenuator and the second attenuator are respectively connected to the detection and calibration module.

6. The IQ mixer calibration circuit according to claim 5, wherein: The detection and calibration module is further used for: The attenuation value of the first attenuator or the second attenuator is adjusted based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

7. The IQ mixer calibration circuit according to claim 6, wherein: The detection and calibration module is specifically used for: Determining an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal, and a first value and a second value of a DC component of the second signal; determining an adjustment amount of the first attenuator or an adjustment amount of the second attenuator based on the amplitude ratio; The attenuation value of the first attenuator is adjusted based on the adjustment amount of the first attenuator; or the attenuation value of the second attenuator is adjusted based on the adjustment amount of the second attenuator.

8. The IQ mixer calibration circuit according to any one of claims 2 to 6, wherein: The second end of the local oscillator is connected to the radio frequency end of the IQ mixer through a switch device.

9. The IQ mixer calibration circuit according to claim 8, wherein: The third signal is a local oscillator signal input from the local oscillator to the radio frequency end of the IQ mixer when the switch device is closed.

10. An IQ mixer calibration circuit, characterized in that: It includes an IQ mixer, a third phase shifter and a detection and calibration module; A first end of the local oscillator of the IQ mixer is connected to the first ends of the I mixer and the Q mixer of the IQ mixer respectively; The second end of the local oscillator is connected to the radio frequency end of the IQ mixer through a switch device and the third phase shifter in sequence; The second end of the I-channel mixer connected to the I end of the IQ mixer, the second end of the Q-channel mixer connected to the Q end of the IQ mixer, and the third phase shifter are respectively connected to the detection and calibration module; The detection and calibration module is configured to respectively determine a third phase value and a fourth phase value of the third phase shifter based on a first signal output from a second end of the I mixer and a second signal output from a second end of the Q mixer.

11. The IQ mixer calibration circuit according to claim 10, wherein: The first signal is obtained by mixing the third signal and the fourth signal by the I-channel mixer; the third signal is obtained by inputting a local oscillator signal from the local oscillator to the radio frequency end of the IQ mixer and then passing through the third phase shifter when the switch device is closed; the fourth signal is input from the local oscillator to the I-channel mixer; The second signal is obtained by mixing the third signal and the fifth signal by the Q-channel mixer; the fifth signal is input to the Q-channel mixer by the local oscillator; and the third signal has the same frequency as the fourth signal and the fifth signal.

12. The IQ mixer calibration circuit according to claim 11, wherein: The detection and calibration module is specifically used for: adjusting the value of the third phase shifter to the third phase value; when the value of the third phase shifter is the third phase value, the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°; and / or adjusting the value of the third phase shifter to the fourth phase value; when the value of the third phase shifter is the fourth phase value, the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

13. The IQ mixer calibration circuit according to claim 12, wherein: The first target value is obtained based on a first value and a second value of a DC component of the first signal; when the phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; when the phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value; The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

14. The IQ mixer calibration circuit according to claim 13, wherein: Also comprising a fourth phase shifter and / or a fifth phase shifter; The second end of the I-channel mixer is connected to the I end through the fourth phase shifter; the second end of the Q-channel mixer is connected to the Q end through the fifth phase shifter; the fourth phase shifter and the fifth phase shifter are respectively connected to the detection and calibration module.

15. The IQ mixer calibration circuit according to claim 14, wherein: The detection and calibration module is further configured to adjust the phase value of the fourth phase shifter to the third phase value; and adjust the phase value of the fifth phase shifter to the fourth phase value.

16. The IQ mixer calibration circuit according to claim 14, wherein: The detection and calibration module is further configured to adjust the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on a difference between the third phase value and the fourth phase value.

17. The IQ mixer calibration circuit according to any one of claims 14 to 16, characterized in that: further comprising a third attenuator and / or a fourth attenuator; The second end of the I-channel mixer is connected to the I end through the fourth phase shifter and the third attenuator in sequence; the second end of the Q-channel mixer is connected to the Q end through the fifth phase shifter and the fourth attenuator in sequence; the third attenuator and the fourth attenuator are respectively connected to the detection and calibration module.

18. The IQ mixer calibration circuit according to claim 17, wherein: The detection calibration module is further configured to adjust the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

19. The IQ mixer calibration circuit according to claim 18, wherein: The detection and calibration module is specifically used for: Determining an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal, and a first value and a second value of a DC component of the second signal; determining an adjustment amount of the third attenuator or an adjustment amount of the fourth attenuator based on the amplitude ratio; The attenuation value of the third attenuator is adjusted based on the adjustment amount of the third attenuator; or the attenuation value of the fourth attenuator is adjusted based on the adjustment amount of the fourth attenuator.

20. A calibration method, characterized in that: An IQ mixer calibration circuit applied to any one of claims 1-9; the method comprising: The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer; The local oscillator inputs a fourth signal to the I-channel mixer through the first phase shifter, and inputs a fifth signal to the Q-channel mixer through the second phase shifter; the third signal has the same frequency as the fourth signal and the fifth signal; The I-channel mixer mixes the third signal and the fourth signal and then outputs the first signal from the second end; The Q-channel mixer mixes the third signal and the fifth signal and then outputs a second signal from the second end; The detection calibration module determines a first phase value of the first phase shifter based on the first signal, and / or determines a second phase value of the second phase shifter based on the second signal.

21. The method according to claim 20, characterized in that The determining a first phase value of the first phase shifter based on the first signal includes: The detection and calibration module adjusts the phase value of the first phase shifter to the first phase value; when the value of the first phase shifter is the first phase value, the value of the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°; The determining a second phase value of the second phase shifter based on the second signal includes: The detection calibration module adjusts the value of the second phase shifter to the second phase value; when the value of the second phase shifter is the second phase value, the value of the DC component of the second signal is the second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

22. The method according to claim 21, characterized in that The first target value is obtained based on a first value and a second value of a DC component of the first signal; when the phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; when the phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value; The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

23. The method according to claim 22, characterized in that The method further comprises: The detection calibration module adjusts the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

24. The method according to claim 23, wherein The adjusting the attenuation value of the first attenuator or the second attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes: The detection and calibration module determines an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal, and a first value and a second value of a DC component of the second signal; The detection calibration module determines an adjustment amount of the first attenuator or an adjustment amount of the second attenuator based on the amplitude ratio; The detection calibration module adjusts the attenuation value of the first attenuator based on the adjustment amount of the first attenuator; or adjusts the attenuation value of the second attenuator based on the adjustment amount of the second attenuator.

25. The method according to any one of claims 20 to 24, characterized in that The third signal is a local oscillator signal input from the local oscillator to the radio frequency end of the IQ mixer when the switch device is closed.

26. A calibration method, characterized in that: An IQ mixer calibration circuit applied to any one of claims 10-19; the method comprising: The radio frequency end of the IQ mixer inputs a third signal to the I mixer and the Q mixer; the third signal is obtained by the local oscillator signal input to the radio frequency end of the IQ mixer by the local oscillator when the switch device is closed and then passing through the third phase shifter; The local oscillator inputs a fourth signal to the I-channel mixer and a fifth signal to the Q-channel mixer; the third signal has the same frequency as the fourth signal and the fifth signal; The I-channel mixer mixes the third signal and the fourth signal and then outputs the first signal from the second end; The Q-channel mixer mixes the third signal and the fifth signal and then outputs a second signal from the second end; The detection and calibration module determines a third phase value of the third phase shifter based on the first signal, and / or determines a fourth phase value of the third phase shifter based on the second signal.

27. The method according to claim 26, characterized in that The determining a third phase value of the third phase shifter based on the first signal includes: The detection calibration module adjusts the value of the third phase shifter to the third phase value; when the value of the third phase shifter is the third phase value, the DC component of the first signal is a first target value; the first target value is the value of the DC component of the first signal when the phase difference between the third signal and the fourth signal is 90°; Determining a fourth phase value of the third phase shifter based on the second signal includes: The detection calibration module adjusts the value of the third phase shifter to the fourth phase value; when the value of the third phase shifter is the fourth phase value, the DC component of the second signal is a second target value; the second target value is the value of the DC component of the second signal when the phase difference between the third signal and the fifth signal is 90°.

28. The method according to claim 27, characterized in that The first target value is obtained based on a first value and a second value of a DC component of the first signal; when the phase difference between the third signal and the fourth signal is 0°, the DC component of the first signal has the first value; when the phase difference between the third signal and the fourth signal is 180°, the DC component of the first signal has the second value; The second target value is obtained based on the first value and the second value of the DC component of the second signal; when the phase difference between the third signal and the fifth signal is 0°, the DC component of the second signal is the first value; when the phase difference between the third signal and the fifth signal is 180°, the DC component of the second signal is the second value.

29. The method according to claim 28, characterized in that The method further comprises: The detection calibration module adjusts the phase value of the fourth phase shifter to the third phase value, and / or adjusts the phase value of the fifth phase shifter to the fourth phase value.

30. The method according to claim 28, wherein The method further comprises: The detection calibration module adjusts the phase value of the fourth phase shifter or the phase value of the fifth phase shifter based on the difference between the third phase value and the fourth phase value.

31. The method according to any one of claims 28 to 30, characterized in that The method further comprises: The detection calibration module adjusts the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal.

32. The method according to claim 31, characterized in that The adjusting the attenuation value of the third attenuator or the fourth attenuator based on the first value and the second value of the DC component of the first signal and the first value and the second value of the DC component of the second signal includes: Determining an amplitude ratio of the IQ two-way signal of the IQ mixer; the amplitude ratio is determined based on a first value and a second value of a DC component of the first signal, and a first value and a second value of a DC component of the second signal; determining an adjustment amount of the third attenuator or an adjustment amount of the fourth attenuator based on the amplitude ratio; The attenuation value of the third attenuator is adjusted based on the adjustment amount of the third attenuator; or the attenuation value of the fourth attenuator is adjusted based on the adjustment amount of the fourth attenuator.

33. A communication device, characterized in that: The method comprises the IQ mixer calibration circuit according to any one of claims 1 to 9; or comprises the IQ mixer calibration circuit according to any one of claims 10 to 19.

34. A communication device, characterized in that: It comprises a processor, a memory, a communication device as described in claim 33, and one or more programs, wherein the one or more programs are stored in the memory and are configured to cooperate with the communication device to achieve communication when executed by the processor.

Images