A radio frequency transceiver gain flatness adaptive calibration circuit and method

Abstract

The application discloses a kind of radio frequency transceiver gain flatness adaptive calibration circuit and method, it is related to radio frequency circuit technical field.The present application, by introducing gain flatness adaptive calibration circuit in radio frequency receiving or transmitting channel, after the completion of circuit manufacture, radio frequency channel gain flatness can be automatically detected and calibrated, improve the adverse effects of process deviation, power voltage variation, temperature fluctuation (PVT) on radio frequency transceiver channel gain flatness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radio frequency circuit, in particular to a kind of radio frequency transceiver gain flatness adaptive calibration circuit and method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and can not constitute prior art.

[0003] Radio frequency transceiver is widely used in modern communication system, phased array system.In order to realize long distance communication, the receiver usually requires linear amplification of weak signal received by antenna under certain power consumption, to meet the requirements of signal processing of the latter circuit;Transmitter usually requires that the signal can be power amplified while maintaining high efficiency and no distortion;In phased array system, radio frequency transceiver controls the signal amplitude and phase of each unit of antenna by electronic method, which can realize the control of beam shape and direction, multi-target tracking, etc.

[0004] Gain flatness represents the fluctuation of radio frequency circuit gain in a certain frequency band, and describes the signal amplitude distortion characteristics in the frequency band, which is particularly important in wideband radio frequency system.In the design of radio frequency circuit, due to the limitation of manufacturing process (P) accuracy, there will always be a deviation between the actual value and the design value of each component;When the circuit scale is large, the cumulative effect of active device and passive device deviation will cause a large deviation between the actual value and the design value of circuit gain flatness.Meanwhile, when the circuit works, temperature (T) fluctuation and power supply voltage (V) change will have a certain impact on device parameters, which will worsen the gain flatness.When the circuit is designed using discrete components, the components that meet the gain flatness of the circuit can be found by screening;In integrated circuit design, the circuit parameters are usually adjusted by multiple times of flow sheet to meet the design requirements of gain flatness and other parameters.However, the screening of discrete components or multiple times of chip flow sheet will increase the product development cost and prolong the product development cycle. SUMMARY

[0005] The present application aims at the problems in the prior art, and provides a radio frequency transceiver gain flatness adaptive calibration circuit and method, which can automatically detect and calibrate the gain flatness of radio frequency channel after the completion of circuit manufacturing by introducing gain flatness adaptive calibration circuit in radio frequency receiving or transmitting channel, to improve the adverse effects of process deviation, power supply voltage change and temperature fluctuation (PVT) on radio frequency transceiver channel gain flatness.

[0006] The technical scheme of the present application is as follows:

[0007] A radio frequency transceiver gain flatness adaptive calibration circuit, comprising:

[0008] The radio frequency signal generating circuit, the digital control circuit, the digital-analog conversion circuit, the power detection circuit, the gain slope adjustment circuit, the first radio frequency circuit, and the second radio frequency circuit.

[0009] The gain slope adjustment circuit is connected in series between the first radio frequency circuit and the second radio frequency circuit in the radio frequency channel; the power detection circuit, the digital-analog conversion circuit, the digital control circuit, and the radio frequency signal generating circuit are connected in series; the power detection circuit is connected with the radio frequency output of the radio frequency channel; the digital control circuit is connected with the gain slope adjustment circuit; and the radio frequency signal generating circuit is connected with the radio frequency input of the radio frequency channel.

[0010] Further, the first radio frequency circuit and the second radio frequency circuit have a radio frequency signal processing function.

[0011] Further, the radio frequency signal processing function comprises:

[0012] One or more of the following functions: attenuation, amplification, phase shift, filtering, power combination / power division, and frequency mixing.

[0013] Further, the gain slope adjustment circuit can adjust the gain flatness of the radio frequency channel under the action of the digital control circuit.

[0014] Further, the power detection circuit detects the power amplitude of the radio frequency signal output by the radio frequency channel, and the digital-analog conversion circuit converts the analog signal output by the power detection circuit into a digital signal.

[0015] Further, the digital control circuit obtains the gain flatness of the radio frequency channel according to the digital signal, compares the gain flatness with a desired flatness threshold, and controls the gain slope adjustment circuit to adjust the gain flatness of the radio frequency channel according to the comparison result.

[0016] Further, the digital control circuit also controls the radio frequency signal generating circuit to generate radio frequency signals of different frequencies and constant amplitudes as test signals input to the radio frequency channel.

[0017] The present application also provides a radio frequency transceiver gain flatness adaptive calibration method based on the radio frequency transceiver gain flatness adaptive calibration circuit.

[0018] The gain slope adjustment circuit adjusts the gain flatness of the radio frequency channel under the action of the digital control circuit; the power detection circuit detects the power amplitude of the radio frequency signal output by the radio frequency channel, the digital-analog conversion circuit converts the analog signal output by the power detection circuit into a digital signal, the digital control circuit obtains the gain flatness of the radio frequency channel according to the digital signal, and compares the gain flatness with the expected flatness threshold, controls the gain slope adjustment circuit to adjust the gain flatness of the radio frequency channel according to the comparison result, and controls the radio frequency signal generation circuit to generate radio frequency signals of different frequencies and constant amplitudes as test signals input into the radio frequency channel.

[0019] Further, a radio frequency transceiver gain flatness adaptive calibration method comprises the following specific steps:

[0020] Step S1: After the calibration starts, the digital control circuit is initialized;

[0021] Step S2: Under the action of the output signal of the digital control circuit, the gain slope adjustment circuit initializes the gain slope of the radio frequency channel, and the radio frequency signal generation circuit outputs radio frequency signals with a frequency of f1 and a power of P0; a variable j is used to store the number of gain slope adjustments, and a variable i is used to store the number of times of inputting the test signal and sampling the output power under the current gain slope after each gain slope adjustment;

[0022] Step S3: The variable j is assigned a value of 1, the variable i is assigned a value of 1, and it is judged whether j is greater than m; at most m times of slope adjustment can be performed, and the input of the gain flatness test signal of the radio frequency channel, the detection of the output power, the digital-analog conversion, and the saving of the output radio frequency signal power amplitude information are performed each time the slope adjustment is performed;

[0023] Step S4: According to the judgment result, adaptive calibration is performed.

[0024] Further, the step S4 comprises:

[0025] When j is greater than m, it indicates that the gain flatness has not reached the expectation after m times of gain slope adjustment, and at this time, the flatness adjustment is ended, and the best flatness in the m times of slope adjustment is taken as the final flatness adjustment result;

[0026] If j is less than or equal to m, j is increased by 1, and then it is judged whether i is greater than n, n is the frequency range f1~f nThe number of inner test signal frequency points; if i is greater than n, it indicates that the radio frequency channel has completed n times of different frequency same power P0 test signal input, output power detection, digital to analog conversion, and saving of output radio frequency signal power amplitude information under the current gain slope, and the gain flatness and gain slope can be calculated, if the gain flatness is less than the set flatness threshold, the algorithm ends, and the current gain slope is the final gain slope for adjustment; if the expected gain flatness is not reached, the digital control circuit outputs a signal to act on the gain slope adjustment circuit to adjust the gain slope of the radio frequency channel, and the radio frequency signal generation circuit generates n test signals of different frequencies and same power to input the radio frequency channel in turn, performs output power detection, digital to analog conversion, and saves the output radio frequency signal power amplitude information, recalculates the gain flatness and gain slope of the radio frequency channel, and judges again whether the gain slope of the radio frequency channel meets the requirements.

[0027] Compared with the prior art, the beneficial effects of the present application are:

[0028] (1) Under loop control, the gain flatness of the radio frequency transceiver can be self-adaptively calibrated; after the circuit is manufactured, the gain flatness of the radio frequency transceiver channel can be optimized, the product development cost is reduced, and the product development cycle is shortened;

[0029] (2) The influence of process, power supply, and temperature fluctuation on the performance of the radio frequency channel can be reduced;

[0030] (3) The circuit is simple, easy to implement, and has good engineering practicability. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of a gain curve of a radio frequency transceiver gain flatness self-adaptive calibration circuit according to the present application;

[0032] Figure 2 is a schematic diagram of a gain curve of a radio frequency transceiver gain flatness self-adaptive calibration circuit according to the present application;

[0033] Figure 3 is a schematic diagram of a radio frequency transceiver gain flatness self-adaptive calibration process according to the present application Figure 1 ;

[0034] Figure 4 is a schematic diagram of a radio frequency transceiver gain flatness self-adaptive calibration process according to the present application Figure 2 ;

[0035] Figure 5 is a schematic diagram of a radio frequency transceiver gain flatness self-adaptive calibration algorithm flow according to the present application. DETAILED DESCRIPTION

[0036] It is to be noted that the relational terms herein, such as first and second, and the like, are used solely to distinguish one from another entity or action without necessarily requiring or implying any actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0037] The features and advantages of the present application will be further described in the following detailed description of the embodiments.

[0038] Embodiment One

[0039] Please refer to Figure 1 A radio frequency transceiver gain flatness adaptive calibration circuit comprises:

[0040] A radio frequency signal generating circuit, a digital control circuit, a digital-to-analog conversion circuit, a power detection circuit, a gain slope adjustment circuit, a first radio frequency circuit, and a second radio frequency circuit.

[0041] The gain slope adjustment circuit is connected in series between the first radio frequency circuit and the second radio frequency circuit in a radio frequency channel; the power detection circuit, the digital-to-analog conversion circuit, the digital control circuit, and the radio frequency signal generating circuit are connected in series; the power detection circuit is connected with a radio frequency output of the radio frequency channel; the digital control circuit is connected with the gain slope adjustment circuit; and the radio frequency signal generating circuit is connected with a radio frequency input of the radio frequency channel.

[0042] In the embodiment, specifically, the first radio frequency circuit and the second radio frequency circuit have radio frequency signal processing functions, including one or more of the following functional units: attenuation, amplification, phase shift, filtering, power combination / power division, and frequency mixing.

[0043] In the embodiment, specifically, the gain slope adjustment circuit can adjust the gain flatness of the radio frequency channel under the action of the digital control circuit. The power detection circuit detects the power amplitude of the radio frequency signal output by the radio frequency channel, and the digital-to-analog conversion circuit converts the analog signal output by the power detection circuit into a digital signal. The digital control circuit obtains the gain flatness of the radio frequency channel according to the digital signal, compares it with the expected flatness threshold, and controls the gain slope adjustment circuit to adjust the gain flatness of the radio frequency channel according to the comparison result. The digital control circuit also controls the radio frequency signal generation circuit to generate radio frequency signals of different frequencies and constant amplitudes as test signals input into the radio frequency channel.

[0044] Referring to Figure 2 , a gain curve diagram of a radio frequency transceiver gain flatness adaptive calibration circuit. Curve a represents the gain curve of the gain slope adjustment circuit in the radio frequency channel; curve b represents the overall gain curve of the first radio frequency circuit and the second radio frequency circuit, which is the circuit other than the gain slope adjustment circuit in the radio frequency channel; curve c represents the gain curve of the entire radio frequency channel formed by superimposing curve a and curve b; the curve c in the shadow part is the optimal flatness in the frequency range f1~f n , which is the expected gain curve in the circuit design stage; optionally, Figure 2 (a) the center frequency of curve a is higher than curve b, Figure 2 (b) the center frequency of curve a is lower than curve b.

[0045] Referring to Figure 3 , the present application is a radio frequency transceiver gain flatness adaptive calibration process diagram Figure 1 , curve a j The center frequency of curve a is higher than curve b, j is a natural number, 1≤j≤m, m is defined as the maximum number of slope adjustments, and for convenience of description, Figure 3 The number of slope adjustments is described as the maximum number m.

[0046] Referring to Figure 3 (a). Optionally, assuming that after the radio frequency channel circuit is manufactured, due to PVT fluctuation, the gain curve of the gain slope adjustment circuit is a1, the overall gain curve of the first radio frequency circuit and the second radio frequency circuit is b, and the gain curve of the radio frequency channel after superimposing the curves a1 and b is c1, the gain is positive in the frequency range f1~f n , the high-frequency gain is high, and the low-frequency gain is low; by configuring the slope adjustment circuit through the digital control circuit, the gain curve of the slope adjustment circuit is adjusted to a2, and the overall gain curve of the radio frequency channel is c2, the positive gain slope is reduced, and the flatness is improved; continuously adjusting in the same direction, after m times of adjustment, the gain curve of the slope adjustment circuit is adjusted to a m , and the overall gain curve of the radio frequency channel is c m, the gain flatness reaches the expectation, that is, the gain fluctuation in the band is less than the expected flatness threshold.

[0047] Referring to Figure 3 (b). Alternatively, assuming that the radio frequency channel circuit is manufactured, due to PVT fluctuation, the gain curve of the gain slope adjustment circuit is a1, the overall gain curve of the first radio frequency circuit and the second radio frequency circuit is b, and the radio frequency channel gain curve after superposition of the curves a1 and b is c1, the frequency range f1~f n The gain is negative slope in the band, the high frequency gain is low, and the low frequency gain is high; the gain curve of the slope adjustment circuit is adjusted to a2 through the digital control circuit, the overall gain curve of the radio frequency channel is c2, the negative slope of the gain is reduced, and the flatness is better; the adjustment is continuously adjusted in the same direction, after m times of adjustment, the gain curve of the slope adjustment circuit is adjusted to a m , the overall gain curve of the radio frequency channel is c m , and the gain flatness reaches the expectation, that is, the gain fluctuation in the band is less than the expected flatness threshold.

[0048] Referring to Figure 4 The gain flatness self-adaptive calibration process of the radio frequency transceiver Figure 2 , the curve a j The center frequency is lower than the curve b, j is a natural number, 1≤j≤m, and m is defined as the maximum value of the slope adjustment times, for the convenience of description, Figure 4 The slope adjustment times are described according to the maximum value m.

[0049] Referring to Figure 4 (a). Alternatively, assuming that the radio frequency channel circuit is manufactured, due to PVT fluctuation, the gain curve of the gain slope adjustment circuit is a1, the overall gain curve of the first radio frequency circuit and the second radio frequency circuit is b, and the radio frequency channel gain curve after superposition of the curves a1 and b is c1, the frequency range f1~f n The gain is negative slope in the band, the high frequency gain is low, and the low frequency gain is high; the gain curve of the slope adjustment circuit is adjusted to a2 through the digital control circuit, the overall gain curve of the radio frequency channel is c2, the negative slope of the gain is reduced, and the flatness is better; the adjustment is continuously adjusted in the same direction, after m times of adjustment, the gain curve of the slope adjustment circuit is adjusted to a m , the overall gain curve of the radio frequency channel is c m , and the gain flatness reaches the expectation, that is, the gain fluctuation in the band is less than the expected flatness threshold.

[0050] Referring to Figure 4 (b). Alternatively, assuming that the radio frequency channel circuit is manufactured, due to PVT fluctuation, the gain curve of the gain slope adjustment circuit is a1, the overall gain curve of the first radio frequency circuit and the second radio frequency circuit is b, and the radio frequency channel gain curve after superposition of the curves a1 and b is c1, the frequency range f1~f nThe in-band gain is positive slope, the high frequency gain is high, and the low frequency gain is low; the slope adjustment circuit is configured by the digital control circuit, the gain curve adjustment is a2, the total gain curve of the radio frequency channel is c2, the gain positive slope is reduced, and the flatness is good; after m times of adjustment in the same direction, the gain curve adjustment of the slope adjustment circuit is a m , the total gain curve of the radio frequency channel is c m , and the gain flatness reaches the expectation, that is, the in-band gain fluctuation is less than the expected flatness threshold.

[0051] Based on the above-mentioned radio frequency transceiver gain flatness adaptive calibration circuit, the embodiment further proposes a radio frequency transceiver gain flatness adaptive calibration method, comprising:

[0052] The gain slope adjustment circuit adjusts the radio frequency channel gain flatness under the action of the digital control circuit; the power detection circuit detects the radio frequency signal power amplitude of the radio frequency channel output, the digital-to-analog conversion circuit converts the analog signal output by the power detection circuit into a digital signal, the digital control circuit obtains the radio frequency channel gain flatness according to the digital signal, and compares it with the expected flatness threshold, and controls the gain slope adjustment circuit to adjust the radio frequency channel gain flatness according to the comparison result; at the same time, the radio frequency signal generation circuit generates radio frequency signals of different frequencies and constant amplitudes as test signals input into the radio frequency channel.

[0053] Please refer to Figure 5 In this embodiment, specifically, a radio frequency transceiver gain flatness adaptive calibration method comprises the following specific steps:

[0054] Step S1: After calibration starts, the digital control circuit is initialized;

[0055] Step S2: Under the action of the digital control circuit output signal, the gain slope adjustment circuit initializes the radio frequency channel gain slope, and the radio frequency signal generation circuit outputs radio frequency signals with a frequency of f1 and a power of P0; a variable j is used to store the number of gain slope adjustments, and a variable i is used to store the number of times of input test signals and sampled output power at the current gain slope after each gain slope adjustment;

[0056] Step S3: The variable j is assigned a value of 1, the variable i is assigned a value of 1, and it is judged whether j is greater than m; at most m times of slope adjustment can be performed, and the radio frequency channel gain flatness test signal input, output power detection, digital-to-analog conversion, and saving of output radio frequency signal power amplitude information are performed after each slope adjustment;

[0057] Step S4: According to the judgment result, adaptive calibration is performed.

[0058] In this embodiment, specifically, the step S4 comprises:

[0059] When j is greater than m, it indicates that the gain flatness has not reached the expectation after m times of gain slope adjustment, at this time the flatness adjustment is ended, and the best flatness in the m times of slope adjustment process is taken as the final flatness adjustment result;

[0060] If j is less than or equal to m, j is increased by 1, and then it is judged whether i is greater than n, n being the frequency range f1-fn. n The number of inner test signal frequency points; if i is greater than n, it indicates that the radio frequency channel has completed n times of different frequency same power P0 test signal input, output power detection, digital-to-analog conversion, and saving of output radio frequency signal power amplitude information under the current gain slope, and the gain flatness and the gain slope can be calculated; if the gain flatness is less than the set flatness threshold, the algorithm is ended, and the current gain slope is the final gain slope for adjustment; if the expected gain flatness has not been reached, the digital control circuit outputs a signal to act on the gain slope adjustment circuit to adjust the gain slope of the radio frequency channel, and the radio frequency signal generation circuit generates n test signals of different frequencies and same power to input the radio frequency channel in turn, performs output power detection, digital-to-analog conversion, and saving of output radio frequency signal power amplitude information, re-calculates the gain flatness and the gain slope of the radio frequency channel, and judges again whether the gain slope of the radio frequency channel meets the requirements.

[0061] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the protection scope of the present application. It should be pointed out that for ordinary skilled persons in the art, without departing from the technical concept of the present application, a number of modifications and improvements can be made, which are within the protection scope of the present application.

[0062] This background section is provided to generally present the context of the application, the work of the current named inventors, the work described in this background section to the extent that it is described, and the work described in this section at the time of filing, neither expressly nor implicitly, is recognized as prior art of the present application.

Claims

1. A method for adaptively calibrating gain flatness of a radio frequency transceiver, characterized in that: A radio frequency transceiver gain flatness adaptive calibration circuit includes: The gain slope adjustment circuit adjusts the gain flatness of the RF channel under the action of the digital control circuit; the power detection circuit detects the power amplitude of the RF signal output by the RF channel, and the digital-to-analog conversion circuit converts the analog signal output by the power detection circuit into a digital signal. The digital control circuit obtains the gain flatness of the RF channel based on the digital signal and compares it with the desired flatness threshold. Based on the comparison result, the gain slope adjustment circuit is controlled to adjust the gain flatness of the RF channel, and the RF signal generation circuit is controlled to generate RF signals of different frequencies and constant amplitudes as test signals to be input into the RF channel. The specific steps include: Step S1: After calibration begins, the digital control circuit is initialized; Step S2: Under the action of the output signal of the digital control circuit, the gain slope adjustment circuit initializes the gain slope of the RF channel, and the RF signal generation circuit outputs an RF signal with a frequency of f1 and a power of P0; the variable j is used to store the number of gain slope adjustments, and the variable i is used to store the number of times the test signal is input and the output power is sampled at the current gain slope after each gain slope adjustment; Step S3: assigning a value of 1 to variable j and a value of 1 to variable i, and determining whether j is greater than m; a maximum of m slope adjustments can be performed, and each slope adjustment includes inputting a RF channel gain flatness test signal, detecting output power, performing digital-to-analog conversion, and storing output RF signal power amplitude information; Step S4: performing adaptive calibration according to the judgment result; A radio frequency transceiver gain flatness adaptive calibration circuit, comprising: Radio frequency signal generating circuit, digital control circuit, digital-to-analog conversion circuit, power detection circuit, gain slope adjustment circuit, first radio frequency circuit, second radio frequency circuit; The gain slope adjustment circuit is connected in series between the first RF circuit and the second RF circuit in the RF channel; the power detection circuit, the digital-to-analog conversion circuit, the digital control circuit, and the RF signal generation circuit are connected in series in sequence; the power detection circuit is connected to the RF output of the RF channel; the digital control circuit is connected to the gain slope adjustment circuit; and the RF signal generation circuit is connected to the RF input of the RF channel.

2. The method for adaptively calibrating gain flatness of a radio frequency transceiver according to claim 1, wherein: The step S4 comprises: When j is greater than m, it means that after m times of gain slope adjustment, the gain flatness still does not meet the expectation. At this time, the flatness adjustment is terminated and the best flatness during the m times of slope adjustment is used as the final flatness adjustment result. If j is less than or equal to m, increase j by 1, and then determine whether i is greater than n, where n is the frequency range f1~f n The number of internal test signal frequency points; if i is greater than n, it means that under the current gain slope, the RF channel has completed n times of P0 test signal input with different frequencies and the same power, output power detection, digital-to-analog conversion, and saved the output RF signal power amplitude information, and can calculate the gain flatness and gain slope. If the gain flatness is less than the set flatness threshold, the algorithm ends, and the current gain slope is the adjusted final gain slope; if the expected gain flatness is not achieved, the digital control circuit output signal acts on the gain slope adjustment circuit to adjust the RF channel gain slope, and at the same time controls the RF signal generation circuit to generate n test signals with different frequencies and the same power to input the RF channel in succession, perform output power detection, digital-to-analog conversion, and save the output RF signal power amplitude information, recalculate the RF channel gain flatness and gain slope, and judge again whether the RF channel gain slope meets the requirements.

3. The method for adaptively calibrating gain flatness of a radio frequency transceiver according to claim 1, wherein: The first RF circuit and the second RF circuit have RF signal processing functions.

4. The method for adaptively calibrating gain flatness of a radio frequency transceiver according to claim 3, wherein: The radio frequency signal processing function includes: One or more of the following functional units: attenuation, amplification, phase shifting, filtering, power combining / splitting, and mixing.

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