On-chip radio frequency signal processing circuit and transmission power calibration method

Abstract

The present invention provides an on-chip radio frequency signal processing circuit and a transmission power calibration method, which relates to the technical field of wireless communication, including a digital-to-analog converter, a low-pass filter, a mixer, a power amplifier, a self-calibration source and a transmitter signal strength indicator. The digital-to-analog converter, the low-pass filter and the mixer are connected in sequence, and the target baseband signal is low-pass filtered and up-mixed before inputting into the power amplifier. The power amplifier amplifies the mixed signal and then inputs into the transmitter signal strength indicator. The transmitter signal strength indicator calibrates the transmission power of the target baseband signal based on the constant power of the self-calibration source; the transmission power calibration method comprises the following steps: obtaining the constant power of the self-calibration source; based on the constant power, the transmitter signal strength indicator calibrates the transmission power in sections. The present invention can conveniently calibrate the transmission power of the chip one by one.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and in particular to an on-chip radio frequency signal processing circuit and a transmission power calibration method. Background Art

[0002] RF chips are mainly used for external communication of equipment, and the accuracy of RF chip transmission power needs to be controlled. In actual use, the transmission power of RF chips needs to be accurate to the nominal value ±1dBm or even 0.5dBm. However, due to factors such as device inconsistency, temperature changes, and device aging, even if they are based on the same platform and the same design, they will show different electrical properties. In order to eliminate this influence, these parameters will be measured before leaving the factory to obtain some parameter error data, and these error data will be stored. In actual use, these error data will be read and used to compensate the actual parameters to meet actual needs.

[0003] In the linear calibration of the RF chip transmission power, a complete calibration is performed from high power to low power on a specified channel to ensure that the device can accurately output the power levels required by the system and correct the nonlinearity of the wireless device output. This requires multiple tests, the establishment of a mathematical model, and the calibration of the device according to the mathematical model to find each device's own, more accurate power level output formula.

[0004] In the prior art, when calibrating the transmit power of a radio frequency chip, a spectrum analyzer is usually connected to the radio frequency chip, and the transmit power of the radio frequency chip is calibrated one by one using the spectrum analyzer. However, this process requires a certain amount of instrument calibration time, and the operation is relatively cumbersome, which is difficult to apply to the calibration of a large number of chips one by one. Therefore, it is necessary to develop a calibration circuit for the transmit power of a radio frequency chip, which can conveniently calibrate the chips one by one. Summary of the invention

[0005] The object of the present invention is to provide an on-chip radio frequency signal processing circuit and a transmission power calibration method, which can conveniently calibrate chips one by one.

[0006] In a first aspect, the present invention provides an on-chip radio frequency signal processing circuit, which adopts the following technical solution:

[0007] Includes a digital-to-analog converter, low-pass filter, mixer, power amplifier, self-calibration source, and transmitter signal strength indicator;

[0008] The input end of the digital-to-analog converter inputs a target baseband signal, the output end of the digital-to-analog converter is connected to a low-pass filter, and the target baseband signal includes an in-phase signal and an orthogonal signal;

[0009] The mixer is used to mix the in-phase signal and the quadrature signal filtered by the low-pass filter, and input the mixed mixed signal into the power amplifier;

[0010] The power amplifier amplifies the mixed signal and inputs the amplified mixed signal into the transmitter signal strength indicator;

[0011] The self-calibration source is used to generate a reference baseband signal of constant power and input the reference baseband signal to the transmitter signal strength indicator;

[0012] The transmitter signal strength indicator is provided with an M-level piecewise linear attenuation network, which is used to perform segmented calibration on the transmission power of the target baseband signal according to the constant power of the reference baseband signal;

[0013] The output value of the transmitter signal strength indicator indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator.

[0014] By adopting the above technical solution, the RF signal processing circuit is integrated into the RF chip. When calibrating the transmit power of the RF chip, there is no need for an external spectrum analyzer, which improves the convenience of calibrating the transmit power of the RF chip and reduces the cost of testing the chip after packaging.

[0015] When the signal processing circuit is working, the input end of the digital-to-analog converter is connected to the target baseband signal, the digital-to-analog converter converts the digital signal into an analog signal and outputs it to the low-pass filter, the low-pass filter performs low-pass filtering on the analog signal output by the digital-to-analog converter, and then inputs it to the mixer, the mixer mixes the in-phase signal and the orthogonal signal after low-pass filtering, and then outputs it to the power amplifier, the power amplifier amplifies the mixed signal, and then outputs it to the transmitter signal strength indicator, the segmented linear attenuation network in the transmitter signal strength indicator performs segmented calibration on the transmission power of the target baseband signal; the self-calibration source is used to generate a reference baseband signal with a constant power, and the constant power of the reference baseband signal is used as the reference power for the segmented calibration of the transmitter signal strength indicator.

[0016] Optionally, the on-chip radio frequency signal processing circuit further includes a transimpedance amplifier, a programmable gain amplifier and an analog-to-digital converter;

[0017] The transimpedance amplifier receives the calibration baseband signal, performs transimpedance amplification on the calibration baseband signal, and then inputs the transimpedance amplified calibration baseband signal into the programmable gain amplifier;

[0018] The programmable gain amplifier receives the calibration baseband signal after transimpedance amplification, performs operational amplification on the calibration baseband signal after transimpedance amplification, and inputs the calibration baseband signal after operational amplification to the analog-to-digital converter;

[0019] The analog-to-digital converter receives the calibration baseband signal after operational amplification, and the output value indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator.

[0020] By adopting the above technical solution, the transmitter signal strength indicator outputs a signal to the transimpedance amplifier. After the transimpedance amplifier performs transimpedance amplification on the output signal of the transmitter signal strength indicator, the programmable gain amplifier receives the output signal of the transimpedance amplifier, amplifies it, and outputs it through the analog-to-digital converter. The output of the analog-to-digital converter indicates the output signal strength of the transmitter signal strength indicator.

[0021] In a second aspect, the present invention provides a transmission power calibration method, comprising the following steps:

[0022] Obtaining a constant power of a reference baseband signal output by a self-calibration source;

[0023] Based on the constant power, the transmission power of the target baseband signal is calibrated in sections from large to small according to the M-level segmented linear attenuation network of the transmitter signal strength indicator.

[0024] By adopting the above technical solution, the constant power of the reference baseband signal output by the self-calibration source is obtained, the constant power is used as a reference, and the transmission power of the target baseband signal is aligned with the constant power according to the piecewise linear attenuation network in the transmitter signal strength indicator, and it is calibrated in multiple sections from high power to low power according to the piecewise linear attenuation network, which can improve the calibration accuracy of the target baseband signal transmission power and improve the linearity of the transmission power after calibration.

[0025] Optionally, when the constant power of the reference baseband signal from the self-calibration source is obtained, the attenuation of the attenuation network of the transmitter signal strength indicator is 0.

[0026] By adopting the above technical solution, when the constant power of the self-calibration source is obtained, the attenuation of the transmitter signal strength indicator attenuation network is pre-adjusted to 0, which can increase the temperature of the transmitter signal strength indicator output, which is beneficial to improve the alignment accuracy in the process of aligning the transmission power of the target baseband signal with the constant power.

[0027] Optionally, obtaining the constant power of the reference baseband signal of the self-calibration source includes: respectively obtaining the reference baseband signal of the transmitter signal strength indicator and the mixing signal of the power amplifier under the constant power of the self-calibration source, and outputting them as a first output value and a second output value respectively, and adjusting the mixing signal strength of the power amplifier so that the first output value is equal to the second output value, and at this time the constant power of the self-calibration source is equal to the output power of the power amplifier at the current mixing signal strength.

[0028] By adopting the above technical solution, when obtaining the constant power of the self-calibration source under the reference baseband signal, the reference baseband signal output by the self-calibration source under the constant power and the mixing signal of the power amplifier are respectively input into the transmitter signal strength indicator, and the transmitter signal strength indicator will output a first output value and a second output value, which are used to indicate the reference baseband signal strength and the mixing signal strength respectively; the mixing signal strength of the power amplifier is adjusted so that the first output value and the second output value are equal, and at this time the constant power of the self-calibration source is equal to the output power of the power amplifier under the current mixing signal strength. Thus, the constant power of the reference baseband signal output by the self-calibration source is obtained.

[0029] Optionally, the step of obtaining the constant power of the reference baseband signal output from the self-calibration source comprises the following steps:

[0030] S110, the transmitter signal strength indicator receives a reference baseband signal of the self-calibration source at a constant power, and the output of the transmitter signal strength indicator is a first output value;

[0031] S120, the transmitter signal strength indicator receives the mixing signal of the power amplifier, and the output of the transmitter signal strength indicator is a second output value;

[0032] S130. Adjust the signal strength of the mixing signal output by the power amplifier until the second output value is equal to the first output value, and the constant power of the self-calibration source is equal to the output power of the power amplifier at the current mixing signal strength.

[0033] By adopting the above technical solution, when obtaining the constant power of the self-calibration source under the reference baseband signal, the reference baseband signal output by the self-calibration source under the constant power is input to the transmitter signal strength indicator in advance, and the transmitter signal strength indicator receives and outputs it as a first output value, and the first output value indicates the strength of the reference baseband signal; then the mixing signal of the power amplifier is input to the transmitter signal strength indicator, and the transmitter signal strength indicator outputs it as a second output value, and the second output value indicates the strength of the mixing signal; the signal strength of the mixing signal output by the power amplifier is adjusted, thereby adjusting the second output value so that the second output value is equal to the first output value, and at this time, the output power of the power amplifier when outputting the current mixing signal is equal to the constant power of the self-calibration source. Thus, the constant power of the reference baseband signal output by the self-calibration source is obtained.

[0034] Optionally, in S110, the transmitter signal strength indicator and the self-calibration source are in working state, and the power amplifier is turned off; in S120, the transmitter signal strength indicator and the power amplifier are in working state, and the self-calibration source is turned off.

[0035] Optionally, in S110, before the self-calibration source operates, a DC offset correction is performed on the transmitter signal strength indicator.

[0036] Optionally, the constant power-based, M-level piecewise linear attenuation network of the transmitter signal strength indicator is used to calibrate the transmission power of the target baseband signal from large to small in sections, including:

[0037] Based on the constant power, adjusting the output power of the power amplifier to be a reference power, wherein there is a deviation between the reference power and the constant power, and the deviation is less than 1%;

[0038] The attenuation network of the transmitter signal strength indicator is adjusted in sequence from large to small attenuation degrees to linearly reduce the output power of the power amplifier, and the transmitter signal strength indicator performs segmented adjustment on the transmission power of the target baseband signal from large to small;

[0039] The output value of the transmitter signal strength indicator indicates the calibration signal baseband strength; the linearly reduced output power of the power amplifier corresponds to the output value of the transmitter signal strength indicator to form a linear calibration function.

[0040] By adopting the above technical solution, when the transmission power of the target baseband signal is calibrated in sections, based on the constant power of the self-calibration source, the output power of the power amplifier is adjusted to the reference power, the strength of the mixed signal output by the power amplifier is the signal strength output under the reference power, and the deviation between the reference power and the constant power is less than 1%; with the reference power as the maximum power for linear calibration, segmented calibration is performed according to the segmented attenuation network of the transmitter signal strength indicator; the output power of the power amplifier is gradually reduced, so that the output value of the transmitter signal strength indicator is correspondingly reduced, and at this time, the output power of the power amplifier and the output value of the transmitter signal strength indicator form a linear calibration function.

[0041] Optionally, the constant power-based, M-level piecewise linear attenuation network of the transmitter signal strength indicator is used to calibrate the transmission power of the target baseband signal from large to small in sections, including the following steps:

[0042] S210, the self-calibration source and the transmitter signal strength indicator work, adjusting the attenuation degree of the attenuation network of the transmitter signal strength indicator to a maximum gear; the transmitter signal strength indicator receives a reference signal output by the self-calibration source at a reference power, the reference signal is attenuated by the transmitter signal strength indicator, the output of the transmitter signal strength indicator indicates the strength of the reference signal after attenuation, and outputs it as a third output value;

[0043] S220, the self-calibration source is turned off, the power amplifier is turned on, and the attenuation degree of the attenuation network of the transmitter signal strength indicator is kept at a maximum value; the transmitter signal strength indicator receives the mixing signal output by the power amplifier, the transmitter signal strength indicator outputs the attenuated mixing signal, and the transmitter signal strength indicator outputs the attenuated mixing signal as a fourth output value;

[0044] S230, adjusting the signal strength of the mixing signal output by the power amplifier until the fourth output value is equal to the third output value, and the output power of the current mixing signal strength output by the power amplifier is equal to the sum of the reference power and the balun loss;

[0045] S240. Adjust the attenuation degree of the attenuation network of the transmitter signal strength indicator from large to small in sequence, and gradually reduce the mixed signal strength output by the power amplifier within the linear range of each attenuation network. The output value of the transmitter signal strength indicator and the output power of the power amplifier output corresponding to the mixed signal strength form a multi-segment linear calibration function.

[0046] By adopting the above technical solution, when the transmission power of the target baseband signal is calibrated in sections, the attenuation degree of the attenuation network of the transmitter signal strength indicator is pre-adjusted to the maximum gear, the self-calibration source outputs the reference signal at the reference power, and the transmitter signal strength indicator receives the reference signal and then attenuates and outputs it as a third output value; the self-calibration source is turned off, the power amplifier is turned on, the power amplifier inputs the mixing signal to the transmitter signal strength indicator, and the transmitter signal strength indicator receives the mixing signal and then attenuates and outputs it as a fourth output value; the signal strength of the mixing signal output by the power amplifier is adjusted so that the fourth output value is equal to the third output value, and the output power of the power amplifier is equal to the sum of the reference power and the balun loss; the output power of the power amplifier at this time is taken as the maximum power, the attenuation degree of the attenuation network of the transmitter signal strength indicator is adjusted in sequence from large to small, and the output power of the power amplifier is gradually reduced within the linear range of each attenuation network, and the output value of the transmitter signal strength indicator corresponds to the output power of the power amplifier, thereby forming a multi-segment linear calibration function.

[0047] The on-chip radio frequency signal processing circuit and the transmission power calibration method provided by the present invention have at least one of the following beneficial technical effects:

[0048] (1) By integrating the RF signal processing circuit into the RF chip, there is no need to connect an external spectrum analyzer when calibrating the transmit power of the RF chip. This can reduce the testing cost after chip packaging and improve the efficiency of calibrating each chip one by one.

[0049] (2) By setting a transmitter signal strength indicator in the calibration circuit, and the transmitter signal strength indicator is provided with an M-level segmented linear attenuation network, the transmission power of the radio frequency can be segmentedly calibrated from high power to low power according to these segmented attenuation networks, and a corresponding linear calibration function can be obtained;

[0050] (3) When performing segmented calibration of the transmit power, first obtain the output power of the self-calibration source, use the output power of the self-calibration source as the reference power, and calibrate the transmit power segment by segment based on the segmented linear interval in the transmitter signal strength indicator attenuation network, thereby improving the accuracy and convenience of the transmit power calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a structural diagram of an on-chip radio frequency signal processing circuit in an embodiment of the present invention;

[0052] Figure 2 is a schematic structural diagram of an on-chip radio frequency signal processing circuit in an embodiment of the present invention;

[0053] Figure 3 is a flow chart of a transmit power calibration method in an embodiment of the present invention;

[0054] Figure 4 is a flow chart of S100 in the transmit power calibration method in an embodiment of the present invention;

[0055] Figure 5 is a flow chart of S200 in the transmit power calibration method in an embodiment of the present invention;

[0056] Figure 6 It is a linear calibration coordinate diagram of the transmit power calibration method in an embodiment of the present invention.

[0057] Description of reference numerals:

[0058] 1. Digital-to-analog converter; 2. Low-pass filter; 3. Mixer; 4. Power amplifier; 5. Transmitter signal strength indicator; 6. Self-calibration source; 7. Transimpedance amplifier; 8. Programmable gain amplifier; 9. Analog-to-digital converter. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0060] An embodiment of the present invention provides an on-chip radio frequency signal processing circuit.

[0061] Reference Figure 1 and Figure 2 , the on-chip RF signal processing circuit includes a digital to analog converter 1 (Digital to Analog Converter, DAC), a low-pass filter 2 (Low-Pass Filter, LPF), a mixer 3, a power amplifier 4 (Power Amplifier, PA) and a transmitter signal strength indicator 5 (Transmitter Signal Strength Indication, TSSI).

[0062] Reference Figure 1 and Figure 2, the target baseband signal is input into the input end of the digital-to-analog converter 1. The target baseband signal is the signal to be calibrated output by the RF chip. The target baseband signal includes an in-phase signal and an orthogonal signal. The digital-to-analog converter 1 converts the digital signal into an analog signal, and outputs the analog signal to the low-pass filter 2. The low-pass filter 2 performs low-pass filtering on the in-phase signal and the orthogonal signal after the digital-to-analog conversion, and then inputs them into the mixer 3. The mixer 3 mixes the in-phase signal and the orthogonal signal after the low-pass filtering, and inputs the mixed signal into the power amplifier 4. After receiving the mixed signal, the power amplifier 4 amplifies the mixed signal, and inputs the amplified mixed signal into the transmitter signal strength indicator 5.

[0063] The transmitter signal strength indicator 5 is provided with an M-level segmented linear attenuation network, and the attenuation network (Transmitter Signal Strength Indication Attenuation, TSSI-Att) of the transmitter signal strength indicator 5 is used to perform segmented calibration on the transmission power of the target baseband signal. In the embodiment of the present invention, the transmitter signal strength indicator 5 is provided with a three-level segmented linear attenuation network, which are 00 level, 01 level and 11 level, respectively, and the attenuation degree of 00 level, 01 level and 11 level increases from zero in sequence; in some other embodiments, the transmitter signal strength indicator 5 can also be provided with a four-level segmented linear attenuation network, which are 00 level, 01 level, 10 level and 11 level, respectively, and the attenuation degree of 00 level, 01 level, 10 level and 11 level increases from zero in sequence.

[0064] Reference Figure 1 and Figure 2 The on-chip RF signal processing circuit also includes a self-calibration source 6 (Self Calibration Source, SCS), which is connected to the transmitter signal strength indicator 5. The self-calibration source 6 is used to output a reference baseband signal to the transmitter signal strength indicator 5. The transmitter signal strength indicator 5 performs segmented calibration on the transmission power of the target baseband signal based on the constant power when the self-calibration source 6 outputs the reference baseband signal as a reference.

[0065] Reference Figure 1 and Figure 2The on-chip RF signal processing circuit also includes a trans-impedance amplifier 7 (Trans-Impedance Amplifier, TIA), a programmable gain amplifier 8 (Programmable Gain Amplifier, PGA) and an analog to digital converter 9 (Analog to Digital Converter, ADC). The trans-impedance amplifier 7 receives the signal output by the transmitter signal strength indicator 5 and performs trans-impedance amplification on it. The programmable gain amplifier 8 receives the signal output by the trans-impedance amplifier 7 and performs operational amplification on it. The analog to digital converter 9 receives the output signal of the programmable gain amplifier 8 and converts the analog signal into a digital signal. The output value of the analog to digital converter 9 indicates the output signal strength of the transmitter signal strength indicator 5.

[0066] Reference Figures 3 to 6 The embodiment of the present invention further provides a transmission power calibration method, which is applied to the above-mentioned on-chip radio frequency signal processing circuit, and includes the following steps:

[0067] S100, obtaining a constant power of a reference baseband signal output from the calibration source 6:

[0068] S110, the transmitter signal strength indicator 5 is enabled, and after DC offset cancellation (DCOC) is performed on the transmitter signal strength indicator 5, the attenuation network of the transmitter signal strength indicator 5 is adjusted to level 00, the power amplifier 4 is in a closed state, the self-calibration source 6 is turned on, and the gain of the programmable gain amplifier 8 is adjusted to 0dB; the self-calibration source 6 outputs a reference baseband signal at its own constant power, and the transmitter signal strength indicator 5 receives the reference baseband signal output by the self-calibration source 6, and the output signal of the transmitter signal strength indicator 5 passes through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence, and is output as D-SCS; D-SCS indicates the signal strength of the reference baseband signal output by the self-calibration source 6 at constant power;

[0069] S120, turn off the self-calibration source 6, turn on the power amplifier 4, keep the attenuation network of the transmitter signal strength indicator 5 at 00 gear, and keep the gain of the programmable gain amplifier 8 at 0dB; the digital-to-analog converter 1, the low-pass filter 2 and the mixer 3 perform digital-to-analog conversion, low-pass filtering and mixing on the target baseband signal, and then input it to the power amplifier 4, the transmitter signal strength indicator 5 receives the mixed signal amplified by the power amplifier 4, and the output signal of the transmitter signal strength indicator 5 passes through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence, and then outputs it as D-PA; the D-PA indicates the strength of the mixed signal input to the transmitter signal strength indicator 5 by the power amplifier 4;

[0070] S130, adjusting the amplification factor of the power amplifier 4, thereby changing the signal strength of the mixed signal output by the power amplifier 4, until D-PA is equal to D-SCS, at which time the signal strength of the mixed signal output by the power amplifier 4 is equal to the reference baseband signal strength output by the self-calibration source 6 at a constant power, and thus the constant power of the self-calibration source 6 is equal to the output power of the power amplifier 4 at this time;

[0071] S200, based on the constant power of the self-calibration source 6 and according to the three-stage piecewise linear attenuation network in the transmitter signal strength indicator 5, the transmission power of the target baseband signal is calibrated in three stages:

[0072] S210, the transmitter signal strength indicator 5 is enabled, and the attenuation network of the transmitter signal strength indicator 5 is adjusted to level 11, where level 11 is the maximum attenuation level of the attenuation network of the transmitter signal strength indicator 5, the power amplifier 4 is in a closed state, and the self-calibration source 6 is turned on; the self-calibration source 6 outputs a reference signal at a reference power, the transmitter signal strength indicator 5 receives the reference signal, and attenuates the reference signal, and the output attenuated reference signal passes through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence, and is output as D-SCS-ATT-11; D-SCS-ATT-11 indicates the output signal strength of the transmitter signal strength indicator 5 under the reference signal and when the attenuation network is level 11; wherein, there is a deviation between the reference power of the self-calibration source 6 and the constant power, and the deviation is less than 1%;

[0073] S220, turn off the self-calibration source 6, turn on the power amplifier 4, and keep the attenuation network of the transmitter signal strength indicator 5 at level 11; the target baseband signal passes through the digital-to-analog converter 1, the low-pass filter 2 and the mixer 3 in sequence, and the mixed signal is input into the power amplifier 4, the power amplifier 4 amplifies the mixed signal, and the transmitter signal strength indicator 5 receives the mixed signal amplified by the power amplifier 4. After attenuation by the attenuation network, the output of the transmitter signal strength indicator 5 passes through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence, and the output is D-PA-ATT-11;

[0074] S230, adjusting the amplification factor of the power amplifier 4, thereby changing the signal strength of the mixing signal output by the power amplifier 4, until D-PA-ATT-11 is equal to D-SCS-ATT-11, at which time the output power of the mixing signal strength output by the power amplifier 4 is equal to the sum of the reference power of the self-calibration source 6 and the balun loss; at this time, the output power of the power amplifier 4 is recorded as PRF-0;

[0075] S240, maintaining the attenuation network of the transmitter signal strength indicator 5 at level 11, gradually reducing the output power of the power amplifier 4 at intervals of 0.5 dBm, when the output power of the power amplifier 4 is reduced to the linear boundary value of the attenuation network level 11 of the transmitter signal strength indicator 5, the output power of the power amplifier 4 at this time is recorded as PRF-1; the output value of the signal output by the transmitter signal strength indicator 5 after passing through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence corresponds to the output power of the power amplifier 4, and after linear fitting, a linear calibration function between PRF-1 and PRF-0 is obtained;

[0076] S250, maintaining the output power of the power amplifier 4 at PRF-1, adjusting the attenuation network of the transmitter signal strength indicator 5 to level 01, and gradually reducing the output power of the power amplifier 4 at intervals of 0.5 dBm. When the output power of the power amplifier 4 is reduced to the linear boundary value of the attenuation network of the transmitter signal strength indicator 5 at level 01, the output power of the power amplifier 4 at this time is recorded as PRF-2; the output value of the signal output by the transmitter signal strength indicator 5 after passing through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence corresponds to the output power of the power amplifier 4. After linear fitting, a linear calibration function between PRF-2 and PRF-1 is obtained;

[0077] S260, maintain the output power of the power amplifier 4 at PRF-2, adjust the attenuation network of the transmitter signal strength indicator 5 to level 00, gradually reduce the output power of the power amplifier 4 at intervals of 0.5 dBm, and obtain PRF-3; the output value of the signal output by the transmitter signal strength indicator 5 after passing through the transimpedance amplifier 7, the programmable gain amplifier 8 and the analog-to-digital converter 9 in sequence corresponds to the output power of the power amplifier 4, and after linear fitting, a linear calibration function between PRF-3 and PRF-2 is obtained.

[0078] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. An on-chip radio frequency signal processing circuit, It is characterized in that include: digital-to-analog converters, low-pass filters, mixers, power amplifiers, self-calibration sources, and transmitter signal strength indicators; The input end of the digital-to-analog converter inputs a target baseband signal, the output end of the digital-to-analog converter is connected to a low-pass filter, and the target baseband signal includes an in-phase signal and an orthogonal signal; The mixer is used to mix the in-phase signal and the quadrature signal filtered by the low-pass filter, and input the mixed mixed signal into the power amplifier; The power amplifier amplifies the mixed signal and inputs the amplified mixed signal into the transmitter signal strength indicator; The self-calibration source is used to generate a reference baseband signal of constant power and input the reference baseband signal to the transmitter signal strength indicator; The transmitter signal strength indicator is provided with an M-level piecewise linear attenuation network, and the attenuation degree of the M-level piecewise linear attenuation network is from large to small when calibrating the transmission power of the target baseband signal. The transmitter signal strength indicator is based on the constant power of the reference baseband signal, and according to the M-level piecewise linear attenuation network, the transmission power of the target baseband signal is segmented and calibrated from large to small, specifically including: based on the constant power, adjusting the output power of the power amplifier to the reference power, and there is a deviation between the reference power and the constant power, and the deviation is less than 1%; adjusting the attenuation network of the transmitter signal strength indicator in sequence from large to small in attenuation degree, linearly reducing the output power of the power amplifier, and the transmitter signal strength indicator performs segmented adjustment on the transmission power of the target baseband signal from large to small; the output value of the transmitter signal strength indicator indicates the calibration signal baseband strength; the output power of the power amplifier after linear reduction corresponds to the output value of the transmitter signal strength indicator to form a linear calibration function; an output value of the transmitter signal strength indicator indicating the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator; Among them, the reference baseband signal of the transmitter signal strength indicator and the mixing signal of the power amplifier under the constant power of the self-calibration source are obtained respectively, and output as the first output value and the second output value respectively, and the mixing signal strength of the power amplifier is adjusted so that the first output value is equal to the second output value, and the constant power of the self-calibration source is obtained according to the output power of the power amplifier at the current mixing signal strength.

2. The on-chip radio frequency signal processing circuit according to claim 1, It is characterized in that The on-chip radio frequency signal processing circuit also includes a transimpedance amplifier, a programmable gain amplifier and an analog-to-digital converter; The transimpedance amplifier receives the calibration baseband signal, performs transimpedance amplification on the calibration baseband signal, and then inputs the transimpedance amplified calibration baseband signal into the programmable gain amplifier; The programmable gain amplifier receives the calibration baseband signal after transimpedance amplification, performs operational amplification on the calibration baseband signal after transimpedance amplification, and inputs the calibration baseband signal after operational amplification to the analog-to-digital converter; The analog-to-digital converter receives the calibration baseband signal after operational amplification, and the output value indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator.

3. A transmission power calibration method, the method being applied to the on-chip radio frequency signal processing circuit as claimed in any one of claims 1 to 2, It is characterized in that The following steps are involved: Obtaining a constant power of a reference baseband signal output by a self-calibration source; Based on the constant power, the transmission power of the target baseband signal is calibrated in sections from large to small according to the M-level segmented linear attenuation network of the transmitter signal strength indicator.

4. The transmission power calibration method according to claim 3, It is characterized in that When the constant power of the reference baseband signal from the calibration source is obtained, the attenuation of the attenuation network of the transmitter signal strength indicator is zero.

5. The transmission power calibration method according to claim 3, It is characterized in that The method of obtaining the constant power of the reference baseband signal output by the self-calibration source comprises the following steps: S110, the transmitter signal strength indicator receives a reference baseband signal of the self-calibration source at a constant power, and the output of the transmitter signal strength indicator is a first output value; S120, the transmitter signal strength indicator receives the mixing signal of the power amplifier, and the output of the transmitter signal strength indicator is a second output value; S130. Adjust the signal strength of the mixing signal output by the power amplifier until the second output value is equal to the first output value, and the constant power of the self-calibration source is equal to the output power of the power amplifier at the current mixing signal strength.

6. The transmission power calibration method according to claim 5, It is characterized in that In the S110, the transmitter signal strength indicator and the self-calibration source are in working state, and the power amplifier is turned off; in the S120, the transmitter signal strength indicator and the power amplifier are in working state, and the self-calibration source is turned off.

7. The transmission power calibration method according to claim 6, It is characterized in that In the S110, before the self-calibration source operates, a DC offset correction is performed on the transmitter signal strength indicator.

8. The transmission power calibration method according to claim 3, It is characterized in that The method comprises the following steps: based on constant power, and according to the M-level segmented linear attenuation network of the transmitter signal strength indicator, calibrating the transmission power of the target baseband signal from large to small segmented. S210, the self-calibration source and the transmitter signal strength indicator work, adjusting the attenuation degree of the attenuation network of the transmitter signal strength indicator to a maximum gear; the transmitter signal strength indicator receives a reference signal output by the self-calibration source at a reference power, the reference signal is attenuated by the transmitter signal strength indicator, the output of the transmitter signal strength indicator indicates the strength of the reference signal after attenuation, and outputs it as a third output value; S220, the self-calibration source is turned off, the power amplifier is turned on, and the attenuation degree of the attenuation network of the transmitter signal strength indicator is maintained at a maximum value; the transmitter signal strength indicator receives the mixing signal output by the power amplifier, the transmitter signal strength indicator outputs the attenuated mixing signal, and the transmitter signal strength indicator outputs the attenuated mixing signal as a fourth output value; S230, adjusting the signal strength of the mixing signal output by the power amplifier until the fourth output value is equal to the third output value, and the output power of the current mixing signal strength output by the power amplifier is equal to the sum of the reference power and the balun loss; S240. Adjust the attenuation degree of the attenuation network of the transmitter signal strength indicator from large to small in sequence, and gradually reduce the mixed signal strength output by the power amplifier within the linear range of each attenuation network. The output value of the transmitter signal strength indicator and the output power of the power amplifier output corresponding to the mixed signal strength form a multi-segment linear calibration function.

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