Receiving gain compensation circuit and receiving gain compensation method of radio frequency chip

Abstract

The present invention provides a receiving gain compensation circuit and receiving gain compensation method for a radio frequency chip. The receiving gain compensation circuit includes a digital-to-analog converter, a transmitting filter, a transmitting mixer, a power amplifier, a converter, a low-noise power amplifier, a receiving mixer, a receiving filter and an analog-to-digital converter, and a gain compensation subcircuit through which a target baseband signal passes in sequence; the gain compensation circuit generates a digital compensation signal under a compensation power, and superimposes the digital compensation signal on the output of the analog-to-digital converter to obtain a preset signal; the compensation power is equal to the difference between the transmitting power under the target baseband signal and the receiving power of the reference signal output by the analog-to-digital converter; the receiving gain compensation method includes the following steps: obtaining the compensation power; the gain compensation subcircuit outputs the digital compensation signal under the compensation power and superimposes it on the digital signal output by the analog-to-digital converter to obtain a preset signal. The present invention can conveniently compensate the receiving gain of the radio frequency chip one by one.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and in particular to a receiving gain compensation method of a radio frequency chip and a receiving gain compensation method. Background Art

[0002] RF chips are mainly used for external communication of equipment, and the accuracy of RF chip receiving gain needs to be controlled. In actual use, the receiving gain of RF chips needs to be accurate to within ±1dB or even ±0.5dB of the nominal value. However, due to factors such as device inconsistency, temperature changes, device aging, external interference, etc., 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 for errors to meet actual needs.

[0003] The existing RF receiving gain calibration preprocessing method includes fast AGC (Automatic Gain Control) calibration technology, which takes the middle channel of the frequency band for testing, fixes the instrument output power (Cell Power), and continuously adjusts the gain (Gain) of the AGC circuit to make the RSSI (Received Signal Strength Indication) reach the target value, and then changes the Cell Power on the instrument side to make the measured RSSI equal to the Cell Power. In short, it is to test two or more points in a gain range of the AGC circuit, calculate a fixed gain slope, and participate in linear calculation operations to obtain the Gain sequence.

[0004] Therefore, in the prior art, when calibrating the receiving gain of the RF chip, it is necessary to connect a spectrum analyzer and a stable signal source to the RF chip, and use the spectrum analyzer to calibrate the receiving gain of the RF in sections. However, this calibration process requires a certain amount of instrument calibration time, and the operation is relatively cumbersome, which is difficult to apply to the calibration of large quantities of chips one by one. Therefore, it is necessary to develop a compensation circuit for the receiving gain of the RF chip, which can conveniently compensate the receiving gain of the RF chip one by one. Summary of the invention

[0005] The object of the present invention is to provide a receiving gain compensation circuit and a receiving gain compensation method for a radio frequency chip, which are used to compensate the receiving gain of the radio frequency chip and can conveniently compensate the receiving gain of a large number of radio frequency chips one by one.

[0006] In a first aspect, the present invention provides a receiving gain compensation circuit of a radio frequency chip, which adopts the following technical solution:

[0007] It includes a digital-to-analog converter, a transmit filter, a transmit mixer, a power amplifier, a converter, a low-noise power amplifier, a receive mixer, a receive filter, an analog-to-digital converter, and a gain compensation subcircuit;

[0008] The input end of the digital-to-analog converter is connected to the target baseband signal, and the output end of the digital-to-analog converter is connected to the transmit filter, and the target baseband signal includes an in-phase signal and an orthogonal signal; the transmit filter performs low-pass filtering on the target baseband signal and outputs it as a filtered signal, and inputs the filtered signal into the transmit mixer; the transmit mixer performs up-conversion on the filtered signal and outputs it as an up-converted signal, and inputs the up-converted signal into the power amplifier;

[0009] The power amplifier amplifies the up-converted signal, and outputs the amplified up-converted signal in a differential manner, and inputs the differential signal into the converter; the converter comprises a primary winding and a differential secondary winding, the primary winding is coupled to the input end of the low-noise power amplifier, and the differential secondary winding is coupled to the output end of the power amplifier; the converter is used to output the differential signal as a primary signal;

[0010] The low noise power amplifier receives the primary signal, amplifies the primary signal and inputs it into the receiving mixer; the receiving mixer down-converts the amplified primary signal and outputs it as a down-converted signal, and inputs the down-converted signal into the receiving filter; the receiving filter filters the down-converted signal and outputs it as a standard signal, and inputs the standard signal into the analog-to-digital converter, and the analog-to-digital converter outputs the reference signal receiving power;

[0011] The gain compensation subcircuit generates a digital compensation signal at a compensation power, and superimposes the digital compensation signal on the output of the analog-to-digital converter to obtain a preset signal; the compensation power is equal to the difference between the transmission power of the target baseband signal and the receiving power of the reference signal.

[0012] By adopting the above technical solution, the digital-to-analog converter is connected to the target baseband signal, the digital signal is converted into an analog signal, the transmitting filter performs low-pass filtering on the signal output by the digital-to-analog converter, and transmits the filtered signal to the transmitting mixer, the transmitting mixer mixes the two signals and performs up-conversion, the up-converted signal is input to the power amplifier, the power amplifier amplifies the signal, and differentially outputs it to the converter, the converter converts the differential output into a primary signal, and the primary signal is input to the low-noise power amplifier for gain amplification, the signal amplified by the low-noise power amplifier is successively down-converted by the receiving mixer and filtered by the end filter, and then output as a standard signal, the analog-to-digital converter converts the standard signal from an analog signal to a digital signal; the digital compensation signal of the gain compensation subcircuit under the compensation power is superimposed on the output of the analog-to-digital converter, so that the digital compensation signal and the output signal of the analog-to-digital converter are superimposed to obtain a preset signal; the compensation power is equal to the difference between the transmission power of the target baseband signal and the reference signal receiving power of the signal output by the analog-to-digital converter.

[0013] Its beneficial effects are: since the gain compensation subcircuit outputs a digital compensation signal, the digital signal is adjusted with good linearity, and at the same time, the difference between the transmission power of the target baseband signal and the reference signal receiving power of the output signal of the analog-to-digital converter is compared, and the deviation value is calculated, and the deviation value is used as the compensation value of the entire receiver system under the current transmission power and current gain, thereby obtaining a preset signal within the receiver preset; the receiving gain of each RF chip can be compensated one by one, and the accuracy of the compensated signal is improved.

[0014] Optionally, the receiving gain compensation circuit further includes a transmitter signal strength indicator and a self-calibration source;

[0015] The power amplifier also inputs the differential signal into the transmitter signal strength indicator;

[0016] 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;

[0017] The transmitter signal strength indicator is provided with an M-level piecewise linear attenuation network, which is used to perform piecewise calibration on the target baseband signal according to the constant power of the reference baseband signal;

[0018] 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.

[0019] By adopting the above technical solution, the beneficial effect is that the transmit power can be calibrated first, and the receive gain of the RF chip can be calibrated using the calibrated transmit power.

[0020] Optionally, the receiving filter receives the calibration baseband signal output by the transmitter signal strength indicator, and performs low-pass filtering on the calibration baseband signal before inputting the signal into the analog-to-digital converter;

[0021] The output value of the analog-to-digital converter indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator.

[0022] By adopting the above technical solution, the beneficial effect is that when calibrating the transmission power of the RF chip, the output value of the analog-to-digital converter indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator, so that the transmission frequency after calibration of the transmitter signal strength indicator starts from the constant power of the self-calibration source.

[0023] Optionally, the converter is a balun converter, the primary winding of the balun converter is a single-ended winding, and the balun converter inputs a single-ended signal to the low-noise power amplifier.

[0024] By adopting the above technical solution, the beneficial effect is that the balun converter performs single-ended conversion on the differential signal and outputs it.

[0025] Optionally, the differential secondary winding of the balun transformer receives the differential signal output by the power amplifier.

[0026] Optionally, the gain compensation sub-circuit is integrated in the SOC of the radio frequency chip.

[0027] By adopting the above technical solution, the beneficial effect is that the gain compensation sub-circuit is integrated into the SOC, so that the receiving gain can be compensated within the radio frequency chip.

[0028] In a second aspect, the present invention provides a receiving gain compensation method for a radio frequency chip, comprising the following steps:

[0029] Obtaining compensation power;

[0030] The gain compensation subcircuit obtains a digital compensation signal at the compensation power based on the compensation power;

[0031] The digital compensation signal is superimposed on the digital signal output by the analog-to-digital converter to obtain a preset signal.

[0032] By adopting the above technical solution, the beneficial effect is that when compensating the gain, the compensation power is first obtained, and the gain compensation subcircuit outputs a digital compensation signal under the compensation power, and the digital compensation signal is superimposed with the digital signal output by the analog-to-digital converter to obtain a preset signal.

[0033] Optionally, before obtaining the compensation power, the following steps are also included:

[0034] Obtain the transmission power of the target baseband signal;

[0035] Obtaining a reference signal received power output by the analog-to-digital converter;

[0036] The compensation power is obtained based on the transmit power and the reference signal received power.

[0037] By adopting the above technical solution, the beneficial effect is that when obtaining the compensation power, the transmission power of the input target baseband signal and the reference signal receiving power output by the analog-to-digital converter are first obtained, and the difference between the transmission power and the reference signal receiving power is calculated, and the difference is the compensation power.

[0038] Optionally, before obtaining the transmission power of the target baseband signal, the following steps are also included:

[0039] Calibrate the transmit power of the RF chip.

[0040] By adopting the above technical solution, the beneficial effect is that before calibrating the receiving gain of the RF chip, the transmitting power of the RF chip can be calibrated first, and then the receiving gain can be calibrated based on the calibrated transmitting power. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is a circuit structure diagram of a receiving gain compensation circuit of a radio frequency chip in an embodiment of the present invention;

[0042] Figure 2 is a schematic structural diagram of a receiving gain compensation circuit in an embodiment of the present invention;

[0043] Figure 3 is a schematic diagram of a process for calibrating transmit power in an embodiment of the present invention;

[0044] Figure 4 is a schematic diagram of a flow chart of step S100 of calibrating the transmit power in an embodiment of the present invention;

[0045] Figure 5 is a schematic diagram of a flow chart of step S200 of calibrating the transmit power in an embodiment of the present invention;

[0046] Figure 6 A linear calibration coordinate diagram after calibrating the transmit power in an embodiment of the present invention;

[0047] Figure 7 is a flow chart of a receiving gain compensation method in an embodiment of the present invention;

[0048] Figure 8 It is a flowchart of a receiving gain compensation method in an embodiment of the present invention.

[0049] Description of reference numerals:

[0050] 1. Digital-to-analog converter; 2. Transmit filter; 3. Transmit mixer; 4. Power amplifier; 5. Converter; 51. Primary winding; 52. Differential secondary winding; 6. Low noise power amplifier; 7. Receive mixer; 8. Receive filter; 9. Analog-to-digital converter; 10. Gain compensation subcircuit; 11. Digitally controlled programmable gain amplifier; 12. Bonding line; 13. Transmitter signal strength indicator; 14. Self-calibration source. DETAILED DESCRIPTION

[0051] 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.

[0052] An embodiment of the present invention provides a receiving gain compensation circuit for a radio frequency chip.

[0053] Reference Figure 1 and Figure 2 The receiving gain compensation circuit of the RF chip shown includes a digital to analog converter 1 (Digital to Analog Converter, DAC), a transmit filter 2 (RX Filter), a transmit mixer 3 (RX Mixer), a power amplifier 4 (Power Amplifier, PA), a converter 5, a low noise power amplifier 64 (Low Noise Amplifier, LNA), a receive mixer 7 (TX Mixer), a receive filter 8 (TX Filter), an analog to digital converter 9 (Analog to Digital Converter, DAC) and a gain compensation sub-circuit 10 (DFE Gain Module).

[0054] The input end of the digital-to-analog converter 1 is connected to the target baseband signal, which includes an in-phase signal and an orthogonal signal. The digital-to-analog converter 1 converts the target baseband signal from a digital signal to an analog signal and then inputs the converted signal into the transmitting filter 2. The transmitting filter 2 performs a low-pass filter on the target baseband signal after the digital-to-analog conversion to obtain a filtered signal.

[0055] In some embodiments, reference Figure 1 and Figure 2 The input end of the digital-to-analog converter 1 is provided with a digital variable gain amplifier 11 (DVGA). The input end of the digital variable gain amplifier 11 is connected to the target baseband signal including the in-phase signal and the orthogonal signal, and after digital gain amplification, the digital target baseband signal after gain amplification is input into the digital-to-analog converter 1.

[0056] The transmit filter 2 inputs the filtered signal into the transmit mixer 3, the transmit mixer 3 up-converts the filtered signal and outputs it as an up-converted signal, the transmit mixer 3 inputs the up-converted signal into the power amplifier 4, the power amplifier 4 amplifies the gain of the up-converted signal, and outputs it as a differential signal, and inputs the differential signal into the converter 5.

[0057] The converter 5 includes a primary winding 51 and a differential secondary winding 52. The differential secondary winding 52 includes two terminals, and the two terminals are respectively connected to the differential signal output by the power amplifier 4. The primary winding 51 also includes two terminals, one of which is grounded, and the other terminal of the primary winding 51 is connected to the low-noise power amplifier 64. The converter 5 performs primary conversion on the differential signal output by the power amplifier 4, and inputs the primary signal after primary conversion into the low-noise power amplifier 64.

[0058] In some embodiments, reference Figure 1 The power amplifier 4 and the converter 5 are connected by a bonding line 12 .

[0059] In some embodiments, reference Figure 1 The converter 5 and the low noise power amplifier 64 are connected by a bonding line 12 .

[0060] In some embodiments, the converter 5 is a balun converter 5, the primary winding 51 of the balun converter 5 is a single-ended winding, and the differential secondary signal of the balun converter 5 receives the differential signal of the power amplifier 4. The balun converter 5 performs single-ended conversion on the differential signal output by the power amplifier 4 and outputs it into a single-ended signal, and inputs the single-ended signal to the low-noise power amplifier 64.

[0061] After the low-noise power amplifier 64 receives the primary signal input by the converter 5, it amplifies the gain of the primary signal and outputs it to the receiving mixer 7 after gain amplification. After the receiving mixer 7 down-converts the amplified primary signal, it outputs it as a down-converted signal and inputs the down-converted signal into the receiving filter 8.

[0062] In some embodiments, the low noise power amplifier 64 is a current-mode low noise power amplifier 64 having a plurality of gain settings.

[0063] In some embodiments, the low noise power amplifier 64 has ten gain levels, the first four gain levels use a step-by-step current reduction method to achieve gain reduction, and the last six gain levels use a resistive attenuation network to reduce gain.

[0064] The receiving filter 8 performs low-pass filtering on the down-converted signal input by the receiving mixer 7, and further outputs it as a standard signal, which is input into the analog-to-digital converter 9. The analog-to-digital converter 9 converts the standard signal from an analog signal to a digital signal, and outputs a digital signal of the standard signal.

[0065] The output of the analog-to-digital converter 9 is the reference signal receiving power (RSRP). By comparing the reference signal receiving power with the transmission power of the target baseband signal, the difference between the transmission power and the reference signal receiving power is obtained, and the difference is the compensation power.

[0066] The gain compensation subcircuit 10 generates a digital compensation signal at the compensation power, and superimposes the digital compensation signal on the output of the analog-to-digital converter 9. Since the digital compensation signal and the output of the analog-to-digital converter 9 are both digital signals, a preset signal is obtained after superposition.

[0067] In some embodiments, the gain compensation sub-circuit 10 is integrated into the SOC of the radio frequency chip.

[0068] In some embodiments, before compensating the receiving gain of the RF chip, the transmitting power of the RF chip is calibrated in advance, and the gain of the RF chip is compensated using the calibrated RF power of the RF chip.

[0069] In some embodiments, reference Figure 1 and Figure 2The receiving gain compensation subcircuit 10 also includes a transmitter signal strength indicator 13 (TSSI) and a self-calibration source 14 (SCS). The transmitter signal strength indicator 13 also receives the differential signal output by the power amplifier 4; the self-calibration source 14 is used to generate a reference baseband signal with a constant power and input the reference baseband signal to the transmitter signal strength indicator 13. The transmitter signal strength indicator 13 performs segmented calibration on the target baseband signal according to the constant power of the reference baseband signal; the output value of the transmitter signal strength indicator 13 indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator 13.

[0070] In some embodiments, the transmitter signal strength indicator 13 is provided with an M-level piecewise linear attenuation network, a transmitter signal strength attenuation network (Transmitter Signal Strength Indication Attenuation, TSSI-Att), and an M-level piecewise linear attenuation network for segmented calibration of the transmission power of the target baseband signal.

[0071] In some embodiments, the transmitter signal strength indicator 13 is provided with a four-level piecewise linear attenuation network, with the attenuation degree increasing from zero, namely level 00, level 01, level 10 and level 11.

[0072] In some embodiments, the transmitter signal strength indicator 13 is provided with a three-level piecewise linear attenuation network, with the attenuation degree increasing from zero, namely level 00, level 01 and level 11.

[0073] In some embodiments, the receiving filter 8 also receives an output signal of a transmitter signal strength indicator 13, performs low-pass filtering on the output signal of the transmitter signal strength indicator 13, and inputs the low-pass filtered output signal into the analog-to-digital converter 9. The output value of the analog-to-digital converter 9 indicates the strength of the output signal of the transmitter signal strength indicator 13.

[0074] In some embodiments, reference Figure 1 The structure diagram and Figure 3 The flow chart shown in the figure uses the transmitter signal strength indicator 13 and the self-calibration source 14 to calibrate the transmission power, including the following steps:

[0075] S100, obtaining a constant power of a reference baseband signal output from a calibration source 14;

[0076] S200 , based on the constant power of the self-calibration source 14 and according to the M-level segmented linear attenuation network in the transmitter signal strength indicator 13 , calibrate the transmission power of the target baseband signal in M ​​segments.

[0077] In some embodiments, reference Figure 1 The structure diagram and Figure 4 The flowchart shown in the figure uses the transmitter signal strength indicator 13 with the attenuation network gears of gears 00, 01 and 11 to obtain the constant power of the reference baseband signal output by the self-calibration source 14, including the following steps:

[0078] S110, the transmitter signal strength indicator 13 is enabled, the attenuation network of the transmitter signal strength indicator 13 is adjusted to level 00, the power amplifier 4 is in a closed state, and the self-calibration source 14 is turned on; the self-calibration source 14 outputs a reference baseband signal at a constant power, the transmitter signal strength indicator 13 receives the reference baseband signal output by the self-calibration source 14, and the output signal of the transmitter signal strength indicator 13 passes through the receiving filter 8 and the analog-to-digital converter 9 in sequence, and the output value is D-SCS; D-SCS indicates the signal strength of the reference baseband signal output by the self-calibration source 14 at a constant power;

[0079] S120, turn off the self-calibration source 14, turn on the power amplifier 4, and keep the attenuation network of the transmitter signal strength indicator 13 at 00; the digital-to-analog converter 1, the transmission filter 2 and the transmission mixer 3 perform digital-to-analog conversion, low-pass filtering and up-conversion on the target baseband signal, and then input it to the power amplifier 4, the power amplifier 4 amplifies the signal and then inputs it into the transmitter signal strength indicator 13, the transmitter signal strength indicator 13 receives the output signal of the power amplifier 4, and the output signal of the transmitter signal strength indicator 13 passes through the receiving filter 8 and the analog-to-digital converter 9 in turn, and the output value is D-PA; D-PA indicates the strength of the signal input into the transmitter signal strength indicator 13 by the power amplifier 4;

[0080] S130, adjust the amplification factor of the power amplifier 4, thereby changing the signal strength of the signal input by the power amplifier 4 to the transmitter signal strength indicator 13, until D-PA is equal to D-SCS, at which time the strength of the output signal of the power amplifier 4 is equal to the signal strength of the reference baseband signal output by the self-calibration source 14 at a constant power, and then the constant power of the self-calibration source 14 is equal to the output power of the power amplifier 4 at this time.

[0081] In some embodiments, when the transmitter signal strength indicator 13 and the self-calibration source 14 are used to calibrate the transmission power, after the transmitter signal strength indicator 13 is enabled, a DC offset cancellation (DCOC) is performed on the transmitter signal strength indicator 13 .

[0082] In some embodiments, reference Figure 1 The structure diagram and Figure 5 The flow chart shown in the figure calibrates the transmission power based on the constant power of the self-calibration source 14 using the transmitter signal strength indicator 13 and the self-calibration source 14 with the attenuation network gears of gears 00, 01 and 11, including the following steps:

[0083] S210, the transmitter signal strength indicator 13 is enabled, and the attenuation network of the transmitter signal strength indicator 13 is adjusted to level 11, which is the maximum attenuation level of the attenuation network of the transmitter signal strength indicator 13. The power amplifier 4 is in a closed state, and the self-calibration source 14 is turned on; the self-calibration source 14 outputs a constant signal at a constant power, the transmitter signal strength indicator 13 receives the constant signal, and attenuates the constant signal. The output attenuated constant signal passes through the receiving filter 8 and the analog-to-digital converter 9 in sequence, and the output value is D-SCS-ATT-11; D-SCS-ATT-11 indicates the output signal strength of the transmitter signal strength indicator 135 under a constant signal and the attenuation network is level 11;

[0084] S220, turn off the self-calibration source 14, turn on the power amplifier 4, and keep the attenuation network of the transmitter signal strength indicator 13 at level 11; the target baseband signal passes through the digital-to-analog converter 1, the transmit filter 2 and the transmit mixer 3 in sequence and then inputs into the power amplifier 4, the power amplifier 4 amplifies the signal and then inputs into the transmitter signal strength indicator 13, after being attenuated by the attenuation network of the transmitter signal strength indicator 13, the output of the transmitter signal strength indicator 13 passes through the receiving filter 8 and the analog-to-digital converter 9 in sequence, and the output value is D-PA-ATT-11;

[0085] S230, adjusting the amplification factor of the power amplifier 4, thereby changing the signal strength of the output signal of the power amplifier 4, until D-PA-ATT-11 is equal to D-SCS-ATT-11, at which time the output power of the output signal strength of the power amplifier 4 is equal to the constant power of the self-calibration source 14; at this time, the output power of the power amplifier 4 is recorded as PRF-0;

[0086] S240, maintaining the transmitter signal strength indicator 13 attenuation network 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 13, 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 13 after passing through the receiving filter 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;

[0087] S250, maintaining the output power of the power amplifier 4 at PRF-1, adjusting the attenuation network of the transmitter signal strength indicator 13 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 level 01 of the transmitter signal strength indicator 13, 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 135 after passing through the receiving filter 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;

[0088] S260, maintain the output power of the power amplifier 44 at PRF-2, adjust the attenuation network of the transmitter signal strength indicator 13 to level 00, gradually reduce the output power of the power amplifier 44 at intervals of 0.5 dBm, and obtain PRF-3; the output value of the signal output by the transmitter signal strength indicator 135 after passing through the receiving filter 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.

[0089] In some embodiments, in step S210 , the self-calibration source 14 outputs a reference signal at a reference power, and there is a deviation between the reference power and the constant power, and the deviation is less than 1%.

[0090] In some embodiments, a transimpedance amplifier and a programmable gain amplifier are further included. The signal output by the transmitter signal strength indicator 13 passes through the transimpedance amplifier and the programmable gain amplifier in sequence and then is input into the analog-to-digital converter 9 .

[0091] In some embodiments, the linear equation diagram after the target baseband signal transmission power calibration is as follows: Figure 6 shown.

[0092] An embodiment of the present invention also provides a receiving gain compensation method for a radio frequency chip.

[0093] Reference Figure 7 As shown in the flowchart, the receiving gain compensation method includes the following steps:

[0094] P100, obtaining compensation power; the compensation power is the difference between the RF transmission power and the reference signal reception power output by the analog converter;

[0095] P200, obtaining a digital compensation signal; based on the compensation power, the gain compensation subcircuit 10 outputs a digital compensation signal at the compensation power;

[0096] P300, superimposing a digital compensation signal; superimposing the digital compensation signal on the digital signal output by the analog-to-digital converter 9 to obtain a preset signal.

[0097] In some embodiments, reference Figure 7 and Figure 8 The flow chart shown in the figure includes the following steps before obtaining the compensation power:

[0098] R100, obtain the transmit power; obtain the transmit power under the target baseband signal;

[0099] R200, obtain a reference signal receiving power; obtain a reference signal receiving power output by the analog-to-digital converter 9 under the target baseband signal.

[0100] The difference between the transmit power of the target baseband signal and the received power of the reference signal is the compensation power.

[0101] In some embodiments, before obtaining the transmit power under the target baseband signal, the transmit power of the radio frequency chip is calibrated in advance, and the compensation power is obtained using the calibrated transmit power.

[0102] 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. A receiving gain compensation circuit of a radio frequency chip, characterized in that: include: A digital-to-analog converter, a transmit filter, a transmit mixer, a power amplifier, a converter, a low noise power amplifier, a receive mixer, a receive filter, an analog-to-digital converter, and a gain compensation subcircuit; The input end of the digital-to-analog converter is connected to the target baseband signal, and the output end of the digital-to-analog converter is connected to the transmit filter, and the target baseband signal includes an in-phase signal and an orthogonal signal; the transmit filter performs low-pass filtering on the target baseband signal and outputs it as a filtered signal, and inputs the filtered signal into the transmit mixer; the transmit mixer performs up-conversion on the filtered signal and outputs it as an up-converted signal, and inputs the up-converted signal into the power amplifier; The power amplifier amplifies the up-converted signal, and outputs the amplified up-converted signal in a differential manner, and inputs the differential signal into the converter; the converter comprises a primary winding and a differential secondary winding, the primary winding is coupled to the input end of the low-noise power amplifier, and the differential secondary winding is coupled to the output end of the power amplifier; the converter is used to output the differential signal as a primary signal; The low noise power amplifier receives the primary signal, amplifies the primary signal and then inputs the amplified signal into the receiving mixer; The receiving mixer down-converts the amplified primary signal and outputs it as a down-converted signal, and inputs the down-converted signal into the receiving filter; The receiving filter filters the down-converted signal and outputs it as a standard signal, and inputs the standard signal into the analog-to-digital converter, and the analog-to-digital converter outputs a reference signal receiving power; The gain compensation subcircuit generates a digital compensation signal at a compensation power, and superimposes the digital compensation signal on the output of the analog-to-digital converter to obtain a preset signal; the compensation power is equal to the difference between the transmit power of the target baseband signal and the received power of the reference signal; The receive gain compensation circuit also includes a transmitter signal strength indicator and a self-calibration source; The power amplifier also inputs the differential 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, 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; 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.

2. The receiving gain compensation circuit of the radio frequency chip according to claim 1, characterized in that: The receiving filter receives the calibration baseband signal output by the transmitter signal strength indicator, performs low-pass filtering on the calibration baseband signal, and then inputs the signal into the analog-to-digital converter; The output value of the analog-to-digital converter indicates the strength of the calibration baseband signal after calibration by the transmitter signal strength indicator.

3. The receiving gain compensation circuit of the radio frequency chip according to claim 1, characterized in that: The converter is a balun converter, the primary winding of the balun converter is a single-ended winding, and the balun converter inputs a single-ended signal to the low-noise power amplifier.

4. The receiving gain compensation circuit of the radio frequency chip according to claim 3, characterized in that: The differential secondary winding of the balun transformer receives the differential signal output by the power amplifier.

5. The receiving gain compensation circuit of the radio frequency chip according to claim 1, characterized in that: The gain compensation subcircuit is integrated in the SOC of the radio frequency chip.

6. A receiving gain compensation method for a radio frequency chip, the method being applied to the receiving gain compensation circuit according to any one of claims 1 to 5, characterized in that: The following steps are involved: Obtaining compensation power; The gain compensation subcircuit obtains a digital compensation signal at the compensation power based on the compensation power; The digital compensation signal is superimposed on the digital signal output by the analog-to-digital converter to obtain a preset signal.

7. The receiving gain compensation method according to claim 6, characterized in that: Before obtaining the compensation power, the following steps are also included: Obtain the transmission power of the target baseband signal; Obtaining a reference signal received power output by the analog-to-digital converter; The compensation power is obtained based on the transmit power and the reference signal received power.

8. The receiving gain compensation method according to claim 7, characterized in that: Before obtaining the transmission power of the target baseband signal, the following steps are also included: Calibrate the transmit power of the RF chip.

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