Local oscillator leakage calibration method and device of radio frequency transceiver and radio frequency transceiver

Abstract

The invention provides a local oscillator leakage calibration method and device of a radio frequency transceiver and the radio frequency transceiver. The calibration method comprises the steps of determining a receiving path compensation code corresponding to at least one receiving gain gear when the receiving path is in a state without a radio frequency input signal; the receiving path compensation code is used for compensating local oscillation leakage of the receiving path; when the sending path and the receiving path are in an open state, the sending path and the receiving path are connected to form a self-loopback path, and sending path compensation codes corresponding to a plurality of sending gain gears in the sending path are determined according to a receiving path compensation code corresponding to a selected receiving gain gear; the transmission path compensation code is used for compensating local oscillation leakage of the transmission path. Dependence of an external instrument can be eliminated, the calibration process is simplified, the mass production cost is reduced, the local oscillator leakage compensation precision is improved, and stable performance of the radio frequency transceiver is guaranteed.

Description

Technical Field

[0001] This application belongs to the field of wireless communication technology and relates to a method, apparatus and radio frequency transceiver for local oscillator leakage calibration. Background Technology

[0002] In the field of wireless communication technology, radio frequency (RF) transceivers, as core components for converting between digital and RF signals, are widely used in various wireless communication devices such as Bluetooth, WiFi, and mobile terminals. During the modulation and demodulation of RF signals, local oscillator (LO) leakage is a critical issue affecting the communication performance of RF transceivers. This problem directly degrades the signal-to-noise ratio (SNR), leading to decreased demodulation performance at the receiver, increased bit error rate, and problems such as limited signal amplitude at the receiver and increased cyclic redundancy check (CRC) errors, severely impacting the stability and reliability of wireless communication.

[0003] Currently, there are many shortcomings in the local oscillator leakage calibration of RF transceivers: the mass production testing stage relies on external instruments and dedicated test boards, which increases testing costs and equipment testing time; the calibration process requires the use of signal processing modules that consume a lot of digital resources, resulting in an increase in chip area; the hardware design requires additional dedicated calibration circuits, which increases hardware complexity; it cannot adapt to the aging scenarios after long-term chip use and cannot effectively cope with the performance degradation caused by aging; after the whole machine leaves the factory, due to environmental and conditional limitations, it is extremely difficult to recalibrate by relying on external equipment.

[0004] Therefore, there is an urgent need for a local oscillator leakage calibration scheme for RF transceivers that does not rely on external instruments, consumes low resources, supports self-calibration, and has high calibration accuracy. Summary of the Invention

[0005] This application provides a method, apparatus, and radio frequency transceiver for local oscillator leakage calibration, which solves the problems of high cost, long time, and great difficulty in local oscillator leakage calibration of radio frequency transceivers.

[0006] In a first aspect, this application provides a method for calibrating local oscillator leakage in an RF transceiver. The RF transceiver includes a transmit path, a receive path, and a local oscillator module. The local oscillator module provides a local oscillator signal to the transmit path and the receive path. Local oscillator leakage exists in the transmit path and / or the receive path. The calibration method includes: when the receive path is in a state without an RF input signal, determining a receive path compensation code corresponding to at least one receive gain level; the receive path compensation code is used to compensate for the local oscillator leakage of the receive path; when the transmit path and the receive path are in an on state, the transmit path and the receive path are connected to form a self-looping path, and determining a plurality of transmit path compensation codes corresponding to transmit gain levels in the transmit path according to the receive path compensation code corresponding to the selected receive gain level; the transmit path compensation code is used to compensate for the local oscillator leakage of the transmit path.

[0007] In one implementation of the first aspect, determining the receive path compensation code corresponding to the receive gain level includes:

[0008] At a certain receive gain level, the codewords of the compensation code are adjusted and the received DC component corresponding to each codeword is obtained. The codeword corresponding to the received DC component that is less than a first threshold is selected as the receive path compensation code corresponding to that receive gain level.

[0009] In one implementation of the first aspect, selecting the codeword corresponding to the received DC component that is less than a first threshold as the receive path compensation code corresponding to the receive gain level includes: selecting the codeword corresponding to the smallest received DC component as the receive path compensation code corresponding to the receive gain level.

[0010] In one implementation of the first aspect, the receiving path compensation code includes an in-phase compensation code and a quadrature compensation code. Adjusting the codewords of the compensation code and obtaining the received DC component corresponding to each codeword, and selecting the codeword corresponding to the received DC component less than a first threshold as the receiving path compensation code for the receiving gain level, includes: fixing the codewords of the in-phase compensation code as initial values; scanning the codewords of the quadrature compensation code within a preset first range to determine a first quadrature compensation code that minimizes the received DC component; based on the first quadrature compensation code, scanning the codewords of the in-phase compensation code to determine a first in-phase compensation code that minimizes the received DC component; based on the first in-phase compensation code, scanning the codewords of the quadrature compensation code a second time within a preset second range to determine a second quadrature compensation code that minimizes the received DC component, wherein the coverage area of ​​the first range is larger than the coverage area of ​​the second range; and selecting the second quadrature compensation code and the first in-phase compensation code as the receiving path compensation code for the receiving gain level.

[0011] In one implementation of the first aspect, determining the transmission path compensation code corresponding to multiple transmission gain levels in the transmission path includes: compensating for the local oscillator leakage of the reception path according to the selected reception gain level and the corresponding reception compensation code; adjusting the codeword of the compensation code and obtaining the transmission DC component corresponding to each codeword under a transmission gain level, and selecting the codeword corresponding to the transmission DC component that is less than a second threshold as the transmission path compensation code corresponding to the transmission gain level.

[0012] In one implementation of the first aspect, obtaining the transmit DC component corresponding to each codeword includes: filtering the original received signal using a notch filter to obtain a filtered signal; and subtracting the original received signal from the filtered signal to obtain the transmit DC component corresponding to each codeword.

[0013] In one implementation of the first aspect, the calibration method further includes: determining the selected receive gain level based on the line attenuation of the self-loop path.

[0014] In one implementation of the first aspect, the method further includes: performing in-phase quadrature compensation on the digital baseband signals in the transmitting path and the receiving path.

[0015] Secondly, this application provides a local oscillator leakage calibration device for an RF transceiver. The device includes a transmitting path, a receiving path, and a local oscillator module. The local oscillator module provides a local oscillator signal for the transmitting path and the receiving path. The transmitting path and the receiving path are connected to form a self-looping path. The transmitting path includes: a signal generation module for generating a digital baseband signal; a transmitting compensation module for compensating the transmitted DC component of the transmitting path; and a transmitting module for processing the digital baseband signal and related signals of the transmitted digital baseband signal. The receiving path includes: a receiving module for receiving and processing the related signals of the digital baseband signal; a receiving compensation module for compensating the received DC component of the receiving path; and a detection module for detecting the transmitted DC component and the received DC component.

[0016] Thirdly, this application provides a radio frequency transceiver, the radio frequency transceiver comprising: a signal generation module for generating a digital baseband signal; a transmission path including a transmission compensation module, the transmission compensation module using the transmission path compensation code obtained in any one of the first aspects to compensate for the local oscillator leakage of the transmission path; a reception path including a reception compensation module, the reception compensation module using the reception path compensation code obtained in any one of the first aspects to compensate for the local oscillator leakage of the reception path; and a local oscillator module for providing a local oscillator signal for the transmission path and the reception path.

[0017] As described above, the local oscillator leakage calibration method, apparatus, and RF transceiver of this application have the following beneficial effects:

[0018] 1. This application adopts a step-by-step strategy of first pre-calibrating the receiving path and then performing self-loop closed-loop calibration of the transmitting path to eliminate the interference of local oscillator leakage in the receiving path on the calibration of the transmitting path in advance, thereby improving the compensation accuracy. Relying on the self-loop architecture with direct connection between the receiving and transmitting paths, it eliminates the dependence on external test instruments, simplifies the calibration process, and reduces mass production costs. At the same time, it configures compensation codes separately for each gain level of the receiving and transmitting paths to achieve local oscillator leakage suppression at multiple gain levels, ensuring the performance stability of the RF transceiver under different working scenarios.

[0019] 2. This application eliminates dependence on external equipment, significantly reducing mass production and testing costs: Through the self-loop architecture formed by external coupling of the transmitting and receiving paths, it can achieve self-transmission and self-reception of the transmitting signal and accurate compensation of local oscillator leakage in both the receiving and transmitting paths without the need for external equipment such as ATE machines to provide a signal source. This completely solves the problem of dependence on external measuring instruments or dedicated measuring circuits in traditional calibration. At the same time, the local oscillator leakage of the transmitting path can be compensated and calibrated by a digital notch filter without the need to reconstruct complex circuits, which greatly simplifies hardware design and reduces hardware costs and environmental adaptation costs in the chip R&D and mass production stages.

[0020] 3. This application optimizes the calibration process and efficiency: By adopting the logic of "calibrating the receiver first and then calibrating the transmitter," the interference of the local oscillator leakage of the receiver path on the calibration of the transmitter path can be eliminated in advance, thus improving the calibration accuracy. At the same time, the DC component detection module supports two modes: averaging method and notch filter. The averaging method can improve the stability of DC detection in scenarios where there is no input at the receiver, while the notch filter can accurately filter out interference signals to extract the transmitted DC component, ensuring the reliability of detection at different calibration stages. After superimposing fast algorithms such as three-way search, the optimal solution can be located without traversing all compensation codes, which greatly simplifies the calibration logic and significantly shortens the calibration time, making it fully adaptable to the needs of time-sensitive scenarios such as power-on checks and self-calibration.

[0021] 4. This application supports dynamic self-calibration, ensuring long-term stable performance of the chip: The calibration scheme of this application supports self-test and self-calibration functions after the chip is powered on. Even if the chip experiences aging drift during long-term service, dynamic compensation can still be completed by re-executing the calibration process, continuously ensuring the local oscillator leakage suppression effect and RF performance indicators, effectively resisting the performance degradation caused by chip aging, and extending the product service life and reliability.

[0022] 5. Simplify calibration operation logic and improve mass production testing efficiency: The entire calibration process relies on a self-loop architecture and integrated digital circuits to achieve fully automatic execution, without the need for manual intervention to adjust external instruments or the test environment, which greatly simplifies the calibration operation process; combined with the time reduction brought by fast algorithms, it can significantly improve the test throughput in the chip mass production stage and further reduce the mass production testing cost. Attached Figure Description

[0023] Figure 1 The diagram shown is a flowchart of the calibration method described in the embodiments of this application.

[0024] Figure 2 The diagram shown is a specific flowchart of the calibration method described in an embodiment of this application.

[0025] Figure 3 The diagram shown is a structural schematic of the calibration device described in an embodiment of this application.

[0026] Figure 4 The diagram shown is a specific structural schematic of the calibration device described in an embodiment of this application.

[0027] Figure 5 The diagram shown is a structural schematic of the DC detection module described in an embodiment of this application.

[0028] Figure 6 The diagram shown is a structural schematic of the radio frequency transceiver described in an embodiment of this application. Detailed Implementation

[0029] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, unless otherwise specified, the following embodiments and features in the embodiments can be combined with each other.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] It should be noted that the complex intermediate frequency (IF) scheme (also known as zero IF or direct conversion architecture) is one of the mainstream signal processing architectures for RF transceivers. Its core is to achieve RF signal processing through the coordinated modulation and demodulation of in-phase (I-path) and quadrature (Q-path) signals. This scheme eliminates the need for complex IF filter circuits and multiple frequency conversion processes, simplifying the modulation logic and reducing the suppression requirements of the filters. It effectively simplifies hardware design, reduces device size, and lowers power consumption, thus becoming one of the mainstream design architectures for RF transceivers. The following section will describe the calibration method and apparatus for local oscillator leakage in the RF transceiver based on this architecture.

[0032] It should be understood that in practical applications, due to semiconductor process deviations, device mismatches, and device aging, RF transceivers with complex intermediate frequency architectures generally suffer from local oscillator leakage. In the transmission path, the baseband signal entering the IQ mixer carries a transmitted DC component. After this component is multiplied by the local oscillator signal, the RF output will generate three main types of signals: the target RF signal, the local oscillator leakage signal, and the image signal. Other signals are mostly intermodulation products, which will attenuate synchronously after the local oscillator and image signal are calibrated. Among them, the local oscillator leakage signal is located within the communication band and will directly degrade the signal-to-noise ratio, leading to a decrease in demodulation performance at the receiver, an increase in the bit error rate, and a serious impact on communication reliability. In the reception path, after the mixed signal is processed by modules such as mixers, process errors will also introduce a received DC component. This component, after being transmitted to the digital circuit via an analog-to-digital converter, will limit the signal amplitude at the receiver and degrade reception performance.

[0033] The calibration method and apparatus provided in this application are applied to RF transceivers. By accurately compensating for the DC components in the transmitting and receiving paths, they calibrate errors caused by local oscillator leakage, significantly reducing non-ideal DC interference before mixing. This application, through a self-loop architecture and a digital detection circuit including a DC component detection module and a compensation module, eliminates reliance on external testing instruments (such as automatic testing equipment, spectrum analyzers, etc.), achieving fully automated local oscillator leakage detection and compensation at the chip level. This not only effectively reduces mass production testing time and hardware costs but also supports power-on self-testing and aging drift dynamic compensation after system deployment, thereby extending product service life and ensuring long-term stable and reliable communication performance.

[0034] The technical solutions in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0035] like Figure 1As shown, this embodiment provides a method for calibrating local oscillator leakage in an RF transceiver. The RF transceiver includes a transmit path, a receive path, and a local oscillator module. The local oscillator module provides a reference frequency (i.e., a local oscillator signal) for signal transmission in the transmit path and signal reception in the receive path. Local oscillator leakage exists in the transmit path and / or the receive path. The calibration method includes:

[0036] S1: When the receiving path is in a state of no RF input signal, determine the receiving path compensation code corresponding to at least one receiving gain level; the receiving path compensation code is used to compensate for the local oscillator leakage of the receiving path.

[0037] S2: When the transmitting and receiving paths are in the open state, the transmitting and receiving paths are connected to form a self-looping path. The transmitting path compensation code corresponding to multiple transmitting gain levels in the transmitting path is determined according to the receiving path compensation code corresponding to the selected receiving gain level. This transmitting path compensation code is used to compensate for the local oscillator leakage of the transmitting path.

[0038] It should be understood that the aforementioned gain levels refer to the gain levels of signal amplification modules (such as the power amplifier in the transmitting path and the low-noise amplifier in the receiving path) in the transmitting and receiving paths of the RF transceiver. Each gain level corresponds to a fixed amplification factor (i.e., gain value), which can be switched according to the actual communication scenario (such as signal strength and transmission distance). Since the operating states (such as current and voltage) of the devices in the path differ under different gain levels, the degree of local oscillator leakage will also be different. Therefore, a corresponding compensation code can be configured separately for each gain level based on the corresponding DC component to ensure the calibration effect across the entire gain range.

[0039] It should also be noted that the aforementioned receive path compensation code is determined based on the DC component of the receive path, and the receive path compensation code corresponds to the receive gain level; similarly, the aforementioned transmit path compensation code is determined based on the DC component of the transmit path, and the transmit path compensation code corresponds to the transmit gain level. The receive path compensation code is determined based on the DC component corresponding to the local oscillator leakage of the receive path when the receive path is in a state without RF input signal, and each receive gain level also corresponds to a unique receive path compensation code. Similarly, the transmit path compensation code is determined based on the DC component of the transmit path detected by the receiver under the self-loop path (i.e., the DC component after the transmit path local oscillator leakage is transmitted through the self-loop path), and each transmit gain level also corresponds to a unique transmit path compensation code.

[0040] For example, the received DC component corresponding to each codeword can be obtained in the following way: when the receiving channel is in a state without radio frequency input signal, multiple sets of DC component related parameters are continuously collected by the received DC component detection module, and the average value of the collected parameters is calculated by averaging method to eliminate the interference of random noise. The final average value is the received DC component corresponding to the local oscillator leakage of the receiving channel itself.

[0041] For example, the specific process of determining the transmission path compensation code corresponding to multiple transmission gain levels in the transmission path based on the transmission path compensation code corresponding to the selected reception gain level can be as follows: After the transmission path and the reception path are connected to form a self-loop path, firstly, an appropriate reception gain level is selected, and the reception path compensation code obtained by pre-calibration of that level is retrieved; secondly, the reception path compensation code is loaded into the compensation module of the reception path to compensate for the local oscillator leakage of the reception path itself; on this basis, for each transmission gain level of the transmission path, the corresponding level is turned on in sequence and the transmission DC component detected by the receiver is collected (i.e., the residual DC signal after the local oscillator leakage of the transmission path is transmitted through the self-loop link); finally, based on the collected transmission DC component, the transmission path compensation code corresponding to each transmission gain level is calculated and determined, and the compensation code is loaded into the transmission path compensation module to complete the accurate compensation for the local oscillator leakage of the transmission path.

[0042] In some specific embodiments, determining the receive path compensation code corresponding to the receive gain level includes: adjusting the codeword of the compensation code and obtaining the received DC component corresponding to each codeword under a receive gain level, and selecting the codeword corresponding to the received DC component that is less than a first threshold as the receive path compensation code corresponding to the receive gain level.

[0043] Optionally, when adjusting the codewords of the compensation code and obtaining the received DC component corresponding to each codeword, the codeword corresponding to the smallest received DC component can be selected as the receiving path compensation code corresponding to the receiving gain level.

[0044] For example, the received DC component (i.e., the DC component corresponding to the local oscillator leakage of the receiving path) includes the in-phase DC component (I path) and the quadrature DC component (Q path), which need to be calibrated separately using corresponding compensation codes. To improve calibration efficiency and accuracy, an iterative scanning strategy of "fixing one path and scanning the other" can be adopted. Taking the codeword corresponding to the smallest received DC component as the receiving path compensation code corresponding to that receiving gain level as an example, the specific operation is as follows:

[0045] First, an initial scan of the wide-range locking quadrature compensation code is performed. Specifically, the codeword (dc_i_code) of the fixed in-phase compensation code is set to an initial value (e.g., 0). Within a preset first range, the codeword (dc_q_code) of the quadrature compensation code is scanned across the entire range. The DC component of the receiving path corresponding to different dc_q_codes is calculated, and the first quadrature compensation code that minimizes the received DC component is selected. For example, the first range can cover all possible compensation values ​​to ensure that no optimal solution is missed.

[0046] Second, a scan is performed based on the first quadrature compensation code to calibrate the in-phase compensation code. Specifically, based on the aforementioned first quadrature compensation code, a full-range scan of the codeword (dc_i_code) of the in-phase compensation code is performed, the DC component of the receiving path corresponding to different dc_i_codes is calculated, and the first in-phase compensation code that minimizes the received DC component is determined.

[0047] Third, the quadrature compensation code is iteratively optimized within a small range. Specifically, based on the first in-phase compensation code mentioned above, the codeword (dc_q_code) of the quadrature DC component compensation code is scanned iteratively twice within a preset second range.

[0048] It should be noted that the coverage area of ​​the second range is smaller than that of the first range (for example, taking the first orthogonal compensation code obtained in the first step as the center, the codeword range of ±6 is taken as the second range). By fine-tuning the small range, the calibration error caused by environmental fluctuations and device boundary characteristics is further eliminated, and finally the second orthogonal compensation code that minimizes the received DC component is determined.

[0049] Fourth, select the second quadrature compensation code and the first in-phase compensation code as the receiving path compensation codes corresponding to the receiving gain level.

[0050] It should be noted that the above steps use a traversal method, but the scanning method for compensation codes in this application is not limited to this. For example, a three-way search method can also be used to determine the optimal in-phase compensation code and quadrature compensation code: by successively dividing the scanning range into three parts and comparing the residual DC components at the endpoints of the intervals, the sub-interval containing the compensation code with the smallest residual can be quickly locked, and calibration can be completed without traversing all codewords, effectively improving scanning efficiency.

[0051] The scanning strategy for the compensation code in this application can be flexibly adjusted according to the actual scenario. For example, binary search, parabolic interpolation, and golden section search methods can also be used. As long as the selection of the compensation code that minimizes the received DC component can be achieved, it falls within the protection scope of this application.

[0052] In this embodiment, the above-mentioned iterative scanning strategy can effectively solve the problem of indistinct peak values ​​of boundary chips. For example, when the initial value of dc_i_code is 0 and it actually needs to be compensated to 50, the first wide-range scan is prone to the situation of indistinct drop near the optimal value and misselection of adjacent non-optimal codes. However, the small-range second iteration can accurately lock the optimal solution, further ensuring the stability and accuracy of calibration.

[0053] In some specific embodiments, determining the transmission path compensation code corresponding to the transmission gain level includes: compensating for the local oscillator leakage of the receiving path according to the selected receiving gain level and the corresponding receiving compensation code; under a transmission gain level, adjusting the codeword of the compensation code and obtaining the transmission DC component corresponding to each codeword, and selecting the codeword corresponding to the transmission DC component that is less than a second threshold as the transmission path compensation code corresponding to the transmission gain level.

[0054] Optionally, when adjusting the codewords of the compensation code and obtaining the corresponding DC components of each codeword, the codeword corresponding to the smallest DC component can be selected as the compensation code for the transmission path corresponding to the transmission gain level.

[0055] It should be noted that the transmitted DC component (i.e., the DC component corresponding to the local oscillator leakage of the transmission path) also includes the in-phase DC component (I path) and the quadrature DC component (Q path). Both need to be calibrated separately using the corresponding compensation codes. For specific calibration methods, please refer to the relevant description of the received DC component above, which will not be elaborated on here.

[0056] For example, the above-mentioned acquisition of the transmitted DC component corresponding to each codeword can be achieved by: filtering the original received signal using a notch filter to obtain a filtered signal; and subtracting the filtered signal from the original received signal to obtain the transmitted DC component corresponding to each codeword. The transmitted DC component is caused by local oscillator leakage in the transmission path.

[0057] For example, before determining the transmit path compensation code, the selected receive gain level and the corresponding receive compensation code can be determined based on the line attenuation of the self-loop path.

[0058] Specifically, the self-loop path is a direct link between the transmitting and receiving paths. Since the RF signal power output from the transmitting path is typically high, directly inputting it into the receiving path can easily lead to saturation of the receiving devices, affecting calibration accuracy. To address this, the hardware can use a dedicated switch to control a low-noise amplifier connected to a load to ground, effectively attenuating the high-power signal in the direct link. The specific attenuation value can be determined through actual measurement. For example, based on calibration requirements, the optimal operating point of the target input signal power of the analog-to-digital converter in the receiving path can be determined (e.g., -10dBm). Based on this, a suitable receiving gain value can be derived to ensure that the input signal power of the analog-to-digital converter in the receiving path is within its optimal linear operating range, avoiding calibration errors caused by excessively strong signal saturation or insufficient signal-to-noise ratio due to excessively weak signals.

[0059] For example, the required receive gain value can be calculated by subtracting the RF signal power output from the transmit path from the target input signal power of the analog-to-digital converter, and adding the attenuation value caused by the grounding of the low-noise amplifier. Then, based on the calculated receive gain value, the corresponding receive gain level is matched, and the receive path compensation code obtained by pre-calibration under that level is retrieved, providing a basis for the accurate calibration of the transmit path compensation code in the future.

[0060] Optionally, after determining the receive path compensation code corresponding to at least one receive gain level, the calibration method further includes: determining whether the received DC component corresponding to each receive gain level is less than a third threshold. If the received DC component corresponding to each receive gain level is less than the third threshold, it is determined that the local oscillator leakage compensation effect of the receive path meets expectations, and the subsequent calibration process for the transmit path compensation code can proceed.

[0061] Optionally, after determining the transmission path compensation codes corresponding to multiple transmission gain levels in the transmission path, the calibration method further includes: determining whether the transmission DC component corresponding to each transmission gain level is less than a fourth threshold. If the transmission DC component corresponding to each transmission gain level is less than the fourth threshold, it is determined that the local oscillator leakage compensation effect of the transmission path meets the calibration requirements, and the local oscillator leakage closed-loop calibration process of the RF transceiver can be completed normally.

[0062] In some specific embodiments, the above calibration method further includes: performing in-phase quadrature compensation on the digital baseband signals in the transmitting and receiving paths.

[0063] It should be understood that due to the non-ideal hardware characteristics of RF transceivers (such as mixer phase imbalance, inconsistent filter amplitude-frequency response, and baseband circuit impedance mismatch), amplitude deviation and phase quadrature errors will occur between the in-phase branch (I-path) and quadrature branch (Q-path) signals of the digital baseband. This can also induce image signal interference. Specifically, during spectrum shifting, parasitic image components generated by the I / Q branch imbalance will be superimposed on the effective signal frequency band, further degrading calibration accuracy after coupling with the local oscillator leakage signal. Therefore, after DC component compensation, a digital domain in-phase quadrature calibration mechanism can be introduced to eliminate amplitude-phase imbalance and image signal interference.

[0064] For example, for the receiving path, when it is in a state without radio frequency input signal, the I / Q baseband signal after receiving DC component compensation is acquired. The amplitude and phase characteristics of the image signal are extracted by spectrum analysis, and the amplitude equalization coefficient and phase calibration coefficient of the I / Q branch are calculated to generate the corresponding receiving I / Q compensation parameters. During actual signal reception, these parameters are used to correct the digital baseband I / Q signal in real time, to offset the amplitude and phase deviation caused by branch imbalance, and to suppress the interference of the image signal on the effective signal.

[0065] For example, for the transmission path, when the transmission path and the receiving path are connected to form a self-looping path, the transmission feedback I / Q baseband signal after receiving DC component compensation and transmission DC component compensation is collected. The image leakage component caused by I / Q imbalance in the transmission path is detected, and the transmission I / Q compensation parameters are optimized and calculated based on the image signal suppression requirements. During actual signal transmission, the digital baseband I / Q signal is pre-corrected using these parameters to ensure that the RF signal output by the transmission path meets the strict amplitude-phase orthogonality requirements, thereby reducing the energy of the image signal from the source.

[0066] Through the above-mentioned in-phase quadrature compensation in the digital domain, the suppression of residual local oscillator leakage components and the elimination of image signals can be achieved simultaneously, further improving the signal quality and calibration stability of the entire RF transceiver link.

[0067] Figure 2 This paper illustrates a possible specific workflow of the calibration method of this application. Through a phased execution logic of "receive path pre-calibration, transmit path closed-loop calibration, and IQ imbalance compensation", it achieves accurate compensation for local oscillator leakage in the transmit and receive paths of the RF transceiver. Specifically, it includes the following steps:

[0068] Step 1: DC component pre-calibration of the receiver path (Rx). This specifically includes:

[0069] S101: After the program starts, it sequentially executes physical layer (PHY) initialization and radio frequency (RF) module initialization to complete the hardware configuration before calibration.

[0070] S102: Controls the RF transceiver to enter independent receiving mode (Rx Only mode), that is, the receiving path is in a state without RF input signal.

[0071] S103: Configure the DC component detection module of the receiving path to the averaging method mode to reduce the interference of random noise on the DC component detection.

[0072] S104: Read the first level of receiver gain code (Rx GainCode) from the receiver gain table (Rx gain table).

[0073] S105: Performs a forced activation operation on the read receive gain code to ensure that the analog circuit configuration for that gain level is effective.

[0074] S106: Perform in-phase DC component calibration (Rx DC I-channel calibration) of the receiving path to determine the in-phase DC compensation code at the current gain level.

[0075] S107: Perform orthogonal DC component calibration (Rx DC Q-path calibration) of the receiving path to determine the orthogonal DC compensation code at the current gain level.

[0076] S108: Read the next receiver gain code from the receiver gain table.

[0077] S109: Determine if the next receiver gain code is empty: If it is not empty, return to step S105 and repeat; if it is empty, execute step S110.

[0078] S110: Controls the RF transceiver to disable independent receive mode.

[0079] S111: Perform threshold judgment on the calibration effect of all receiving gain levels: determine whether the received DC residual corresponding to each receiving gain level is less than the preset third threshold (e.g., 5 coding units); if all levels meet the threshold, proceed to step two; otherwise, determine that the calibration has failed and end the process.

[0080] Step 2: Closed-loop calibration of the DC component of the transmit path (Tx). This specifically includes:

[0081] S201: Controls the RF transceiver to enter independent transmission mode (Tx Only mode).

[0082] S202: Configure the DC component detection module of the receiving path to notch filter mode, so as to accurately extract the DC component of the transmitting path by filtering out interference signals in the signal.

[0083] S203: Open the receiving path, so that the output of the transmitting path is directly connected to the input of the receiving path, forming a self-loopback path.

[0084] S204: Select an appropriate receiving gain level based on the line attenuation parameters of the self-loop path; at the same time, load the receiving path compensation code corresponding to this level to eliminate the interference of the receiving path local oscillator leakage on the transmitting path calibration.

[0085] S205: Read the first transmission gain code (Tx GainCode) from the transmission gain table (Tx gain table).

[0086] S206: Perform a force operation on the read transmit gain code to ensure that the analog circuit configuration for that gain level is effective.

[0087] S207: Perform in-phase DC component calibration of the transmission path (Tx DC I-path calibration) to determine the in-phase DC compensation code under the current gain level.

[0088] S208: Perform orthogonal DC component calibration of the transmission path (Tx DC Q-path calibration) to determine the orthogonal DC compensation code at the current gain level.

[0089] S209: Read the next transmission gain code from the transmission gain table.

[0090] S210: Determine if the next transmission gain code is empty: If it is not empty, return to step S206 and repeat the execution; if it is empty, execute step S211.

[0091] S211: Perform threshold judgment on the calibration effect of all transmission gain levels: determine whether the DC residual corresponding to each transmission gain level is less than the preset fourth threshold (e.g., 10 coding units); if all levels meet the threshold, proceed to step three; otherwise, determine that the calibration has failed and end the process.

[0092] Step 3: IQ Imbalance (IQM) Compensation and Calibration Completion. This includes:

[0093] S301: Perform IQ imbalance calibration of the transmitting and receiving paths to eliminate mirror signal interference caused by amplitude and phase deviation of the I / Q branches.

[0094] S302: Threshold judgment on the IQ imbalance calibration effect: Determine whether the power ratio of the target signal and the IQM interference signal is greater than the preset fifth threshold (e.g., 35dB); if it is satisfied, proceed to step S303; otherwise, determine that the calibration has failed and end the process.

[0095] S303: Store calibration parameters such as the receive path compensation code, transmit path compensation code, and IQ imbalance compensation coefficient into a non-volatile storage medium (such as Flash or Efuse).

[0096] S304: Calibration process complete.

[0097] This embodiment achieves local oscillator leakage compensation across all gain levels of the RF transceiver through the above process, while ensuring calibration accuracy through multi-layer threshold decision-making, effectively improving the signal transmission stability of the RF transceiver.

[0098] like Figure 3 As shown, this application also provides a calibration device, including a transmitting path, a receiving path, and a local oscillator module. The local oscillator module provides a stable frequency reference signal (i.e., a local oscillator signal) for the transmitting and receiving paths. The transmitting and receiving paths are connected to form a self-looping path. The transmitting path includes: a generation module (such as a single-tone signal transmitting module) for generating a digital baseband signal; a transmission compensation module for compensating the transmitted DC component of the transmitting path; and a transmitting module for processing the digital baseband signal and its related signals. The receiving path includes: a receiving module for receiving and processing the related signals of the digital baseband signal; a receiving compensation module for compensating the received DC component of the receiving path; and a detection module for detecting the transmitted and received DC components.

[0099] For example, the above-mentioned transmitting module includes, but is not limited to: a transmitting signal scaling module, a digital-to-analog converter, a transmitting filter, a voltage-to-current converter, a transmitting mixer, and a power amplifier. The above-mentioned receiving module includes, but is not limited to: a low-noise amplifier, a receiving mixer, a transimpedance amplifier, a baseband IQ module, an analog-to-digital converter, and a receiving signal scaling module.

[0100] For example, the above-mentioned transmission path and receiving path are connected to form a self-looping path: the transmission pin of the transmission path and the receiving pin of the receiving path are combined with an external impedance matching network to form a self-looping path, thus enabling the self-transmission and self-reception of the transmission signal and the receiving signal.

[0101] Optionally, the above calibration device may further include a transmit IQ mismatch compensation module and a receive IQ mismatch compensation module, used to perform in-phase quadrature compensation on the digital baseband signals in the transmit and receive paths.

[0102] It should be understood that this device can achieve local oscillator leakage calibration without external instruments through a self-looping path. Specifically, the RF signal output from the transmitting path does not need to be transmitted through an external antenna. It is directly coupled to the receiving pin of the receiving path through an external impedance matching network, so that the transmitted signal can be directly captured by the receiving path, thereby completing the closed-loop calibration of local oscillator leakage.

[0103] For example, Figure 4 A specific architecture of a calibration device for local oscillator leakage of an RF transceiver according to this application is shown. The device includes a transmit path, a receive path, and a local oscillator module.

[0104] The transmission path, along the signal flow direction, includes, in sequence: a single-tone signal transmission module, a signal scaling module (TxScale), a transmit IQ mismatch compensation module (Tx IQM Comp), a transmit direct current compensation module (Tx DC Comp) (i.e., the transmit compensation module), a digital-to-analog converter (DAC), a transmit filter, a voltage-to-current converter (V2I), a transmit mixer (Tx Mixer), and a power amplifier (PA).

[0105] It should be noted that the aforementioned single-tone signal transmission module is used to generate a fixed-frequency and fixed-amplitude digital baseband signal; the transmission signal scaling module is used to scale the amplitude of the transmitted single-tone signal to match the input range of subsequent modules, avoiding signal amplitude overload; and the transmission IQ mismatch compensation module is used to correct the I / Q of the transmission path. The amplitude / phase / DC difference between the two signals ensures orthogonal matching between them, reducing the superposition of local oscillator leakage caused by mismatch; the transmit DC component compensation module compensates for the DC components of the I / Q channels of the transmit path, that is, it compensates for the local oscillator leakage of the transmit path; the digital-to-analog converter converts the digital signal into an analog signal; the transmit filter filters out quantization noise and high-frequency clutter in the output signal of the digital-to-analog converter, purifying the baseband analog signal; the voltage-to-current module converts the filtered voltage-type baseband signal into a current-type signal, adapting it to the current input characteristics of the transmit mixer; the transmit mixer receives the local oscillator signal provided by the local oscillator module, multiplies the baseband current signal with the local oscillator signal, and boosts the signal frequency to the radio frequency band; the power amplifier amplifies the radio frequency signal output by the transmit mixer to the power level that meets the transmission requirements.

[0106] The receiving path, along the signal flow direction, includes, in sequence: a low-noise amplifier (LNA), a receiving mixer (such as a transconductance mixer (GM-Mixer)), a transimpedance amplifier (TIA), a baseband IQ module (BIQ), an analog-to-digital converter (ADC), a receive direct current compensation module (Rx DC Comp) (i.e., the receive compensation module), a receive IQ mismatch compensation module (Rx IQM Com), a receive signal scaling module (Rx Scale), and a receive direct current check module (Rx DC Check).

[0107] It should be noted that the aforementioned low-noise amplifier is used to amplify the RF signal input to the self-loop path while minimizing its own noise to ensure the signal-to-noise ratio of the received signal; the receiving mixer is used to receive the local oscillator signal provided by the local oscillator module, multiply the amplified RF signal with the local oscillator signal, and reduce the signal frequency to the baseband band to achieve down-conversion; the transimpedance amplifier is used to convert the current-type baseband signal output from the receiving mixer into a voltage signal and amplify it to an amplitude suitable for subsequent modules; the baseband IQ module is used to filter and adjust the gain of the down-converted baseband signal, and separate the I and Q signals to prepare for analog-to-digital conversion; the analog-to-digital converter is used to convert the conditioned baseband analog signal into a digital signal; the receiving DC component compensation module is used to compensate for the DC component introduced by modules such as the mixer in the receiving path, that is, to compensate for the local oscillator leakage in the receiving path; the receiving signal scaling module is used to scale the corrected received signal amplitude to an input range suitable for subsequent modules; and the DC component detection module is used to detect the transmitted DC component corresponding to the local oscillator leakage in the transmitting path and the received DC component corresponding to the local oscillator leakage in the receiving path.

[0108] It should also be noted that, Figure 4 The output of the transmitting path (i.e., the signal output port of the PA) and the input of the receiving path (i.e., the signal input port of the LNA) form a self-looping path through the RF pin and an external impedance matching network. In normal communication scenarios, the signal is amplified by the PA and transmitted outward through the antenna; in local oscillator leakage calibration scenarios, the signal can be directly coupled to the receiving path through the self-looping path.

[0109] For example, an RF pin can simultaneously serve as both a transmit pin in a transmit path and a receive pin in a receive path, with path matching achieved through external impedance and load impedance. For instance, Figure 4 As shown, the external impedance Z0 serves as a matching circuit for the chip port. Setting Z0 = 50Ω makes the chip output an approximately 50-ohm characteristic impedance; the load impedance Z... L Set the impedance value to the same as the external impedance Z0 (e.g., 50Ω) to simulate the impedance characteristics of the antenna or external instrument, achieving precise matching between the external impedance and the load impedance, maximizing impedance matching efficiency and minimizing signal reflection. The transmitted signal is coupled to the receiving path through this impedance matching link, thus completing the signal link for closed-loop calibration.

[0110] It should be noted that the above architecture also includes a local oscillator module (such as a phase-locked loop-local oscillator module (PLL-LO)), which is used to provide a stable local oscillator signal for the transmitting mixer and the receiving mixer, serving as the frequency reference for signal up-conversion and down-conversion.

[0111] For example, the above architecture also includes a Universal Asynchronous Receiver Transmitter (UART), which is integrated into the Device Under Test (DUT) to enable serial communication between the calibration device and external devices, and to support the transmission and interaction of calibration parameters and status information.

[0112] In this embodiment, the RF transceiver local oscillator leakage calibration device adopts a self-loop circuit architecture. By simultaneously activating the transmit and receive paths under external impedance matching conditions, an external loop circuit is formed. This device does not rely on any external instruments or integrates complex computational circuits such as Discrete Fourier Transform / Fast Fourier Transform or envelope detection circuits. Calibration of the received and transmitted DC components can be completed through the DC component detection module in the receive path. Therefore, this device can achieve self-transmitting and self-receiving testing and calibration functions without increasing additional testing costs, significantly reducing hardware resource consumption and chip area costs, and effectively improving mass production testing efficiency and product reliability.

[0113] Next, we will take the detection of the transmitted DC component by the DC component detection module as an example, combined with... Figure 5 The DC component detection module in this application will be further described.

[0114] Figure 5In this circuit, the DC component detection module (Rx DC Check) receives the raw signal (denoted as "Rx DC IN") from the analog-to-digital converter (ADC) of the receiving path. It contains two core units: a notch filter and a subtractor. The notch filter unit filters the raw input signal, attenuating the signal energy of a specified frequency to below a preset threshold. The subtractor unit receives two input signals: the raw signal (Rx DC IN) and the notch filter output signal. By performing a difference operation between the raw signal and the notch filter output signal, the DC component output (denoted as "Rx DC OUT") is finally obtained.

[0115] It should be noted that during the DC component calibration phase of the transmitting path, the self-looping path is in the ON state. At this time, the local oscillator (LO) signals of the transmitting and receiving paths are from the same source, causing local oscillator leakage in the transmitting and receiving paths, as well as the transmitted single-tone signal and the image signal, to be simultaneously superimposed on the ADC input of the receiving path. To accurately extract the DC component of the transmitting path, this embodiment uses the following steps in conjunction with the DC component detection module to achieve interference suppression:

[0116] First, the DC component of the receiving path is pre-calibrated and compensated. Specifically, before calibrating the DC component of the transmitting path, the DC component of the receiving path is calibrated in the state of no radio frequency input signal to obtain the DC compensation code of the receiving path. When calibrating the DC component of the transmitting path, the compensation code is loaded first to minimize the impact of the local oscillator leakage of the receiving path itself.

[0117] Secondly, interference signals are separated using a notch filter: by configuring... Figure 5 The notch filter parameters of the module shown attenuate the frequency energy corresponding to the transmitted single-tone signal and the image signal to a sufficiently low level. At this time, the output signal of the notch filter is the interference signal after filtering out the DC component.

[0118] Finally, the difference operation extracts the target DC component: by subtracting the original signal from the notch filter output signal, the DC component caused only by the local oscillator leakage of the transmission path can be separated, which is the "Rx DC OUT" output by the module.

[0119] In this embodiment, the DC component detection module achieves separation of the target DC component and the interference signal through the coordinated operation of the notch filter and the subtractor, thereby accurately extracting the transmitted DC component of the transmission path.

[0120] It should be noted that during the DC component calibration phase of the receiving path, the receiving path is in a state with no RF input signal. At this time, the DC component detection module is also used to detect the transmitted DC component. Specifically, this module can be configured in averaging mode.

[0121] By blocking the input of the low-noise amplifier (LNA), the signal acquired by the ADC is made to be only the DC signal of the receiving path itself; at this time, the notch filter unit can be turned off, and the data acquired by the ADC can be directly averaged to obtain a stable received DC residual signal (corresponding to the received DC component).

[0122] Therefore, the DC component detection module shown in Figure 5 can simultaneously adapt to the DC component detection requirements of both the receiving and transmitting paths, ensuring both the extraction accuracy of the DC component and improving calibration efficiency.

[0123] like Figure 6 As shown, this application also provides a radio frequency transceiver, the radio frequency transceiver comprising: a signal generation module for generating a digital baseband signal; a transmission path including a transmission compensation module, the transmission compensation module using the transmission path compensation code obtained in any of the above embodiments to compensate for the local oscillator leakage of the transmission path; a reception path including a reception compensation module, the reception compensation module using the reception path compensation code obtained in any of the above embodiments to compensate for the local oscillator leakage of the reception path; and a local oscillator module for providing a local oscillator signal for the transmission path and the reception path.

[0124] In summary, this application provides a method, apparatus, and radio frequency transceiver for local oscillator leakage calibration. Through a self-loop architecture, a DC component detection module, and a scheme of calibrating the received DC component first and then calibrating the transmitted DC component, it has at least the following beneficial effects.

[0125] 1. Eliminate dependence on external equipment and significantly reduce mass production and testing costs: The self-loop architecture formed by external coupling of the transmitting and receiving paths eliminates the need for external equipment such as ATE machines to provide a signal source. It enables self-transmission and self-reception of the transmitting signal and accurate compensation for local oscillator leakage in both the receiving and transmitting paths, completely solving the problem of dependence on external measuring instruments or dedicated measuring circuits in traditional calibration. At the same time, the local oscillator leakage in the transmitting path can be compensated and calibrated by a digital notch filter without the need to reconstruct complex circuits, greatly simplifying hardware design and reducing hardware costs and environmental adaptation costs in the chip R&D and mass production stages.

[0126] 2. Optimized calibration process and efficiency: Adopting the logic of "calibrating the receiver first and then calibrating the transmitter," the interference of the receiver's own local oscillator leakage on the transmitter calibration can be eliminated in advance, improving calibration accuracy. At the same time, the DC component detection module supports two modes: averaging method and notch filter. The averaging method can improve the stability of DC detection in scenarios where there is no input at the receiver, while the notch filter can accurately filter out interference signals to extract the transmitted DC component, ensuring the reliability of detection at different calibration stages. After superimposing fast algorithms such as three-way search, the optimal solution can be located without traversing all compensation codes, which greatly simplifies the calibration logic and significantly shortens the calibration time, making it fully adaptable to the needs of time-sensitive scenarios such as power-on checks and self-calibration.

[0127] 3. Supports dynamic self-calibration to ensure long-term stable performance of the chip: The calibration scheme of this application supports self-test and self-calibration functions after the chip is powered on. Even if the chip experiences aging drift during long-term service, dynamic compensation can still be completed by re-executing the calibration process, continuously ensuring the local oscillator leakage suppression effect and RF performance indicators, effectively resisting the performance degradation caused by chip aging, and extending the product service life and reliability.

[0128] 4. Simplify calibration operation logic and improve mass production testing efficiency: The entire calibration process relies on a self-loop architecture and integrated digital circuits to achieve fully automatic execution, without the need for manual intervention to adjust external instruments or the test environment, which greatly simplifies the calibration operation process; combined with the time reduction brought by fast algorithms, it can significantly improve the test throughput in the chip mass production stage and further reduce the mass production testing cost.

[0129] The scope of protection of the local oscillator leakage calibration method for radio frequency transceivers described in this application is not limited to the execution order of the steps listed in this embodiment. Any solution implemented by adding, subtracting, or replacing steps in the prior art based on the principles of this application is included within the scope of protection of this application.

[0130] The calibration device provided in this application embodiment can implement the calibration method described in this application. However, the implementation device of the calibration method described in this application includes, but is not limited to, the structure of the calibration device listed in this embodiment. Any structural modifications and substitutions of the prior art made based on the principles of this application are included within the protection scope of this application.

[0131] In the embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, or methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules / units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or units may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of apparatuses or modules or units may be electrical, mechanical, or other forms.

[0132] The modules / units described as separate components may or may not be physically separate. The components shown as modules / units may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules / units can be selected to achieve the objectives of the embodiments of this application, depending on actual needs. For example, the functional modules / units in the various embodiments of this application may be integrated into one processing module, or each module / unit may exist physically separately, or two or more modules / units may be integrated into one module / unit.

[0133] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0134] The descriptions of the processes or structures corresponding to the above figures each have their own emphasis. For parts of a process or structure that are not described in detail, please refer to the relevant descriptions of other processes or structures.

[0135] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A method for calibrating the local oscillator leakage of a radio frequency transceiver, characterized in that, The radio frequency transceiver includes a transmitting path, a receiving path, and a local oscillator module. The local oscillator module provides a local oscillator signal for the transmitting path and the receiving path. Local oscillator leakage exists in the transmitting path and / or the receiving path. The calibration method includes: When the receiving path is in a state of no radio frequency input signal, a receiving path compensation code corresponding to at least one receiving gain level is determined; the receiving path compensation code is used to compensate for the local oscillator leakage of the receiving path. When the transmitting path and the receiving path are in the open state, the transmitting path and the receiving path are connected to form a self-looping path. The transmitting path compensation code corresponding to multiple transmitting gain levels in the transmitting path is determined according to the receiving path compensation code corresponding to the selected receiving gain level. The transmitting path compensation code is used to compensate for the local oscillator leakage of the transmitting path.

2. The calibration method according to claim 1, characterized in that, Determining the receive path compensation code corresponding to the receive gain level includes: At a certain receiving gain level, the codewords of the compensation code are adjusted and the receiving DC component corresponding to each codeword is obtained. The codeword corresponding to the receiving DC component that is less than a first threshold is selected as the receiving path compensation code corresponding to that receiving gain level.

3. The calibration method according to claim 2, characterized in that, Selecting the codeword corresponding to the received DC component that is less than the first threshold as the receive path compensation code for the receive gain level includes: selecting the codeword corresponding to the smallest received DC component as the receive path compensation code for the receive gain level.

4. The calibration method according to claim 1, characterized in that, The receiving path compensation code includes in-phase compensation code and quadrature compensation code. Adjusting the codewords of the compensation code and obtaining the received DC component corresponding to each codeword, and selecting the codeword corresponding to the received DC component less than a first threshold as the receiving path compensation code for that receiving gain level includes: The codeword of the fixed in-phase compensation code is used as the initial value. The codeword of the quadrature compensation code is scanned within a preset first range to determine the first quadrature compensation code that minimizes the received DC component. Based on the first quadrature compensation code, scan the codeword of the in-phase compensation code to determine the first in-phase compensation code that minimizes the received DC component. Based on the first in-phase compensation code, the codewords of the quadrature compensation code are scanned twice within a preset second range to determine the second quadrature compensation code that minimizes the received DC component, wherein the coverage area of ​​the first range is larger than the coverage area of ​​the second range. The second orthogonal compensation code and the first in-phase compensation code are selected as the receiving path compensation codes corresponding to the receiving gain level.

5. The calibration method according to claim 1, characterized in that, Determining the transmission path compensation code corresponding to multiple transmission gain levels in the transmission path includes: The local oscillator leakage of the receiving path is compensated according to the selected receiving gain level and the corresponding receiving compensation code; At a transmission gain level, the codewords of the compensation code are adjusted and the transmission DC components corresponding to each codeword are obtained. The codewords corresponding to the transmission DC components that are less than the second threshold are selected as the transmission path compensation codes corresponding to the transmission gain level.

6. The calibration method according to claim 5, characterized in that, Obtaining the transmitted DC component corresponding to each of the codewords includes: The original received signal is filtered using a notch filter to obtain the filtered signal. The original received signal is subtracted from the filtered signal to obtain the transmitted DC component corresponding to each codeword.

7. The calibration method according to claim 1, characterized in that, The calibration method further includes: determining the selected receive gain level based on the line attenuation of the self-loop path.

8. The calibration method according to claim 1, characterized in that, The method further includes performing in-phase quadrature compensation on the digital baseband signals in the transmitting path and the receiving path.

9. A local oscillator leakage calibration device for a radio frequency transceiver, characterized in that, The device includes a transmitting path, a receiving path, and a local oscillator module. The local oscillator module is used to provide a local oscillator signal for the transmitting path and the receiving path. The transmitting path and the receiving path are connected to form a self-looping path. The transmission path includes: Signal generation module, used to generate digital baseband signals; A transmission compensation module is used to compensate for the transmitted DC component of the transmission path; The transmitting module is used to process the digital baseband signal and related signals for transmitting the digital baseband signal; The receiving path includes: The receiving module is used to receive and process the related signals of the digital baseband signal; A receiving compensation module is used to compensate for the received DC component of the receiving path; The detection module is used to detect the transmitted DC component and the received DC component.

10. A radio frequency transceiver, characterized in that, The radio frequency transceiver includes: Signal generation module, used to generate digital baseband signals; A transmission path, including a transmission compensation module, wherein the transmission compensation module uses the transmission path compensation code obtained by the calibration method of any one of claims 1-8 to compensate for the local oscillator leakage of the transmission path; A receiving path includes a receiving compensation module, wherein the receiving compensation module uses the receiving path compensation code obtained by the calibration method according to any one of claims 1-8 to compensate for the local oscillator leakage of the receiving path; The local oscillator module is used to provide local oscillator signals for the transmitting path and the receiving path.

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