RFID reader / writer system and method for controlling transmit power thereof

Abstract

An RFID reader / writer system, and a method for controlling the transmit power thereof. The system comprises a transmission link power drive circuit and a radio frequency power calibration circuit. The transmission link power drive circuit at least comprises a digital baseband and a gain register thereof, and the radio frequency power calibration circuit comprises a main controller and a temperature sensor. An input end of the temperature sensor is connected to the transmission link power drive circuit, and an output end is connected to an input end of the main controller, the temperature sensor being used to detect the real-time board temperature of the transmission link power drive circuit, and send the real-time board temperature to the main controller. The main controller can determine, according to the received real-time board temperature, whether to adjust the gain of the transmission link power drive circuit, and, when it is determined to perform adjustment, adjust the gain of the digital baseband and the gain register thereof according to the real-time board temperature, so as to adjust the actual transmit power of the transmission link power drive circuit.

Description

RFID reader / writer system and transmission power control method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 31, 2023, with application number 202310948063.9 and invention name “A RFID reader system and its transmission power control method”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of radio frequency technology, and in particular to an RFID reader-writer system and a transmission power control method thereof. Background Art

[0003] An ultra-high frequency radio frequency identification (RFID) communication system consists of two main components: an RFID reader and an RFID tag. The RFID reader is an active system and can be powered directly by an external power source, while the tag is a passive system and cannot be directly powered by an external power source. The RFID reader transmits electromagnetic waves into space through its antenna, while the RFID tag receives these waves through its antenna and converts them into electrical energy to power itself. In practical applications, the distance between the RFID tag and the reader can affect communication quality. For example, when the distance between the two is long, electromagnetic waves attenuate significantly over long distances, requiring the RFID reader to emit high-power electromagnetic waves to activate the tag and ensure proper communication. However, when the distance between the two is short, electromagnetic waves attenuate less over short distances, requiring the RFID reader to emit low-power electromagnetic waves to activate only nearby tags and avoid activating more distant ones, thereby reducing the reader system's power consumption. This requires adjustable output power to meet the requirements of communication scenarios at varying distances.

[0004] Currently, the RFID transmission channel primarily consists of eight components: a baseband DAC, a mixer, an on-chip power amplifier, an off-chip power amplifier, a directional coupler, a power detector, an analog-to-digital converter (ADC), and a main controller. RF power calibration and detection modules, comprised of the directional coupler, power detector, ADC, and main controller, enable RF power detection and closed-loop control. However, this circuit component increases circuit complexity, board layout area, and hardware cost, hindering miniaturization. Furthermore, due to the influence of ambient temperature, PCB manufacturing process factors, and varying operating frequencies, the power detector's RF power-to-voltage fitting formula exhibits certain deviations, resulting in deviations in its output power and, in turn, lowering the reader's output power regulation accuracy.

[0005] Summary of the Invention

[0006] The purpose of this application is to solve at least one of the above-mentioned technical defects, especially the technical defects that the radio frequency power calibration and detection function module in the RFID reader system in the prior art increases the complexity of the circuit, the circuit layout area and the hardware cost, which is not conducive to miniaturization requirements and affects the output power adjustment accuracy of the reader.

[0007] The present application provides an RFID reader / writer system, the system comprising a transmission link power driving circuit and a radio frequency power calibration circuit;

[0008] Wherein, the transmission link power driving circuit includes at least a digital baseband and its gain register, and the radio frequency power calibration circuit includes a main controller and a temperature sensor;

[0009] The temperature sensor has an input end connected to the transmit link power driving circuit, and an output end connected to an input end of the main controller, for detecting a real-time onboard temperature of the transmit link power driving circuit and sending the real-time onboard temperature to the main controller;

[0010] The output end of the main controller is connected to the digital baseband and its gain register, and is used to determine whether to adjust the gain of the transmission link power driving circuit based on the received real-time onboard temperature, and when determining to adjust, adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature.

[0011] Optionally, the process of the main controller determining whether to adjust the gain of the transmit link power driving circuit according to the received real-time onboard temperature includes:

[0012] The main controller determines a target transmit power of the transmit link power driving circuit and a target temperature range for the target transmit power, and compares the received real-time onboard temperature with the target temperature range;

[0013] When the main controller determines that the real-time onboard temperature is within the target temperature range, it determines not to adjust the gain of the transmission link power driving circuit; when it determines that the real-time onboard temperature is not within the target temperature range, it determines to adjust the gain of the transmission link power driving circuit.

[0014] Optionally, the process of the main controller adjusting the gain of the digital baseband and its gain register according to the real-time onboard temperature includes:

[0015] The main controller determines a power compensation value of the actual transmission power of the transmission link power driving circuit according to the real-time onboard temperature, and adjusts the gain of the digital baseband and its gain register according to the power compensation value.

[0016] Optionally, the transmission link power driving circuit further includes a baseband DAC, a mixer and its gain register, a driving power amplifier and its gain register, a filter, a final-stage adjustable gain power amplifier, and a directional coupler connected in sequence;

[0017] The input end of the baseband DAC is connected to the output end of the digital baseband and its gain register.

[0018] The present application also provides a transmission power control method, which is applied to a main controller in the RFID reader / writer system described in any one of the above embodiments. The method includes:

[0019] When transmitting electromagnetic waves, determining a target transmit power of a transmit link power driver circuit, an actual transmit power after configuring the gain of the transmit link power driver circuit according to the target transmit power, and a real-time onboard temperature of the transmit link power driver circuit detected by a temperature sensor when transmitting electromagnetic waves according to the actual transmit power;

[0020] determining whether the real-time onboard temperature is within a target temperature range for the target transmit power;

[0021] If the real-time onboard temperature is within the target temperature range, exit the power control link;

[0022] If the real-time onboard temperature is not within the target temperature range, a power compensation value of the actual transmit power is determined based on the real-time onboard temperature, and the gain of the digital baseband and its gain register in the transmit link power driving circuit is adjusted according to the power compensation value. Then, the process returns to determining the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power and subsequent steps until the power error between the actual transmit power and the target transmit power does not exceed a preset error threshold.

[0023] Optionally, the determining the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power includes:

[0024] Obtaining a pre-configured target transmission link gain configuration table corresponding to the target transmission power;

[0025] After configuring the gain of the transmission link power driving circuit according to the target transmission link gain configuration table, the actual transmission power of the transmission link power driving circuit after the gain is configured is obtained.

[0026] Optionally, determining the power compensation value of the actual transmit power according to the real-time onboard temperature and the target temperature range includes:

[0027] Determining a fitting formula between the actual transmit power at different temperatures and the radio frequency power at a preset temperature, wherein the fitting formula includes a power compensation value between the actual transmit power at different temperatures and the radio frequency power at the preset temperature;

[0028] After comparing the actual transmit power at the real-time onboard temperature with the fitting formula, a power compensation value of the actual transmit power at the real-time onboard temperature is determined.

[0029] Optionally, determining a fitting formula between actual transmit power at different temperatures and radio frequency power at a preset temperature includes:

[0030] Placing the transmit link power drive circuit in a constant temperature test chamber, and controlling the RF output and the chamber temperature of the constant temperature test chamber by PC software;

[0031] The temperature sensor is used to obtain the real-time temperature of the transmission link power driving circuit when the radio frequency is output at different test chamber temperatures and the actual transmission power collected by the spectrum analyzer at the real-time temperature;

[0032] The power compensation value between the actual transmission power at different test chamber temperatures and the RF power at the preset temperature is obtained by subtracting the actual transmission power at different test chamber temperatures from the RF power at the preset temperature;

[0033] According to the power compensation value between the actual transmission power at different test chamber temperatures and the radio frequency power at the preset temperature, a fitting formula between the actual transmission power at different temperatures and the radio frequency power at the preset temperature is determined.

[0034] Optionally, adjusting the gain of a digital baseband and a gain register thereof in the transmit link power driving circuit according to the power compensation value includes:

[0035] Determining a pre-configured target transmission link gain configuration table corresponding to the target transmission power, wherein the target transmission link gain configuration table includes a target temperature range corresponding to the target transmission power;

[0036] Determining, based on the power compensation value and the target transmission link gain configuration table, a gain step relationship between a digital baseband and its gain register in the transmission link power driving circuit and the power compensation value;

[0037] The gain of the digital baseband and its gain register are adjusted according to the gain step relationship.

[0038] Optionally, determining a pre-configured target transmit link gain configuration table corresponding to the target transmit power includes:

[0039] Obtaining a pre-configured initial transmit link gain configuration table for each gain driving unit of the transmit link power driving circuit, and multiple target transmit powers obtained by configuring the gains of each gain driving unit of the transmit link power driving circuit according to the initial transmit link gain configuration table;

[0040] After sequentially obtaining the gains of the respective gain driving units of the transmit link power driving circuit corresponding to the respective target transmit powers through PC software, each gain driving unit of the transmit link power driving circuit is configured according to the obtained gains, and the actual transmit power output by the transmit link power driving circuit after the configured gains is obtained through a spectrum analyzer;

[0041] Determining whether the actual transmit power is equal to the corresponding target transmit power;

[0042] If not, adjusting the initial transmit link gain configuration table according to the deviation between the actual transmit power and the target transmit power, and returning to the steps of sequentially obtaining the gains of the respective gain driving units of the transmit link power driving circuit corresponding to the respective target transmit powers through PC software and subsequent steps;

[0043] If they are equal, the target temperature range corresponding to the target transmit power detected by the temperature sensor is obtained, and the target temperature range corresponding to the target transmit power is sent to the PC software for storage. Until all target transmit powers are calibrated, all target transmit powers and corresponding target temperature ranges, and the gains of each gain driving unit of the transmit link power driving circuit are sorted out by the PC software to form a target transmit link gain configuration table.

[0044] It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

[0045] The present application provides an RFID reader / writer system and a transmission power control method thereof, the system including a transmission link power driving circuit and a radio frequency power calibration circuit; wherein the transmission link power driving circuit includes at least a digital baseband and its gain register, and the radio frequency power calibration circuit includes a main controller and a temperature sensor; the input end of the temperature sensor is connected to the transmission link power driving circuit, and the output end is connected to the input end of the main controller, for detecting the real-time onboard temperature of the transmission link power driving circuit and sending the real-time onboard temperature to the main controller; the output end of the main controller is connected to the digital baseband and its gain register, so that the main controller can determine whether to adjust the gain of the transmission link power driving circuit based on the received real-time onboard temperature, and when determining to adjust, adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature, thereby adjusting the actual transmission power of the transmission link power driving circuit. This process can achieve precise adjustment and stable output of the reader's RF emission power through a low-cost hardware and software system consisting of a temperature sensor and a main controller. Compared with the RF power calibration and detection function module composed of a power detector, an analog-to-digital converter ADC and a main controller in the prior art, this application greatly reduces the complexity and hardware cost of the RF circuit, and can also reduce the circuit layout area, thereby making the hardware module more miniaturized; and after the application obtains the real-time onboard temperature of the transmission link power drive circuit through the temperature sensor, the main controller directly adjusts the gain of the digital baseband and its gain register based on the real-time onboard temperature, thereby avoiding the use of a power detector to detect the output power, resulting in low output power adjustment accuracy of the reader. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0047] FIG1 is a schematic structural diagram of an RFID reader / writer system provided in an embodiment of the present application;

[0048] FIG2 is a circuit connection diagram of a transmit link power drive circuit, a main controller, and a temperature sensor provided in an embodiment of the present application;

[0049] FIG3 is a flow chart of a transmission power control method provided in an embodiment of the present application;

[0050] FIG4 is a schematic diagram of power output when the temperature compensation function of the transmit link power gain driving circuit is not enabled according to an embodiment of the present application;

[0051] FIG5 is a schematic diagram of power output when the temperature compensation function of the transmit link power gain driving circuit is enabled according to an embodiment of the present application;

[0052] FIG6 is a schematic diagram of a circuit structure for determining a fitting formula according to an embodiment of the present application;

[0053] FIG7 is a schematic diagram of fitting formulas at different temperatures provided in an embodiment of the present application;

[0054] FIG8 is a schematic diagram of the gain step relationship of the digital baseband and its gain register in the transmit link power driving circuit provided by an embodiment of the present application;

[0055] FIG9 is a schematic diagram of a circuit structure when configuring a target transmission link gain configuration table according to an embodiment of the present application;

[0056] FIG10 is a diagram showing the relationship between the initial transmission link gain configuration table and the corresponding target transmission power according to an embodiment of the present application;

[0057] FIG11 is a schematic diagram of the structure of the target transmission link gain configuration table provided in an embodiment of the present application. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] At present, the RFID transmission channel is mainly composed of eight parts: baseband DAC, mixer, on-chip power amplifier, off-chip power amplifier, directional coupler, power detector, analog-to-digital converter ADC and main controller. The RF power calibration and detection function module composed of directional coupler, power detector, analog-to-digital converter ADC and main controller is used to realize the detection of RF emission power and closed-loop control adjustment. However, this part of the circuit unit increases the complexity of the circuit, the circuit board area and the hardware cost, which is not conducive to miniaturization requirements. In addition, due to the influence of the working environment temperature factors, PCB plate making process factors and different working frequency factors, the fitting formula of the RF power and voltage of the power detector has a certain deviation, which makes its output power also have a certain deviation, which leads to low output power adjustment accuracy of the reader. Based on this, the present application proposes the following technical solutions, see below for details:

[0060] In one embodiment, as shown in FIG1 , FIG1 is a schematic structural diagram of an RFID reader-writer system provided in an embodiment of the present application; the present application provides an RFID reader-writer system, the system including a transmission link power driving circuit and a radio frequency power calibration circuit.

[0061] The transmission link power driving circuit includes at least a digital baseband and a gain register thereof, and the radio frequency power calibration circuit includes a main controller and a temperature sensor.

[0062] The input end of the temperature sensor is connected to the transmission link power driving circuit, and the output end is connected to the input end of the main controller, for detecting the real-time onboard temperature of the transmission link power driving circuit and sending the real-time onboard temperature to the main controller.

[0063] The output end of the main controller is connected to the digital baseband and its gain register, and is used to determine whether to adjust the gain of the transmission link power driving circuit based on the received real-time onboard temperature, and when determining to adjust, adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature.

[0064] In this embodiment, the RFID reader system may include a transmission link power driving circuit and a radio frequency power calibration circuit; wherein the transmission link power driving circuit refers to a link in the RFID reader system composed of at least one gain driving unit that can transmit electromagnetic waves of a certain power, and the radio frequency power calibration circuit of this application refers to a circuit that adjusts the gain in the gain driving unit of the transmission link power driving circuit according to the real-time temperature of the transmission link power driving circuit so that the transmission power of the transmission link power driving circuit is adjusted.

[0065] Specifically, as shown in FIG1 , the RFID reader system of the present application uses the above-mentioned transmission link power drive circuit and the RF power calibration circuit for reading and writing. The transmission link power drive circuit may include at least a digital baseband and its gain register, and the RF power calibration circuit may include a main controller and a temperature sensor. The temperature sensor may be connected to the transmission link power drive circuit so that the temperature sensor can detect the real-time onboard temperature of the transmission link power drive circuit. In order to better adjust the gain of the transmission link power drive circuit, the output end of the temperature sensor may be connected to the input end of the main controller, and the output end of the main controller may be connected to the digital baseband and its gain register in the transmission link power drive circuit. The main controller may be configured to receive the real-time onboard temperature sent by the temperature sensor and determine whether to adjust the gain of the transmission link power drive circuit based on the real-time onboard temperature. When it is determined that the gain of the transmission link power drive circuit is to be adjusted, the gain of the digital baseband and its gain register in the transmission link power drive circuit may be adjusted according to the real-time onboard temperature. At this time, the transmission link power drive circuit may retransmit the RF power according to the adjusted gain, thereby realizing RF power detection and closed-loop control adjustment.

[0066] For example, the present application can determine in advance through experiments the temperature corresponding to when the transmission link power driving circuit transmits different RF powers, and then compare the real-time onboard temperature with the temperature corresponding to the current RF power, so that it can be determined based on the comparison result whether to adjust the gain of the transmission link power driving circuit; or, the present application can also calculate the corresponding RF power based on the real-time onboard temperature, and compare the calculated RF power with the RF power actually emitted by the transmission link power driving circuit, so that it can also be determined based on the comparison result whether to adjust the gain of the transmission link power driving circuit; further, the present application can also determine whether the current operating temperature of the transmission link power driving circuit exceeds the ideal operating temperature based on the real-time onboard temperature. If it exceeds, it indicates that the gain of the transmission link power driving circuit needs to be adjusted. If it does not exceed, it indicates that the gain of the transmission link power driving circuit does not need to be adjusted; of course, the present application can also determine whether the gain of the transmission link power driving circuit needs to be adjusted by other methods, which will not be elaborated here.

[0067] When determining to adjust the gain of the transmit link power driver circuit, the main controller can adjust the gain of the digital baseband and its gain register in the transmit link power driver circuit according to the real-time onboard temperature. For example, the main controller can determine the gain adjustment value of the digital baseband and its gain register according to the real-time onboard temperature, and then adjust the gain of the digital baseband and its gain register according to the gain adjustment value; the main controller can also determine the current ideal output RF power according to the real-time onboard temperature, and adjust the gain of the digital baseband and its gain register according to the ideal output RF power; or the main controller can also determine the power compensation value of the current output RF power according to the real-time onboard temperature, and determine the gain adjustment value of the digital baseband and its gain register according to the power compensation value, so that the gain of the digital baseband and its gain register can also be adjusted.

[0068] It can be understood that the digital baseband and its gain register in the transmission link power driving circuit of the present application are mainly responsible for fine-tuning the gain in the transmission link so that the RF power emitted by the transmission link meets certain power requirements. For example, the gain register in the digital baseband and its gain register of the present application is responsible for adjusting the gain of the digital baseband, and the digital baseband is responsible for amplifying the digital baseband signal before it is modulated to the carrier signal. After the digital baseband and its gain register are connected to the main controller, the main controller can adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature. In this way, the size of the RF power emitted by the transmission link power driving circuit can be quickly adjusted, and the gain of multiple gain driving units can be adjusted at the same time, which causes the adjustment time to be too long.

[0069] It should also be noted that the main controller in this application refers to the instruction controller that plays a major role within a given time interval in a computer with multiple instruction controllers. The main controller in this application can be replaced by an MCU (microcontroller unit), also known as a single-chip microcomputer (Single Chip Microcomputer) or a single-chip microcomputer. Generally, MCUs can be divided into 1-bit, 4-bit, 8-bit, 16-bit, 32-bit or even 64-bit single-chip microcomputers according to the number of data bits processed by their basic operations. 8-bit, 16-bit and 32-bit single-chip microcomputers are more commonly used. According to their memory type, they can be divided into two types: no on-chip ROM type and on-chip ROM type. This application can be selected according to actual conditions and is not limited here.

[0070] In the above embodiment, the system includes a transmission link power driving circuit and a radio frequency power calibration circuit; wherein, the transmission link power driving circuit includes at least a digital baseband and its gain register, and the radio frequency power calibration circuit includes a main controller and a temperature sensor; the input end of the temperature sensor is connected to the transmission link power driving circuit, and the output end is connected to the input end of the main controller, for detecting the real-time onboard temperature of the transmission link power driving circuit and sending the real-time onboard temperature to the main controller; the output end of the main controller is connected to the digital baseband and its gain register, so that the main controller can determine whether to adjust the gain of the transmission link power driving circuit based on the received real-time onboard temperature, and when determining to adjust, adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature, so as to adjust the actual transmission power of the transmission link power driving circuit. This process can achieve precise adjustment and stable output of the reader's RF emission power through a low-cost hardware and software system consisting of a temperature sensor and a main controller. Compared with the RF power calibration and detection function module composed of a power detector, an analog-to-digital converter ADC and a main controller in the prior art, this application greatly reduces the complexity and hardware cost of the RF circuit, and can also reduce the circuit layout area, thereby making the hardware module more miniaturized; and after the application obtains the real-time onboard temperature of the transmission link power drive circuit through the temperature sensor, the main controller directly adjusts the gain of the digital baseband and its gain register based on the real-time onboard temperature, thereby avoiding the use of a power detector to detect the output power, resulting in low output power adjustment accuracy of the reader.

[0071] In one embodiment, the process of the main controller determining whether to adjust the gain of the transmit link power driver circuit according to the received real-time onboard temperature may include:

[0072] The main controller determines a target transmit power of the transmit link power driving circuit and a target temperature range of the target transmit power, and compares the received real-time onboard temperature with the target temperature range.

[0073] When the main controller determines that the real-time onboard temperature is within the target temperature range, it determines not to adjust the gain of the transmission link power driving circuit; when it determines that the real-time onboard temperature is not within the target temperature range, it determines to adjust the gain of the transmission link power driving circuit.

[0074] In this embodiment, when the main controller determines whether to adjust the gain of the transmission link power driving circuit based on the received real-time onboard temperature, it can first determine the target transmission power of the transmission link power driving circuit and the target temperature range corresponding to the target transmission power. Then, the main controller can compare the real-time onboard temperature with the target temperature range to determine whether the real-time onboard temperature is within the target temperature range. If so, it means that the power error between the actual transmission power of the transmission link power driving circuit when currently transmitting electromagnetic waves and the target transmission power is small, or the actual transmission power is the same as the target transmission power, and at this time there is no need to adjust the gain of the transmission link power driving circuit; if not, it means that the power error between the real-time transmission power of the transmission link power driving circuit when currently transmitting electromagnetic waves and the target transmission power is large, and at this time it is necessary to adjust the gain of the transmission link power driving circuit so that the power error between the actual transmission power of the adjusted transmission link power driving circuit when transmitting electromagnetic waves and the target transmission power is small or the same as the target transmission power.

[0075] It is understandable that before the transmission link power driving circuit of the present application transmits electromagnetic waves, the main controller can configure the gain of the transmission link power driving circuit according to the relevant configuration so that the transmission link power driving circuit can output electromagnetic waves with the target transmission power. However, since the transmission link power driving circuit needs to perform modulation, demodulation, amplification, filtering and other related operations through related circuits during the process of transmitting electromagnetic waves, the power value of the actual transmission power output by the transmission link power driving circuit is not necessarily consistent with or close to the power value of the target transmission power. Therefore, the present application uses a temperature sensor to detect the real-time onboard temperature of the transmission link power driving circuit, so that the main controller can monitor the power transmission status of the transmission link power driving circuit according to the real-time onboard temperature and make timely adjustments.

[0076] In one embodiment, the process of the main controller adjusting the gain of the digital baseband and its gain register according to the real-time onboard temperature may include:

[0077] The main controller determines a power compensation value of the actual transmission power of the transmission link power driving circuit according to the real-time onboard temperature, and adjusts the gain of the digital baseband and its gain register according to the power compensation value.

[0078] In this embodiment, when the main controller adjusts the gain of the digital baseband and its gain register according to the real-time onboard temperature, it can first determine the power compensation value of the actual transmission power of the transmission link power driving circuit according to the real-time onboard temperature, and then adjust the gain of the digital baseband and its gain register according to the power compensation value, so that the actual transmission power of the transmission link power driving circuit can be adjusted.

[0079] It can be understood that the power compensation value here refers to the difference between the actual transmission power at the real-time onboard temperature and the radio frequency power at the preset temperature. In order to improve the accuracy of the radio frequency output power of the RFID reader system under wide temperature working conditions, the present application can pre-configure power compensation at the corresponding temperature for the transmission power calibrated at normal temperature. In this way, when the RFID reader system operates under wide temperature conditions, the present application can also compensate for the actual transmission power by means of power compensation, so as to eliminate the calculation error caused by the real-time onboard temperature exceeding the normal temperature. Furthermore, the preset temperature here can be the temperature at normal temperature, or it can be a temperature set according to the actual working conditions of the reader, such as 20°C, etc., which is not limited here.

[0080] In one embodiment, as shown in Figure 2, Figure 2 is a circuit connection diagram of the transmission link power driving circuit, the main controller, and the temperature sensor provided in an embodiment of the present application; the transmission link power driving circuit also includes a baseband DAC, a mixer and its gain register, a driving power amplifier and its gain register, a filter, a final-stage adjustable gain power amplifier, and a directional coupler connected in sequence.

[0081] The input end of the baseband DAC is connected to the output end of the digital baseband and its gain register.

[0082] In this embodiment, as shown in Figure 2, the transmission link power driving circuit may include not only a digital baseband and its gain register, but also a baseband DAC, a mixer and its gain register, a driving power amplifier and its gain register, a filter, a final-stage adjustable gain power amplifier and a directional coupler connected in sequence. In this way, each gain driving unit adjusts its own gain through its gain register or the power amplifier itself, so that the power of the final transmission link power driving circuit when transmitting electromagnetic waves can meet the requirements of different application scenarios.

[0083] It can be understood that the baseband DAC here can convert the amplified digital baseband signal into a radio frequency signal, and the mixer and its gain register can multiply the radio frequency signal emitted by the baseband DAC with the local oscillator signal and then amplify it. The driving power amplifier and its gain register can drive the output power of the mixer and its gain register. The electronic component of the gain; and the final stage adjustable gain power amplifier can further amplify the output power of the driving power amplifier and its gain register; the directional coupler can output the electromagnetic wave signal amplified by the final stage adjustable gain power amplifier to the antenna, and at the same time can couple the electromagnetic wave signal received from the antenna to the electronic component at the receiver end.

[0084] In one embodiment, as shown in FIG3 , FIG3 is a flow chart of a transmission power control method provided in an embodiment of the present application. The present application also provides a transmission power control method, which is applied to a main controller in an RFID reader / writer system in any of the above embodiments. The method may include:

[0085] S110: When transmitting electromagnetic waves, determine the target transmission power of the transmission link power driving circuit, the actual transmission power after configuring the gain of the transmission link power driving circuit according to the target transmission power, and the real-time onboard temperature of the transmission link power driving circuit detected by the temperature sensor when transmitting electromagnetic waves according to the actual transmission power.

[0086] S120: Determine whether the real-time onboard temperature is within the target temperature range of the target transmit power; if the real-time onboard temperature is within the target temperature range, execute S130; if the real-time onboard temperature is not within the target temperature range, execute S140.

[0087] S130: Exit the power control link.

[0088] S140: Determine the power compensation value of the actual transmit power based on the real-time onboard temperature, and adjust the gain of the digital baseband and its gain register in the transmit link power driving circuit according to the power compensation value, then return to execute the step of determining the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power in S110, and the real-time onboard temperature of the transmit link power driving circuit detected by the temperature sensor when transmitting electromagnetic waves according to the actual transmit power, as well as S120 to S140.

[0089] In this embodiment, as shown in FIG3 , when the RFID reader system needs to transmit electromagnetic waves, the main controller can first determine the target transmission power of the transmission link power driving circuit when transmitting electromagnetic waves this time, so that the actual transmission power after the gain of the transmission link power driving circuit is configured according to the target transmission power can be determined, as well as the real-time onboard temperature of the transmission link power driving circuit detected by the temperature sensor when the electromagnetic waves are transmitted according to the actual transmission power. Then, the main controller can determine whether the real-time onboard temperature is within the target temperature range of the target transmission power. If so, there is no need to adjust the gain of the transmission link power driving circuit, and the power control link can be exited at this time; if not, then It is necessary to adjust the gain of the transmission link power driving circuit. At this time, the power compensation value of the actual transmission power can be determined first according to the real-time onboard temperature, and then the gain of the digital baseband and its gain register can be adjusted according to the power compensation value. After the adjustment, the actual transmission power after the gain of the transmission link power driving circuit is configured according to the target transmission power, as well as the real-time onboard temperature when the electromagnetic wave is transmitted according to the actual transmission power, are re-determined. In this way, the main controller can continue to determine whether to adjust the gain of the current transmission link power driving circuit according to the real-time onboard temperature, so that the actual transmission power finally output by the transmission link power driving circuit approaches the target transmission power.

[0090] It is understandable that since the working state of the gain driving unit in the transmission link power driving circuit is related to the temperature, the difference in loss after the same power is processed by the gain driving unit at different temperatures is also different. Therefore, the present application can pre-configure the target temperature range corresponding to each target transmission power of the transmission link power driving circuit according to a certain temperature configuration strategy, so that after the main controller obtains the real-time onboard temperature sent by the temperature sensor, it can compare the real-time onboard temperature with the target temperature range of the target transmission power, and determine whether the real-time onboard temperature of the current transmission link power driving circuit is within the target temperature range, so that it can be determined whether the gain of the current transmission link power driving circuit needs to be adjusted. It should be noted that the target temperature range here can be a certain temperature value or a certain temperature range, which is not limited here.

[0091] The beneficial effects of the transmission power control method of the present application will be explained below through Figures 4 and 5. Schematically, as shown in Figures 4 and 5, Figure 4 is a schematic diagram of the power output when the temperature compensation function of the transmission link power gain driving circuit is not enabled, and Figure 5 is a schematic diagram of the power output when the temperature compensation function of the transmission link power gain driving circuit is enabled. Comparing Figures 4 and 5, it can be seen that when the temperature compensation function is enabled, the maximum power deviation output by the transmission link power gain driving circuit is 0.8, which is lower than the error tolerance of ±1d, and when the temperature compensation function is not enabled, the maximum power deviation output by the transmission link power gain driving circuit is 1.5, which is greater than the error tolerance of ±1d. Therefore, compared with the prior art, the present application can achieve an output power adjustment accuracy of ±1dB for the RFID reader, meeting the conditions of different frequencies and different working environment temperatures (-20°C to 80°C).

[0092] In one embodiment, determining the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power in S110 may include:

[0093] S111: Acquire a pre-configured target transmission link gain configuration table corresponding to the target transmission power.

[0094] S112: After configuring the gain of the transmit link power driving circuit according to the target transmit link gain configuration table, the actual transmit power of the transmit link power driving circuit after the gain is configured is acquired.

[0095] In this embodiment, when determining the actual transmit power of the transmit link power driving circuit, a pre-configured target transmit link gain configuration table corresponding to the target transmit power can be obtained first, and then the gain of the transmit link power driving circuit can be configured according to the target transmit link gain configuration table. After the configuration, the actual transmit power of the transmit link power driving circuit can be obtained.

[0096] The target transmission link gain configuration table of the present application contains the gain configuration information of each gain driving unit in the transmission link power driving circuit under different target transmission powers, as well as the temperature value of the transmission link power driving circuit under different target transmission powers. When the main controller needs to obtain the actual transmission power of the transmission link power driving circuit, it can first call the pre-configured target transmission link gain configuration table to obtain the gain of the transmission link power driving circuit corresponding to the target transmission power, and then configure the transmission link power driving circuit according to the gain, and then obtain the actual transmission power output by the transmission link power driving circuit under the configuration.

[0097] Furthermore, when the main controller needs to determine whether the real-time onboard temperature detected by the current temperature sensor is within the target temperature range of the target transmission power, it can also call the pre-configured target transmission link gain configuration table to obtain the target temperature range corresponding to the target transmission power, and then determine whether to adjust the gain of the transmission link power driving circuit based on the comparison result between the real-time onboard temperature and the target temperature range.

[0098] In one embodiment, determining the power compensation value of the actual transmit power according to the real-time onboard temperature and the target temperature range in S140 may include:

[0099] S141: Determine a fitting formula between actual transmit power at different temperatures and radio frequency power at a preset temperature, wherein the fitting formula includes a power compensation value between actual transmit power at different temperatures and radio frequency power at a preset temperature.

[0100] S142: After comparing the actual transmit power at the real-time onboard temperature with the fitting formula, a power compensation value of the actual transmit power at the real-time onboard temperature is determined.

[0101] In this embodiment, when determining the power compensation value corresponding to the actual transmit power, the present application can first determine a fitting formula between the actual transmit power at different temperatures and the RF power at a preset temperature. Since the fitting formula includes the power compensation value between the actual transmit power at different temperatures and the RF power at the preset temperature, after obtaining the fitting formula between the actual transmit power at different temperatures and the RF power at the preset temperature, the present application can compare the actual transmit power of the transmit link power driving circuit at the real-time onboard temperature with the obtained multiple fitting formulas to determine the power compensation value of the actual transmit power at the real-time onboard temperature.

[0102] It should be noted that the main controller in this application can pre-configure the fitting formula between the actual transmission power at different temperatures and the RF power at a preset temperature, and save it to a specific path. In this way, when determining the power compensation value of the actual transmission power of the transmission link power driving circuit at the real-time onboard temperature, the pre-stored fitting formula between the actual transmission power at different temperatures and the RF power at the preset temperature can be directly called, which saves the time for determining the fitting formula and effectively improves the reading and writing efficiency.

[0103] In one embodiment, as shown in FIG6 , FIG6 is a schematic diagram of a circuit structure for determining a fitting formula according to an embodiment of the present application; the fitting formula for determining the actual transmit power at different temperatures and the RF power at a preset temperature in S141 may include:

[0104] S1410: Placing the transmit link power driving circuit in a constant temperature test chamber, and controlling the radio frequency output and the chamber temperature of the constant temperature test chamber through PC software.

[0105] S1411: Acquire, through the temperature sensor, the real-time temperature of the transmission link power driving circuit during RF output at different test chamber temperatures and the actual transmission power collected by the spectrum analyzer at the real-time temperature.

[0106] S1412: Subtracting the actual transmission power at different test chamber temperatures from the radio frequency power at the preset temperature to obtain a power compensation value between the actual transmission power at different test chamber temperatures and the radio frequency power at the preset temperature.

[0107] S1413: Determine a fitting formula between the actual transmit power at different temperatures and the RF power at the preset temperature based on the power compensation value between the actual transmit power at different test chamber temperatures and the RF power at the preset temperature.

[0108] In this embodiment, as shown in Figure 6, when it is necessary to determine the fitting formula between the actual transmission power at different temperatures and the RF power at a preset temperature, the transmission link power driving circuit of the present application can be placed in a constant temperature test chamber first, and the RF output and the test chamber temperature of the constant temperature test chamber can be controlled by PC software. In this way, the real-time temperature of the transmission link power driving circuit at the RF output at different test chamber temperatures and the actual transmission power collected by the spectrum analyzer or power meter at the real-time temperature can be obtained through the temperature sensor. Then, the present application can make a difference between the actual transmission power at different test chamber temperatures and the RF power at the preset power, so that the power compensation value between the actual transmission power at different test chamber temperatures and the RF power at the preset temperature can be obtained, and then the corresponding fitting formula can be determined based on the power compensation value between the actual transmission power at different test chamber temperatures and the RF power at the preset temperature.

[0109] For example, the present application can use the main controller and the temperature sensor to detect the temperature T of the transmission link power driving circuit in real time, and then compensate the digital baseband and its gain register (DBB_gain) in the transmission link power driving circuit according to the RF power PTX_0 at the preset temperature T0 (20°C). The fitting formula of the actual transmission power output at temperature T and the RF power PTX_0 at temperature T0 (20°C) is shown in Figure 7. Figure 7 is a schematic diagram of the fitting formula at different temperatures provided by an embodiment of the present application; it can be seen from Figure 7 that after the present application obtains the fitting formula between the actual transmission power at different temperatures and the RF power at the preset temperature, the power compensation value of the actual transmission power at the real-time onboard temperature can be quickly determined.

[0110] In one embodiment, adjusting the gain of the digital baseband and its gain register in the transmit link power driving circuit according to the power compensation value in S140 may include:

[0111] S410: Determine a pre-configured target transmission link gain configuration table corresponding to the target transmission power, wherein the target transmission link gain configuration table includes a target temperature range corresponding to the target transmission power.

[0112] S411: Determine, according to the power compensation value and the target transmission link gain configuration table, a gain step relationship between a digital baseband in the transmission link power driving circuit and its gain register and the power compensation value.

[0113] S412: Adjust the gain of the digital baseband and its gain register according to the gain step relationship.

[0114] In this embodiment, when adjusting the gain of the digital baseband and its gain register in the transmit link power driver circuit, the main controller can first determine a preconfigured target transmit link gain configuration table corresponding to the target transmit power. Because the target transmit link gain configuration table contains gain configuration information for each gain driving unit in the transmit link power driver circuit at different target transmit powers, as well as temperature values ​​of the transmit link power driver circuit at different target transmit powers, when the main controller needs to adjust the gain of the digital baseband and its gain register in the transmit link power driver circuit based on the power compensation value, the main controller can first determine the gain step relationship between the digital baseband and its gain register in the transmit link power driver circuit and the power compensation value based on the power compensation value and the target transmit link gain configuration table, and then adjust the gain of the digital baseband and its gain register based on the gain step relationship.

[0115] Schematically, as shown in Figure 8, Figure 8 is a schematic diagram of the gain step relationship of the digital baseband and its gain register in the transmit link power driving circuit provided in an embodiment of the present application; DBB_gain in Figure 8 is the digital baseband and its gain register, Modulator_Gain is the mixer and its gain register, and Driver PA_Gain is the driving power amplifier and its gain register. When DBB_gain, Modulator_Gain, and Driver PA_Gain take different values, their corresponding gain compensation and transmit power adjustment ranges are different. For example, when DBB_gain is 60, Modulator_Gain is 4, and Driver PA_Gain is 0, the gain compensation is -0.1*29, where 0.1 refers to the adjustment step, 29=(89-60) refers to the lower limit of the adjustment, and the gain compensation refers to the power compensation value of the actual transmit power. Under this power compensation value, the adjusted actual transmit power is -3dBm; when DBB_gain is 89, Modulator_Gain is 4, and Driver PA_Gain is 0, the gain compensation is 0. Under this power compensation value, the adjusted actual transmit power is -0.1dBm; and when DBB_gain is 130, Modulator_Gain is 4, and Driver PA_Gain is 0, the gain compensation is 0. When PA_Gain is 0, the gain compensation is +0.1*41, where 41 = (130 - 89) represents the upper limit of adjustment. At this power compensation value, the actual transmit power after adjustment is 4 dBm. In other words, when the actual transmit power is 0 dB, the adjustable error range is -3 to 4 dBm. By analogy, the gain step relationship between the digital baseband and its gain register in the transmit link power driver circuit and the power compensation value can be derived. This gain step relationship can then be used to adjust the gain of the digital baseband and its gain register.

[0116] In one embodiment, as shown in FIG9 , FIG9 is a schematic diagram of a circuit structure for configuring a target transmission link gain configuration table according to an embodiment of the present application; determining a pre-configured target transmission link gain configuration table corresponding to the target transmission power in S410 may include:

[0117] S411: Obtain a pre-configured initial transmission link gain configuration table of each gain driving unit of the transmission link power driving circuit, and multiple target transmission powers obtained after configuring the gains of each gain driving unit of the transmission link power driving circuit according to the initial transmission link gain configuration table.

[0118] S412: After obtaining the gains of each gain driving unit of the transmit link power driving circuit corresponding to each target transmit power in sequence through PC software, configure each gain driving unit of the transmit link power driving circuit according to the obtained gains, and obtain the actual transmit power output by the transmit link power driving circuit after the configured gains through a spectrum analyzer.

[0119] S413: Determine whether the actual transmit power is equal to the corresponding target transmit power.

[0120] S414: If not equal, then after adjusting the initial transmit link gain configuration table according to the deviation between the actual transmit power and the target transmit power, return to executing the steps of sequentially obtaining the gains of each gain driving unit of the transmit link power driving circuit corresponding to each target transmit power through PC software and subsequent steps.

[0121] S415: If equal, obtain the target temperature range corresponding to the target transmit power detected by the temperature sensor, and send the target temperature range corresponding to the target transmit power to the PC software for storage. Until all target transmit powers are calibrated, all target transmit powers and corresponding target temperature ranges, and the gains of each gain driving unit of the transmit link power driving circuit are sorted by the PC software to form a target transmit link gain configuration table.

[0122] In this embodiment, when determining the target transmission link gain configuration table, one can first obtain the initial transmission link gain configuration table for each gain driving unit of the pre-configured transmission link power driving circuit, and multiple target transmission powers obtained by configuring the gains of each gain driving unit of the transmission link power driving circuit according to the initial transmission link gain configuration table. Schematically, as shown in FIG10, FIG10 is a diagram showing the relationship between the initial transmission link gain configuration table and the corresponding target transmission power provided by an embodiment of the present application; FIG10 shows the relationship between the gains of each gain driving unit of the transmission link power driving circuit corresponding to a transmission power between 0 and 27 dBm. FIG9 can be used to quickly determine the gains of each gain driving unit of the transmission link power driving circuit corresponding to each target transmission power. In this way, the present application can configure the target transmission link gain configuration table through the circuit structure diagram shown in FIG9.

[0123] Specifically, the present application can sequentially obtain the gains of each gain driving unit of the transmission link power driving circuit corresponding to each target transmission power through PC software. For each target transmission power, the present application can configure each gain driving unit of the transmission link power driving circuit according to the obtained gain, and obtain the actual transmission power output by the transmission link power driving circuit after the configuration gain through the spectrum analyzer, and then determine whether the actual transmission power is equal to the corresponding target transmission power. If not, the initial transmission link gain configuration table is adjusted according to the deviation between the actual transmission power and the target transmission power, and the gains of each gain driving unit of the transmission link power driving circuit corresponding to each target transmission power are obtained again through PC software. Then, for each target transmission power, the present application can continue to configure each gain driving unit of the transmission link power driving circuit according to the obtained gain, and obtain the actual transmission power output by the transmission link power driving circuit after the configuration gain through the spectrum analyzer, and then determine whether the actual transmission power is equal to the corresponding target transmission power, thereby detecting the actual transmission power at each target transmission power.

[0124] When the actual transmit power is equal to the corresponding target transmit power, the target temperature range corresponding to the target transmit power detected by the temperature sensor can be obtained, and the target temperature range corresponding to the target transmit power can be sent to the PC software for storage. After all target transmit powers are calibrated, all target transmit powers and corresponding target temperature ranges, and the gains of each gain driving unit of the transmit link power driving circuit are sorted out by the PC software to form a target transmit link gain configuration table. As shown in Figure 11, Figure 11 is a structural schematic diagram of the target transmit link gain configuration table provided by an embodiment of the present application; Figure 11 shows the relationship between the gains of each gain driving unit of the transmit link power driving circuit corresponding to the transmit power between 0 and 27dBm and the temperature value at each transmit power. The main controller can determine the gain step relationship between the digital baseband in the transmit link power driving circuit and its gain register and the power compensation value based on the target transmit link gain configuration table.

[0125] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising the element.

[0126] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referenced to each other.

[0127] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An RFID reader / writer system, characterized in that: The system includes a transmission link power driving circuit and a radio frequency power calibration circuit; Wherein, the transmission link power driving circuit includes at least a digital baseband and a gain register thereof, and the radio frequency power calibration circuit includes a main controller and a temperature sensor; The input end of the temperature sensor is connected to the transmission link power driving circuit, and the output end is connected to the input end of the main controller, and is used to detect the real-time onboard temperature of the transmission link power driving circuit and send the real-time onboard temperature to the main controller; The output end of the main controller is connected to the digital baseband and its gain register, and is used to determine whether to adjust the gain of the transmission link power driving circuit according to the received real-time onboard temperature, and when determining to adjust, adjust the gain of the digital baseband and its gain register according to the real-time onboard temperature.

2. The RFID reader-writer system according to claim 1, characterized in that: The process of determining, by the main controller, whether to adjust the gain of the transmission link power driving circuit according to the received real-time onboard temperature includes: The main controller determines a target transmit power of the transmit link power driving circuit and a target temperature range of the target transmit power, and compares the received real-time onboard temperature with the target temperature range; When the main controller determines that the real-time onboard temperature is within the target temperature range, it determines not to adjust the gain of the transmission link power driving circuit; when it determines that the real-time onboard temperature is not within the target temperature range, it determines to adjust the gain of the transmission link power driving circuit.

3. The RFID reader-writer system according to claim 1, characterized in that: The process of the main controller adjusting the gain of the digital baseband and its gain register according to the real-time onboard temperature includes: The main controller determines a power compensation value of the actual transmission power of the transmission link power driving circuit according to the real-time onboard temperature, and adjusts the gain of the digital baseband and its gain register according to the power compensation value.

4. The RFID reader-writer system according to any one of claims 1 to 3, characterized in that: The transmission link power driving circuit also includes a baseband DAC, a mixer and a gain register thereof, a driving power amplifier and a gain register thereof, a filter, a final-stage adjustable gain power amplifier and a directional coupler connected in sequence; The input end of the baseband DAC is connected to the output end of the digital baseband and its gain register.

5. A transmission power control method, applied to a main controller in an RFID reader / writer system according to any one of claims 1 to 4, characterized in that: The method comprises: When transmitting electromagnetic waves, determining a target transmission power of a transmission link power driving circuit, an actual transmission power after configuring the gain of the transmission link power driving circuit according to the target transmission power, and a real-time onboard temperature of the transmission link power driving circuit detected by a temperature sensor when transmitting electromagnetic waves according to the actual transmission power; determining whether the real-time onboard temperature is within a target temperature range of the target transmit power; If the real-time onboard temperature is within the target temperature range, exit the power control link; If the real-time onboard temperature is not within the target temperature range, the power compensation value of the actual transmit power is determined according to the real-time onboard temperature, and after adjusting the gain of the digital baseband and its gain register in the transmit link power driving circuit according to the power compensation value, the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power and subsequent steps are returned to be executed until the power error between the actual transmit power and the target transmit power does not exceed the preset error threshold.

6. The transmission power control method according to claim 5, characterized in that: The determining the actual transmit power after configuring the gain of the transmit link power driving circuit according to the target transmit power includes: Acquire a pre-configured target transmission link gain configuration table corresponding to the target transmission power; After configuring the gain of the transmit link power driving circuit according to the target transmit link gain configuration table, the actual transmit power of the transmit link power driving circuit after the gain is configured is obtained.

7. The transmission power control method according to claim 5, characterized in that: The determining the power compensation value of the actual transmit power according to the real-time onboard temperature and the target temperature range includes: Determine a fitting formula between actual transmit power at different temperatures and radio frequency power at a preset temperature, wherein the fitting formula includes a power compensation value between actual transmit power at different temperatures and radio frequency power at a preset temperature; After comparing the actual transmit power at the real-time onboard temperature with the fitting formula, a power compensation value of the actual transmit power at the real-time onboard temperature is determined.

8. The transmission power control method according to claim 7, characterized in that: The fitting formula for determining the actual transmission power at different temperatures and the radio frequency power at a preset temperature includes: Placing the transmission link power driving circuit in a constant temperature test box, and controlling the radio frequency output and the test box temperature of the constant temperature test box by PC software; The temperature sensor is used to obtain the real-time temperature of the transmission link power driving circuit at the RF output under different test chamber temperatures and the actual transmission power collected by the spectrum analyzer at the real-time temperature; After subtracting the actual transmission power at different test chamber temperatures from the radio frequency power at a preset temperature, a power compensation value between the actual transmission power at different test chamber temperatures and the radio frequency power at a preset temperature is obtained; According to the power compensation value between the actual transmission power at different test chamber temperatures and the radio frequency power at the preset temperature, a fitting formula between the actual transmission power at different temperatures and the radio frequency power at the preset temperature is determined.

9. The transmission power control method according to claim 5, characterized in that: The step of adjusting the gain of the digital baseband and its gain register in the transmission link power driving circuit according to the power compensation value comprises: Determine a pre-configured target transmission link gain configuration table corresponding to the target transmission power, wherein the target transmission link gain configuration table includes a target temperature range corresponding to the target transmission power; Determine, according to the power compensation value and the target transmission link gain configuration table, a gain step relationship between a digital baseband and a gain register in the transmission link power driving circuit and the power compensation value; The gain of the digital baseband and its gain register are adjusted according to the gain step relationship.

10. The transmission power control method according to claim 9, characterized in that: The determining of a pre-configured target transmission link gain configuration table corresponding to the target transmission power includes: Acquire a pre-configured initial transmission link gain configuration table of each gain driving unit of the transmission link power driving circuit, and multiple target transmission powers obtained after configuring the gain of each gain driving unit of the transmission link power driving circuit according to the initial transmission link gain configuration table; After sequentially obtaining the gains of the various gain driving units of the transmission link power driving circuit corresponding to the various target transmission powers through PC software, the various gain driving units of the transmission link power driving circuit are configured according to the obtained gains, and the actual transmission power output by the transmission link power driving circuit after the configured gains is obtained through a spectrum analyzer; Determining whether the actual transmit power is equal to the corresponding target transmit power; If not equal, adjusting the initial transmission link gain configuration table according to the deviation between the actual transmission power and the target transmission power, returning to execute the steps of sequentially obtaining the gains of each gain driving unit of the transmission link power driving circuit corresponding to each target transmission power through PC software and subsequent steps; If they are equal, then the target temperature range corresponding to the target transmit power detected by the temperature sensor is obtained, and the target temperature range corresponding to the target transmit power is sent to the PC software for storage, until all target transmit powers are calibrated, and all target transmit powers and corresponding target temperature ranges, and the gains of each gain driving unit of the transmit link power driving circuit are sorted out by the PC software to form a target transmit link gain configuration table.

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