Power calibration method of airborne receiver based on frequency and attenuation compensation

Abstract

The invention discloses a power calibration method of an airborne receiver based on frequency and attenuation compensation, which comprises the following steps of: S1, constructing a power value calibration table and an attenuation code calibration table, initializing, and then writing the two initialized tables into an address corresponding to an RAM (Random Access Memory) module of the receiver; s2, in the working process, processing a PDWPre message uploaded by a receiver, and specifically comprising the following steps: S21, extracting a local frequency, an intermediate frequency and a voltage amplitude value in the PDWPre message, and calibrating through a power value calibration table to obtain a power value before power compensation; s22, extracting the local frequency in the PDWPre message and an attenuation code controlled by the current microwave, and obtaining a power compensation value through an attenuation code calibration table; and S23, adding the power value obtained in the step S21 and the power compensation value obtained in the step S22 to obtain a final real power value. According to the invention, through automatically compensating nonlinearity and frequency response difference of an internal link of the receiver, a stable power value can be obtained even if a voltage amplitude value fluctuates.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic countermeasure and radar signal processing, and in particular relates to a power calibration method of an airborne receiver based on frequency and attenuation compensation. Background Art

[0002] In modern electronic countermeasures and radar systems, the receiver is an important component, and its performance directly affects the accuracy of signal reception and processing. Especially in complex battlefield environments and under the influence of multiple interference signals, the accurate power measurement of the receiver is crucial. However, due to the differences in the amplitude-frequency characteristics and nonlinearity of the internal link of the receiver, the traditional receiver has a nonlinear relationship between the voltage amplitude and the input power in actual operation. The volatility and instability of this relationship cause the measured voltage amplitude to deviate when the same power value is applied to the input end, making the power value in the power description word (PDW) output by the receiver inaccurate and unstable, causing measurement errors in the system, thereby affecting the functions of other modules.

[0003] At present, the solution to this problem mainly relies on single calibration or manual correction of frequency points. These methods often lack flexibility and accuracy and are difficult to adapt to the power measurement needs in wide frequency bands and dynamic environments. Especially for airborne radar receiving and jamming systems in complex environments, the accuracy and stability of receiver power measurement are even more important. Summary of the invention

[0004] Technical purpose: To solve the above technical problems, the present invention proposes a power calibration method for an airborne receiver based on frequency and attenuation compensation, which provides accurate and stable power measurement results and improves the reliability and anti-interference ability of the system.

[0005] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution: a power calibration method for an airborne receiver based on frequency and attenuation compensation, characterized in that it includes the following steps:

[0006] S1. Construct a power value calibration table and an attenuation code calibration table and initialize them, and then write the two initialized tables into the corresponding addresses of the RAM module of the receiver;

[0007] The fields of the power value calibration table include: local oscillator number, intermediate frequency point number, and power values ​​corresponding to multiple groups of amplitude values; the fields of the attenuation code calibration table include: local oscillator number and attenuation values ​​corresponding to multiple groups of attenuation codes;

[0008] S2. During the working process, the receiver processes the uploaded PDW_Pre message. The specific steps are as follows:

[0009] S21, extracting the local oscillator frequency, intermediate frequency and voltage amplitude value in the PDW_Pre message, and calibrating the power value before power compensation through the power value calibration table;

[0010] S22, extracting the local oscillator frequency in the PDW_Pre message and the attenuation code of the current microwave control, and obtaining the power compensation value through the attenuation code calibration table;

[0011] S23, adding the power value obtained in S21 and the power compensation value obtained in S22 to obtain a final real power value.

[0012] The technical solution of the present invention is further limited to that the fields of the power value calibration table are specifically:

[0013] The value range of the local oscillator number is 0 to 36, and the corresponding relationship with the local oscillator frequency is: the frequency range of the local oscillator frequency is 0 to 18 GHz, with a step of 500 MHz;

[0014] The intermediate frequency point number ranges from 0 to 10, and the corresponding relationship with the intermediate frequency point is: the intermediate frequency point takes the instantaneous width of 1 GHz with the local oscillator frequency as the center, with a step of 100 MHz.

[0015] Furthermore, the initialization process of the power value calibration table is:

[0016] 1.1. Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us;

[0017] S1.2, the signal source frequency is set to the lower sideband of the current frequency band;

[0018] 1.3. Set the signal source power to -80dBm;

[0019] 1.4. According to the PDW_Pre message uploaded by the receiver, the PDW_Pre message refers to the PDW message to be processed, record the average value of PA in 200 PDW_Pre, PA is the voltage amplitude value, and record the power value corresponding to the amplitude value in the corresponding position of the power value calibration table;

[0020] 1.5. Determine whether the power value of the current signal source is less than or equal to 35dBm. If the signal source power is less than or equal to 35dBm, adjust the signal source power plus 1dBm and re-execute step 1.4; if the signal source power is greater than 35dBm, execute step 1.6;

[0021] 1.6. Determine whether the frequency value of the current signal source is less than the upper sideband of the current frequency band. If the signal source frequency is less than the upper sideband of the current frequency band, adjust the signal source frequency plus 100MHz and re-execute step 1.3; if the signal source frequency is not less than the upper sideband of the current frequency band, execute step 1.7;

[0022] 1.7. If the current local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 1.2, otherwise end.

[0023] Furthermore, the fields of the attenuation code calibration table are specifically:

[0024] The value range of the local oscillator number is 0 to 36, and the corresponding relationship with the local oscillator frequency is: the frequency range of the local oscillator frequency is 0 to 18 GHz, with a step of 500 MHz; the value range of the attenuation code is 0 to 127.

[0025] Furthermore, the initialization process of the attenuation code calibration table is:

[0026] 2.1 Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us;

[0027] 2.2. The signal source frequency is set to the center frequency of the current frequency band;

[0028] 2.3. Set the signal source power to -35dBm;

[0029] 2.4. The power attenuation value corresponding to the attenuation code is recorded in the corresponding position of the mapping table. The attenuation code is sent to the microwave by the receiver. The attenuation code corresponds to the actual attenuation value of the microwave, and the corresponding relationship is provided by the microwave.

[0030] 2.5. If the actual attenuation value is greater than 40dBm, execute step 2.6; otherwise, adjust the attenuation code to increase the attenuation value by 1dBm and execute step 2.4 again;

[0031] 2.6. If the local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 2.1, otherwise end.

[0032] Furthermore, the specific method of writing the two initialized tables into the addresses corresponding to the RAM module of the receiver is:

[0033] The power value calibration table address calculation logic is: w_addr_1=spi_data_addr0*256+37*256*spi_data_addr1+spi_data_cnt[8:0], where w_addr_1 represents the address of the power value calibration table in the RAM where the data is written, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, spi_data_addr1 corresponds to the intermediate frequency point number value in the mapping table, and spi_data_cnt represents the data count received by the receiver;

[0034] The calculation logic of the attenuation code calibration table address is: w_addr_2 = spi_data_addr0[6:0]*128+spi_data_cnt[8:0], where w_addr_2 represents the address where the attenuation code calibration table writes data in RAM, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, and spi_data_cnt corresponds to the data count received by SPI.

[0035] Further, in step S21, the specific method of calibrating the power value before power compensation through the power value calibration table is: first convert the local oscillator frequency and intermediate frequency frequency corresponding to the PDW_Pre before calibration into the corresponding local oscillator number and intermediate frequency point number, and then calculate the corresponding power value together with the voltage amplitude value measured in PDW_Pre to calculate the read data address in the RAM. The calculation formula of the address is as follows:

[0036] r_addr=lo_num*256+if_num*37*256+PA[15:8],

[0037] Wherein, r_addr indicates the address of the data read in the RAM, lo_num indicates the local oscillator number corresponding to the current local oscillator frequency, if_num indicates the intermediate frequency point number corresponding to the current intermediate frequency frequency, which is obtained according to the calculation method of the local oscillator number and the intermediate frequency point number mentioned above, and PA indicates the current measured voltage amplitude value, which is directly read from PDW_Pre; the power value read out from the read data address obtained in the above manner will be used as the power value before power compensation.

[0038] Further, in step S22, the specific method of obtaining the power compensation value through the attenuation code calibration table is as follows: when performing table lookup compensation, the current local oscillator frequency is converted into the corresponding local oscillator number and then the read data address of the compensated power value in the RAM is calculated together with the attenuation code of the current microwave control given in the microwave control message. The calculation formula of the address is as follows:

[0039] r_addr=lo_num*128+front_atten,

[0040] In the formula, r_addr represents the address of reading data in RAM, lo_num represents the local oscillator number corresponding to the current local oscillator frequency, which is obtained according to the calculation method of the previous local oscillator number, and front_atten represents the attenuation codeword of the current microwave, which is read from the microwave message; the power compensation value is read out from the read data address obtained in the above manner.

[0041] Beneficial effects:

[0042] The method of the present invention realizes the technology of adaptive calibration. By automatically compensating for the nonlinearity and frequency response difference of the internal link of the receiver, even if the voltage amplitude value fluctuates, a stable power value can be obtained through two table lookup calibration operations, and the power value is equal to the actual input power value, thereby ensuring that the subsequent module has a stable input, and the final frequency measurement result can remain stable and accurate, which is more meaningful for reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flow chart of a power calibration method for an airborne receiver based on frequency and attenuation compensation proposed by the present invention;

[0044] Figure 2 A flowchart of the initialization process of the power value calibration table proposed by the present invention;

[0045] Figure 3 This is a flow chart of the initialization process of the attenuation code calibration table proposed by the present invention. DETAILED DESCRIPTION

[0046] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0047] Embodiment 1

[0048] Specifically, it relates to an adaptive calibration method and device for improving the power measurement accuracy and stability of an airborne receiver, which is suitable for radar signal receiving and jamming systems in complex environments.

[0049] In this embodiment, the corresponding relationship between the voltage amplitude value and the power value under different local oscillator frequencies, intermediate frequencies, and attenuation codes is measured in advance and recorded in two tables, Table 1 is the power value calibration table, and Table 2 is the attenuation code calibration table.

[0050] The content of the power value calibration table is the correspondence between the voltage amplitude value and the power value under different local oscillator frequencies and intermediate frequencies. Each intermediate frequency under each local oscillator will correspond to an independent table. Each table will record the power values ​​corresponding to different amplitude values ​​under the current local oscillator and intermediate frequency. The mapping table structure is shown in Table 1:

[0051] Serial number Field Name Range Description unit default value Length (bits) illustrate 0 Start Frame / / 32 / 1 Message Type / / 32 / 2 Message length / / 32 / 3 LO Number 0～36 / / 32 / 4 IF frequency number 0～10 / / 32 / 5 The power value corresponding to the amplitude value 0 0.25dBm / 32 6 The power value corresponding to the amplitude value 1 / / 32 … … … / / /

[0052] Table 1

[0053] The power value calibration table converts the voltage amplitude value into the power value and performs amplitude calibration. The main information contained in the power value calibration table message includes the local oscillator frequency, the intermediate frequency, and the power value corresponding to the amplitude value.

[0054] In the message, the value range of the local oscillator number is 0 to 36, and the corresponding relationship with the local oscillator frequency is: the frequency range of the local oscillator frequency is 0 to 18 GHz, with a step of 500 MHz. In the message, the value range of the intermediate frequency point number is 0 to 10, and the corresponding relationship with the intermediate frequency point is: the intermediate frequency point takes the local oscillator frequency as the center and takes an instantaneous width of 1 GHz, with a step of 100 MHz. For example, when the local oscillator frequency is 2 GHz and the frequency is 2.3 GHz, the corresponding local oscillator number is 4 and the intermediate frequency point number is 8.

[0055] During the table generation process, each time the power is adjusted, a set of amplitude values ​​and the corresponding power values ​​will be generated and then recorded in the table. If the content in the table needs to be updated, the table generation process is re-executed. The message also contains two sets of power value information corresponding to the amplitude values ​​0 to 255. The first 0 to 255 amplitude values ​​in the table correspond to the 8th to 15th bit data of the voltage amplitude value in the PDW before calibration, and the second 0 to 255 amplitude values ​​correspond to the 4th to 11th bit data of the voltage amplitude value in the PDW before calibration.

[0056] The process of generating the power value calibration table is as follows:

[0057] 1.1. Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us;

[0058] 1.2. The signal source frequency is set to the lower sideband of the current frequency band;

[0059] 1.3. Set the signal source power to -80dbm;

[0060] 1.4. According to the PDW_Pre message uploaded by the receiver, the PDW_Pre message refers to the PDW message to be processed, record the average value of PA in 200 PDW_Pre, PA is the voltage amplitude value, and record the power value corresponding to the amplitude value in the corresponding position of the power value calibration table;

[0061] 1.5. Determine whether the power value of the current signal source is less than or equal to 35dBm. If the signal source power is less than or equal to 35dBm, adjust the signal source power plus 1dBm and re-execute step 1.4; if the signal source power is greater than 35dBm, execute step 1.6;

[0062] 1.6. Determine whether the frequency value of the current signal source is less than the upper sideband of the current frequency band. If the signal source frequency is less than the upper sideband of the current frequency band, adjust the signal source frequency plus 100MHz and re-execute step 1.3; if the signal source frequency is not less than the upper sideband of the current frequency band, execute step 1.7;

[0063] 1.7. If the current local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 1.2, otherwise end.

[0064] The content of the attenuation code calibration table is the correspondence between the attenuation code and the power compensation value under different local oscillator frequencies. Each intermediate frequency under each local oscillator will correspond to an independent table. Each table will record the power value corresponding to the different attenuation under the current local oscillator. If the content of the table needs to be updated, the table creation process is re-executed. The logic is similar to the power attenuation table. The mapping table structure is shown in Table 2:

[0065] Serial number Field Name Range Description unit default value Length (bits) illustrate 0 Start frame flag / / 32 / 1 Message Type / / 32 / 2 Message length / / 32 / 3 LO Number 0～36 / / 32 / 4 Attenuation value corresponding to attenuation code 0 0.25dBm / 32 / 5 Attenuation value corresponding to attenuation code 1 / / 32 … … … … … … …

[0066] Table 2

[0067] The attenuation code calibration table realizes compensation for the power value after microwave attenuation, and finally obtains the real power value. The main information contained in the attenuation code calibration table message includes the local oscillator number and the power value corresponding to the attenuation code. The method for generating the local oscillator number is the same as that in the power value calibration table, and the value range is also 0 to 36, corresponding to 0 to 18 GHz. The message also contains the real power attenuation value corresponding to the attenuation code with different values, and the value range of the attenuation code is 0 to 127.

[0068] The process of generating the attenuation code calibration table is as follows:

[0069] 2.1 Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us;

[0070] 2.2. The signal source frequency is set to the center frequency of the current frequency band;

[0071] 2.3. Set the signal source power to -35dBm;

[0072] 2.4. The power attenuation value corresponding to the attenuation code is recorded in the corresponding position of the mapping table. The attenuation code is sent to the microwave by the receiver. The attenuation code corresponds to the actual attenuation value of the microwave, and the corresponding relationship is provided by the microwave.

[0073] 2.5. If the actual attenuation value is greater than 40dB, execute step 2.6; otherwise, adjust the attenuation code to increase the attenuation value by 1dB and execute step 2.4 again;

[0074] 2.6. If the local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 2.1, otherwise end.

[0075] The above two tables will be sent to the receiver in the form of messages, and the receiver will write the data into the corresponding address of the receiver's RAM module according to the designed address calculation logic.

[0076] The calculation logic of the power value calibration table address is: the message is transmitted to the receiver through SPI, and the data is saved in the RAM of the receiver that stores the power value calibration table. The address where the data is written is generated by three parameters: the local oscillator number, the intermediate frequency point number, and the data count. The formula is as follows:

[0077] w_addr_1=spi_data_addr0*256+37*256*spi_data_addr1+spi_data_cnt[8:0]

[0078] In the formula, w_addr_1 represents the address where the power value calibration table writes data in RAM, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, spi_data_addr1 corresponds to the intermediate frequency point number value in the mapping table, and spi_data_cnt represents the data count received by SPI. These parameters will be sent in the form of messages.

[0079] The calculation logic of the attenuation code calibration table address is: the message is transmitted to the receiver via SPI, and the data is saved in the RAM of the receiver that stores the attenuation value calibration table. The address where the data is written is generated by two parameters: the local oscillator number and the data count. The formula is as follows:

[0080] w_addr_2=spi_data_addr0[6:0]*128+spi_data_cnt[8:0];

[0081] Where w_addr_2 represents the address where the attenuation code calibration table writes data in RAM, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, and spi_data_cnt corresponds to the data count received by SPI. These parameters will be sent in the form of messages.

[0082] When the receiver is working, it will perform two table lookup operations based on the local oscillator frequency, intermediate frequency, attenuation code and other information of the current signal, read the corresponding data from the correct address, and finally obtain the calibrated power value through calculation, thereby ensuring that the final output is the real power value.

[0083] During the working process, the PDW_Pre message uploaded by the receiver is processed. The specific steps are as follows:

[0084] Step 1: Use the power value calibration table to calibrate the power value before power compensation.

[0085] When performing table calibration, first convert the local oscillator frequency and intermediate frequency corresponding to PDW_Pre before calibration into the corresponding local oscillator number and intermediate frequency point number, and then calculate the corresponding power value read data address in RAM together with the voltage amplitude value measured in PDW_Pre. The calculation formula of this address is as follows:

[0086] r_addr=lo_num*256+if_num*37*256+PA[15:8],

[0087] Where r_addr represents the address of the data read in RAM, lo_num represents the local oscillator number corresponding to the current local oscillator frequency, if_num represents the intermediate frequency point number corresponding to the current intermediate frequency frequency, which is obtained according to the calculation method of the local oscillator number and the intermediate frequency point number mentioned above, and PA represents the current measured voltage amplitude value, which is directly read from PDW_Pre.

[0088] The power value read out from the read data address obtained in the above manner will be used as the power value before power compensation. The power value needs to be compensated for the attenuation of the power value in the next step to obtain the real power value.

[0089] Step 2: Get the power compensation value through the attenuation code calibration table.

[0090] When performing table lookup compensation, the current local oscillator frequency is converted into the corresponding local oscillator number, and then the read data address of the compensated power value in RAM is calculated together with the attenuation code of the current microwave control given in the microwave control message. The calculation formula of the address is as follows:

[0091] r_addr=lo_num*128+front_atten,

[0092] Where r_addr represents the address of the data read in the RAM, lo_num represents the local oscillator number corresponding to the current local oscillator frequency, which is obtained according to the calculation method of the previous local oscillator number, and front_atten represents the attenuation codeword of the current microwave, which is read from the microwave message.

[0093] The power compensation value is read out by the read data address obtained in the above manner.

[0094] In the third step, the power value obtained in the first step and the power compensation value obtained in the second step are added together to obtain the final real power value.

[0095] Through the above two table lookups, a stable power value is obtained, and it is equal to the actual input power value, ensuring that the subsequent module will have a stable input and the final frequency measurement result can remain stable and accurate.

[0096] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A power calibration method for an airborne receiver based on frequency and attenuation compensation, characterized in that: The following steps are involved: S1, construct a power value calibration table and an attenuation code calibration table and initialize them, and then write the two initialized tables into the corresponding addresses of the RAM module of the receiver; The fields of the power value calibration table include: local oscillator number, intermediate frequency point number, and power values ​​corresponding to multiple groups of amplitude values; the fields of the attenuation code calibration table include: local oscillator number and attenuation values ​​corresponding to multiple groups of attenuation codes; S2. During the working process, the receiver processes the uploaded PDW_Pre message. The specific steps are as follows: S21, extracting the local oscillator frequency, intermediate frequency and voltage amplitude value in the PDW_Pre message, and calibrating the power value before power compensation through the power value calibration table; S22, extracting the local oscillator frequency in the PDW_Pre message and the attenuation code of the current microwave control, and obtaining the power compensation value through the attenuation code calibration table; S23, adding the power value obtained in S21 and the power compensation value obtained in S22 to obtain a final real power value.

2. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 1, characterized in that: The fields of the power value calibration table are specifically: The value range of the local oscillator number is 0 to 36, and the corresponding relationship with the local oscillator frequency is: the frequency range of the local oscillator frequency is 0 to 18 GHz, with a step of 500 MHz; The intermediate frequency point number ranges from 0 to 10, and the corresponding relationship with the intermediate frequency point is: the intermediate frequency point takes the instantaneous width of 1 GHz with the local oscillator frequency as the center, with a step of 100 MHz.

3. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 2, characterized in that: The initialization process of the power value calibration table is: 1.

1. Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us; S1.2, the signal source frequency is set to the lower sideband of the current frequency band; 1.

3. Set the signal source power to -80dBm; 1.

4. According to the PDW_Pre message uploaded by the receiver, the PDW_Pre message refers to the PDW message to be processed, record the average value of PA in 200 PDW_Pre, PA is the voltage amplitude value, and record the power value corresponding to the amplitude value in the corresponding position of the power value calibration table; 1.

5. Determine whether the power value of the current signal source is less than or equal to 35dBm. If the signal source power is less than or equal to 35dBm, adjust the signal source power by 1dBm and re-execute step 1.4; If the signal source power is greater than 35dBm, go to step 1.6; 1.

6. Determine whether the frequency value of the current signal source is less than the upper sideband of the current frequency band. If the signal source frequency is less than the upper sideband of the current frequency band, adjust the signal source frequency plus 100MHz and re-execute step 1.3; If the signal source frequency is not less than the upper sideband of the current frequency band, execute step 1.7; 1.

7. If the current local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 1.2, otherwise end.

4. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 1, characterized in that: The fields of the attenuation code calibration table are specifically: The value range of the local oscillator number is 0 to 36, and the corresponding relationship with the local oscillator frequency is: the frequency range of the local oscillator frequency is 0 to 18 GHz, with a step of 500 MHz; the value range of the attenuation code is 0 to 127.

5. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 4, characterized in that: The initialization process of the attenuation code calibration table is: 2.1 Switch the receiver state to calibration mode, switch the local oscillator point to the first local oscillator point, set the attenuation code to 0, the signal source pulse width to 2us, and the repetition rate to 4us; 2.

2. The signal source frequency is set to the center frequency of the current frequency band; 2.

3. Set the signal source power to -35dBm; 2.

4. The power attenuation value corresponding to the attenuation code is recorded in the corresponding position of the mapping table. The attenuation code is sent to the microwave by the receiver. The attenuation code corresponds to the actual attenuation value of the microwave, and the corresponding relationship is provided by the microwave. 2.

5. If the actual attenuation value is greater than 40dBm, execute step 2.6; otherwise, adjust the attenuation code to increase the attenuation value by 1dBm and execute step 2.4 again; 2.

6. If the local oscillator is not the last local oscillator, switch to the next local oscillator and execute step 2.1, otherwise end.

6. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 1, characterized in that: The specific method of writing the two initialized tables into the addresses corresponding to the RAM module of the receiver is: The power value calibration table address calculation logic is: w_addr_1=spi_data_addr0*256+37*256*spi_data_addr1+spi_data_cnt[8:0], where w_addr_1 represents the address of the power value calibration table in the RAM where the data is written, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, spi_data_addr1 corresponds to the intermediate frequency point number value in the mapping table, and spi_data_cnt represents the data count received by the receiver; The calculation logic of the attenuation code calibration table address is: w_addr_2 = spi_data_addr0[6:0]*128+spi_data_cnt[8:0], where w_addr_2 represents the address where the attenuation code calibration table writes data in RAM, spi_data_addr0 corresponds to the local oscillator number value in the mapping table, and spi_data_cnt corresponds to the data count received by SPI.

7. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 6, characterized in that: In step S21, the specific method of calibrating the power value before power compensation through the power value calibration table is: first convert the local oscillator frequency and intermediate frequency frequency corresponding to the PDW_Pre before calibration into the corresponding local oscillator number and intermediate frequency point number, and then calculate the corresponding power value read data address in RAM together with the voltage amplitude value measured in PDW_Pre. The calculation formula of the address is as follows: r_addr=lo_num*256+if_num*37*256+PA[15:8], Where r_addr indicates the address of the data read in RAM, lo_num indicates the local oscillator number corresponding to the current local oscillator frequency, if_num indicates the intermediate frequency point number corresponding to the current intermediate frequency frequency, which is obtained according to the calculation method of the local oscillator number and the intermediate frequency point number mentioned above, and PA indicates the current measured voltage amplitude value, which is directly read from PDW_Pre; The power value read out from the read data address obtained in the above manner will be used as the power value before power compensation.

8. The power calibration method of an airborne receiver based on frequency and attenuation compensation according to claim 6, characterized in that: In step S22, the specific method of obtaining the power compensation value through the attenuation code calibration table is as follows: when performing table lookup compensation, the current local oscillator frequency is converted into the corresponding local oscillator number and then the read data address of the compensated power value in the RAM is calculated together with the attenuation code of the current microwave control given in the microwave control message. The calculation formula of the address is as follows: r_addr=lo_num*128+front_atten, Where r_addr indicates the address of the data read in the RAM, lo_num indicates the local oscillator number corresponding to the current local oscillator frequency, which is obtained according to the calculation method of the previous local oscillator number, and front_atten indicates the attenuation codeword of the current microwave, which is read from the microwave message; The power compensation value is read out by the read data address obtained in the above manner.

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