A method for calculating phase difference of multi-channel receiving front end in millimeter wave frequency band

Abstract

The present invention discloses a method for calculating the phase difference of a multi-channel receiving front end in a millimeter wave frequency band, and relates to the field of measurement and control. The present invention first selects N frequency values ​​in the working frequency band of the multi-channel receiving front end in the millimeter wave frequency band, and for the nth frequency value, sequentially measures the phase difference of a single pulse modulator, the phase difference of an azimuth channel, and the phase difference of an elevation channel, and obtains n total phase differences. According to the n total phase differences and the least square method, a linear function corresponding to azimuth and elevation is obtained. When a phase difference occurs in the multi-channel receiving front end in the millimeter wave frequency band, the phase difference calculation is performed according to the linear function to complete the phase difference calculation of the multi-channel receiving front end in the millimeter wave frequency band. The measurement and calculation of the present invention have the characteristics of high stability and high precision, and can be widely used in the realization of system measurement technology with high tracking sensitivity.

Description

Technical Field

[0001] The present invention relates to the field of measurement and control, and in particular to a method for calculating phase difference of a multi-channel receiving front end in a millimeter wave frequency band. Background Art

[0002] With the in-depth development of aerospace technology, the tracking and measurement of aerospace vehicles has entered a new stage. According to the transmission line theory, a change of a quarter wavelength will reverse the electrical characteristics of the device, and a small change in length will cause a huge change in the phase of the system, which puts forward extremely high channel phase consistency requirements on the receiving front end of the tracking system.

[0003] Phase is one of the important indicators of radio technology and has been widely used in the field of measurement and control. The phase characteristics of the measurement and control network are an important part of determining the transmission characteristics of the network. For example, in the phase navigation system, the distance and direction are measured to determine the location of an aircraft or ship; for example, two receivers are installed on the ground, the distance between the receivers is known, and the receivers simultaneously receive signals sent back from the satellite. The position of the satellite can be determined through phase measurement calculation. In the millimeter wave frequency band, the wavelength is only a dozen millimeters, and the traditional method of calculating the phase difference has poor accuracy and is difficult to meet the requirements of the phase consistency of the receiving front-end channel, affecting the tracking sensitivity of the system. Summary of the invention

[0004] In view of this, the present invention proposes a method for calculating the phase difference of a multi-channel receiving front end in the millimeter wave frequency band. The measurement and calculation of the method have the characteristics of high stability and high precision, and can be widely used in the realization of system measurement technology with high tracking sensitivity.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for calculating phase difference of a multi-channel receiving front end in a millimeter wave frequency band, comprising the following steps;

[0007] Step 1, selecting N frequency values ​​in the working frequency band of the millimeter wave frequency band multi-channel receiving front end, wherein the N frequency values ​​evenly divide the working frequency band;

[0008] Step 2, for the nth frequency value, n = 1, 2, 3, ..., N, measure the phase difference of the single pulse modulator corresponding to the current frequency value by a vector network analyzer:

[0009] The phase of the sum signal input port of the single pulse modulator is used as the reference for zero calibration, and the difference between the phase of the azimuth difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port azimuth difference The difference between the phase of the pitch difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port pitch difference

[0010] Step 3: Connect the test cable a , l b To perform zero calibration, cable l a , l b Connect one end of the cable to the Ain port and Bin port of the vector network analyzer respectively. a , l b The other end of is connected to the first input port and the second input port of the frequency splitter respectively, and the output port of the frequency splitter is connected to the PORT1 port of the vector network analyzer. The second input port of the frequency splitter is used as a reference for zero calibration. For the nth frequency value, the phase difference between the first input port and the second input port of the frequency splitter is measured and recorded as

[0011] Step 4: Use the beacon to send single-frequency signals of N frequency values ​​in sequence, adjust the antenna pitch of the millimeter wave band multi-channel receiving front end to align with the beacon, and align the antenna azimuth to the left of the beacon. Single frequency signal wavelength, and right deviation The azimuth phase difference is measured at each wavelength of the single-frequency signal: a , l b One end connected to the first input port and the second input port of the frequency splitter is disconnected, and is respectively connected to the azimuth channel low noise amplifier output port and the sum channel low noise amplifier output port of the millimeter wave frequency band multi-channel receiving front end, and the difference between the azimuth channel phase and the sum channel phase of the millimeter wave frequency band multi-channel receiving front end is recorded as the channel azimuth difference. Among the N groups of channel azimuth differences corresponding to the left deviation and the N groups of channel azimuth differences corresponding to the right deviation, a more linear N group of channel azimuth differences is selected and recorded as

[0012] Step 5: Use the beacon to send single-frequency signals of N frequency values ​​in sequence, adjust the antenna azimuth of the millimeter wave band multi-channel receiving front end to align with the beacon, and adjust the antenna pitch to align with the upper deviation of the beacon. Single frequency signal wavelength, and down-bias The azimuth phase difference is measured at each wavelength of the single-frequency signal: a The azimuth channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end is disconnected and connected to the elevation channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end. The difference between the measured elevation channel phase and the sum channel phase of the millimeter wave band multi-channel receiving front end is recorded as the channel pitch difference. Among the N groups of channel pitch differences corresponding to the upper deviation and the N groups of channel pitch differences corresponding to the lower deviation, the more linear N groups of channel pitch differences are selected and recorded as

[0013] Step 6: For the nth frequency value, the total azimuth phase difference of the multi-channel receiving front end of the corresponding millimeter wave frequency band is recorded as

[0014]

[0015] The corresponding total elevation phase difference of the multi-channel receiving front end in the millimeter wave frequency band is recorded as

[0016]

[0017] Step 7, subtract the adjacent data of the N groups of azimuth total phase differences, calculate the average of the N-1 groups of differences, and record it as k1; subtract the adjacent data of the N groups of elevation total phase differences, calculate the average of the N-1 groups of differences, and record it as k2;

[0018] make

[0019] Step 8: Construct a linear function corresponding to the total azimuth phase difference of the multi-channel receiving front end in the millimeter wave band:

[0020]

[0021] Where f represents the current operating frequency of the millimeter wave band multi-channel receiving front end, f 1 represents the frequency value corresponding to n=1, Δf represents the frequency difference between two adjacent frequency values ​​in N frequency values, x f It represents the total phase difference of the azimuth corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band;

[0022] Construct a linear function corresponding to the total phase difference of the multi-channel receiving front end in the millimeter wave band:

[0023]

[0024] y f It represents the total elevation phase difference corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band;

[0025] When a phase difference occurs in the millimeter wave frequency band multi-channel receiving front end, the phase difference calculation is performed according to the corresponding linear function to complete the phase difference calculation of the millimeter wave frequency band multi-channel receiving front end.

[0026] Due to the adoption of the above technical solution, the beneficial effects of the present invention compared with the prior art are:

[0027] 1. The present invention tests the phase difference value of each frequency point of multiple channels through a novel method, and then uses the least squares estimation method to sort and calculate the test data, and finally obtains a more accurate phase difference value, which can be provided to the system for direct use.

[0028] 2. The measurement and calculation of the present invention have the characteristics of high stability and high precision, and can be widely used in the realization of system measurement technology with high tracking sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of a millimeter wave frequency band multi-channel receiving front end in an embodiment of the present invention.

[0030] Figure 2 Schematic diagram of testing the phase difference of the test cable in an embodiment of the present invention.

[0031] Figure 3 Schematic diagram of testing the channel phase difference in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0033] A method for calculating phase difference of a multi-channel receiving front end in a millimeter wave frequency band, comprising the following steps;

[0034] Step 1, selecting N frequency values ​​in the working frequency band of the millimeter wave frequency band multi-channel receiving front end, wherein the N frequency values ​​evenly divide the working frequency band;

[0035] Specifically, Figure 1 As shown, the millimeter wave frequency band multi-channel receiving front end includes an antenna sum difference network, an azimuth channel, an elevation channel, a sum channel and a single pulse modulator; each channel includes a pre-selection filter and a low noise amplifier;

[0036] The antenna sum-difference network shown outputs an azimuth difference signal to a pre-selection filter in an azimuth channel, the pre-selection filter is connected to a low noise amplifier, and the low noise amplifier is connected to an azimuth difference signal input port of a single pulse modulator;

[0037] The antenna sum and difference network outputs the pitch difference signal to the pre-selection filter in the pitch channel, the pre-selection filter is connected to the low noise amplifier, and the low noise amplifier is connected to the pitch difference signal input port of the single pulse modulator;

[0038] The antenna sum-difference network outputs a sum signal to a pre-selection filter in a sum channel, the pre-selection filter is connected to a low noise amplifier, and the low noise amplifier is connected to a sum signal input port of a single pulse modulator;

[0039] The single pulse modulator modulates according to the 1KHZ (90) RS422 signal and the 1KHZ (0) RS422 signal; +12v is the power input;

[0040] Step 2, for the nth frequency value, n = 1, 2, 3, ..., N, measure the phase difference of the single pulse modulator corresponding to the current frequency value by a vector network analyzer:

[0041] The phase of the sum signal input port of the single pulse modulator is used as the reference for zero calibration, and the difference between the phase of the azimuth difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port azimuth difference The difference between the phase of the pitch difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port pitch difference

[0042] Specifically, Figure 1 As shown, B1 is the azimuth difference signal input port, B2 is the pitch difference signal input port, B3 is the sum signal input port, and C3 is the signal output port of the single pulse modulator;

[0043] Step 3, such as Figure 2 As shown, the test cable l a , l b To perform zero calibration, cable l a , l b Connect one end of the cable to the Ain port and Bin port of the vector network analyzer respectively. a , l b The other end of is connected to the first input port and the second input port of the frequency splitter respectively, and the output port of the frequency splitter is connected to the PORT1 port of the vector network analyzer. The second input port of the frequency splitter is used as a reference for zero calibration. For the nth frequency value, the phase difference between the first input port and the second input port of the frequency splitter is measured and recorded as

[0044] Step 4, such as Figure 3 As shown, a beacon is used to send single-frequency signals of N frequency values ​​in sequence, and the antenna pitch of the millimeter wave band multi-channel receiving front end is adjusted to align with the beacon, and the antenna azimuth is aligned to the left of the beacon. Single frequency signal wavelength, and right deviation The azimuth phase difference is measured at each wavelength of the single-frequency signal: a , l b One end connected to the first input port and the second input port of the frequency splitter is disconnected, and is respectively connected to the azimuth channel low noise amplifier output port and the sum channel low noise amplifier output port of the millimeter wave frequency band multi-channel receiving front end, and the difference between the azimuth channel phase and the sum channel phase of the millimeter wave frequency band multi-channel receiving front end is recorded as the channel azimuth difference. Among the N groups of channel azimuth differences corresponding to the left deviation and the N groups of channel azimuth differences corresponding to the right deviation, a more linear N group of channel azimuth differences is selected and recorded as

[0045] Step 5, such as Figure 3 As shown, a beacon is used to send single-frequency signals of N frequency values ​​in sequence, and the antenna azimuth of the millimeter wave band multi-channel receiving front end is adjusted to align with the beacon, and the antenna pitch is aligned with the upper deviation of the beacon. Single frequency signal wavelength, and down-bias The azimuth phase difference is measured at each wavelength of the single-frequency signal: a The azimuth channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end is disconnected and connected to the elevation channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end. The difference between the measured elevation channel phase and the sum channel phase of the millimeter wave band multi-channel receiving front end is recorded as the channel pitch difference. Among the N groups of channel pitch differences corresponding to the upper deviation and the N groups of channel pitch differences corresponding to the lower deviation, the more linear N groups of channel pitch differences are selected and recorded as

[0046] Specifically, Figure 3 A1 is the low noise amplifier output port of the azimuth channel, A2 is the low noise amplifier output port of the elevation channel, and A3 is the low noise amplifier output port of the sum channel.

[0047] Step 6: For the nth frequency value, the total azimuth phase difference of the multi-channel receiving front end of the corresponding millimeter wave frequency band is recorded as

[0048]

[0049] The corresponding total elevation phase difference of the multi-channel receiving front end in the millimeter wave frequency band is recorded as

[0050]

[0051] Step 7, subtract the adjacent data of the N groups of azimuth total phase differences, calculate the average of the N-1 groups of differences, and record it as k1; subtract the adjacent data of the N groups of elevation total phase differences, calculate the average of the N-1 groups of differences, and record it as k2;

[0052] make

[0053] Step 8: Construct a linear function corresponding to the total azimuth phase difference of the multi-channel receiving front end in the millimeter wave band:

[0054]

[0055] Where f represents the current operating frequency of the millimeter wave band multi-channel receiving front end, f 1 represents the frequency value corresponding to n=1, Δf represents the frequency difference between two adjacent frequency values ​​in N frequency values, xf It represents the total phase difference of the azimuth corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band;

[0056] Construct a linear function corresponding to the total phase difference of the multi-channel receiving front end in the millimeter wave band:

[0057]

[0058] y f It represents the total elevation phase difference corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band;

[0059] When a phase difference occurs in the millimeter wave frequency band multi-channel receiving front end, the phase difference calculation is performed according to the corresponding linear function to complete the phase difference calculation of the millimeter wave frequency band multi-channel receiving front end.

[0060] In summary, the present invention tests the phase difference values ​​of each frequency point of multiple channels through a novel method, and then uses the least squares estimation method to organize and calculate the test data, and finally obtains a more accurate phase difference value, which can be provided to the system for direct use; and the measurement and calculation have the characteristics of high stability and high precision, and can be widely used in the realization of system measurement technology with high tracking sensitivity.

[0061] Those skilled in the art will appreciate that the embodiments described are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to the embodiments described. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for calculating phase difference of a multi-channel receiving front end in a millimeter wave frequency band, characterized in that: The steps include: Step 1, selecting N frequency values ​​in the working frequency band of the millimeter wave frequency band multi-channel receiving front end, wherein the N frequency values ​​evenly divide the working frequency band; Step 2, for the nth frequency value, n = 1, 2, 3, ..., N, measure the phase difference of the single pulse modulator corresponding to the current frequency value by a vector network analyzer: The phase of the sum signal input port of the single pulse modulator is used as the reference for zero calibration, and the difference between the phase of the azimuth difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port azimuth difference The difference between the phase of the pitch difference signal input port of the single pulse modulator and the phase of the sum signal input port is recorded as the port pitch difference Step 3: Connect the test cable a , l b To perform zero calibration, cable l a , l b Connect one end of the cable to the Ain port and Bin port of the vector network analyzer respectively. a , l b The other end of is connected to the first input port and the second input port of the frequency splitter respectively, and the output port of the frequency splitter is connected to the PORT1 port of the vector network analyzer. The second input port of the frequency splitter is used as a reference for zero calibration. For the nth frequency value, the phase difference between the first input port and the second input port of the frequency splitter is measured and recorded as Step 4: Use the beacon to send single-frequency signals of N frequency values ​​in sequence, adjust the antenna pitch of the millimeter wave band multi-channel receiving front end to align with the beacon, and align the antenna azimuth to the left of the beacon. Single frequency signal wavelength, and right deviation The azimuth phase difference is measured at each wavelength of the single-frequency signal: a , l b One end connected to the first input port and the second input port of the frequency splitter is disconnected, and is respectively connected to the azimuth channel low noise amplifier output port and the sum channel low noise amplifier output port of the millimeter wave frequency band multi-channel receiving front end, and the difference between the azimuth channel phase and the sum channel phase of the millimeter wave frequency band multi-channel receiving front end is recorded as the channel azimuth difference. Among the N groups of channel azimuth differences corresponding to the left deviation and the N groups of channel azimuth differences corresponding to the right deviation, a more linear N group of channel azimuth differences is selected and recorded as Step 5: Use the beacon to send single-frequency signals of N frequency values ​​in sequence, adjust the antenna azimuth of the millimeter wave band multi-channel receiving front end to align with the beacon, and adjust the antenna pitch to align with the upper deviation of the beacon. Single frequency signal wavelength, and down-bias The azimuth phase difference is measured at each wavelength of the single-frequency signal: a The azimuth channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end is disconnected and connected to the elevation channel low noise amplifier output port of the millimeter wave band multi-channel receiving front end. The difference between the measured elevation channel phase and the sum channel phase of the millimeter wave band multi-channel receiving front end is recorded as the channel pitch difference. Among the N groups of channel pitch differences corresponding to the upper deviation and the N groups of channel pitch differences corresponding to the lower deviation, the more linear N groups of channel pitch differences are selected and recorded as Step 6: For the nth frequency value, the total azimuth phase difference of the multi-channel receiving front end of the corresponding millimeter wave frequency band is recorded as The corresponding total elevation phase difference of the multi-channel receiving front end in the millimeter wave frequency band is recorded as Step 7, subtract the adjacent data of the N groups of azimuth total phase differences, calculate the average of the N-1 groups of differences, and record it as k1; subtract the adjacent data of the N groups of elevation total phase differences, calculate the average of the N-1 groups of differences, and record it as k2; make Step 8: Construct a linear function corresponding to the total azimuth phase difference of the multi-channel receiving front end in the millimeter wave band: Where f represents the current operating frequency of the millimeter wave band multi-channel receiving front end, f 1 represents the frequency value corresponding to n=1, Δf represents the frequency difference between two adjacent frequency values ​​in N frequency values, x f It represents the total phase difference of the azimuth corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band; Construct a linear function corresponding to the total elevation phase difference of the multi-channel receiving front end in the millimeter wave band: y f It represents the total elevation phase difference corresponding to the frequency f of the multi-channel receiving front end in the millimeter wave band; When a phase difference occurs in the millimeter wave frequency band multi-channel receiving front end, the phase difference calculation is performed according to the corresponding linear function to complete the phase difference calculation of the millimeter wave frequency band multi-channel receiving front end.

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