Radar multi-channel large-bandwidth rapid amplitude-phase calibration method

Abstract

The invention discloses a radar multi-channel large-bandwidth rapid amplitude-phase calibration method, which comprises the following steps of: connecting i channels of a radar feed network, i = 1, 2... N, and each channel comprises an amplitude-phase regulation and control formed by connecting a voltage-controlled phase shifter and a voltage-controlled attenuator in series, a vector network analyzer is used for outputting different frequency signals to amplitude-phase regulation and control and receiving the frequency signals subjected to amplitude-phase regulation and control to calibrate each channel, a filling table is made, and an upper computer connects the vector network analyzer to i channels through a change-over switch. Then, an all-state table is generated through ground state calculation and all-state calculation, compared with the method that data are collected one by one for all states, the efficiency is remarkably improved, and the efficiency of a multi-channel system is improved more obviously; compared with a manual calibration method and a traditional calibration method, time is saved, and the method is particularly obvious when the number of channels is large.

Description

Technical Field

[0001] The invention relates to a fast amplitude and phase calibration method for radar multi-channel and large bandwidth. Background Art

[0002] In the multi-channel system of radar feed network, ensuring the signal consistency between channels is the key to achieve accurate beamforming and signal synthesis. However, hardware differences, aging and environmental factors often lead to inconsistency of amplitude and phase between channels, which greatly affects the overall performance of the system. The existing multi-channel amplitude and phase calibration technology mainly includes two methods: manual calibration and traversal calibration:

[0003] Manual calibration: The calibrator constantly modifies the attenuator and phase shifter settings, and records the S21 insertion loss value, S12 phase value, and attenuator and phase shifter settings of the vector network analyzer, and then forms a record table. The disadvantage of this method is that the workload of manual repetitive operations is very large, the efficiency is low, and the accuracy of calibration is often not guaranteed.

[0004] Traversal calibration: Perform comprehensive traversal calibration for different frequencies, amplitudes, and phases. In theory, this method can ensure that the amplitude and phase of a multi-channel system achieve optimal accuracy, but when the number of channels, amplitudes, and phases is large, this method will make the calibration process extremely time-consuming and affect product production efficiency.

[0005] Therefore, the traditional calibration method is no longer applicable to multi-channel and large bandwidth systems. Under the premise of ensuring amplitude and phase accuracy, how to quickly achieve amplitude and phase calibration of multi-channel systems needs to be solved urgently. Summary of the invention

[0006] In view of the above problems, the purpose of the present invention is to provide a multi-channel large-bandwidth fast amplitude and phase calibration method, which compensates for the characteristics of multiple channels through a calibration algorithm, thereby reducing the amplitude and phase differences between the channels to an acceptable range, thereby improving the efficiency of multi-channel amplitude and phase calibration.

[0007] In order to achieve the above-mentioned purpose, the scheme of the present invention is: a radar multi-channel large bandwidth fast amplitude and phase calibration method, including i channels connected to the radar feed network, i=1,2...N, each channel contains an amplitude and phase control composed of a voltage-controlled phase shifter and a voltage-controlled attenuator connected in series, using a vector network analyzer to output different frequency signals to the amplitude and phase control and receive the frequency signal through the amplitude and phase control to calibrate each channel, make a filling table, and a host computer connects the vector network analyzer to the i channels respectively through a switching switch, wherein: the fast amplitude and phase calibration method includes:

[0008] Step 1: Determine the frequency range and step frequency of the transmission signal of the vector network analyzer according to the bandwidth of the entire radar feed network;

[0009] Step 2: dividing the voltage-controlled attenuator state y into m states according to the attenuation dynamic range of the voltage-controlled attenuator, and dividing the voltage-controlled phase shifter state x into n states according to the phase dynamic range of the voltage-controlled phase shifter;

[0010] Step 3: The host computer controls the switch to connect the vector network analyzer to channel 1 of the i channels, transmits the frequency signal according to the frequency range and frequency step, and performs the following steps on the connected channel:

[0011] Step 3.1, initial state acquisition: set the voltage-controlled attenuator and voltage-controlled phase shifter to the initial state, and collect the S parameters of the vector network analyzer at each step frequency initial state, including amplitude and phase data, recorded as initial state A0 and P0;

[0012] Step 3.2: In the initial state of the voltage-controlled attenuator, set the voltage-controlled phase shifter states x, x=0, 1...n in sequence, collect the S parameters of the vector network analyzer in each state, including amplitude and phase data, and obtain the initial phase state, recorded as A0P x ;

[0013] Step 3.3, in the initial state of the voltage-controlled phase shifter, set the voltage-controlled attenuator state y, y = 0, 1 ... m in sequence, collect the S parameters of the vector network analyzer in each state, including amplitude and phase data, and obtain the attenuation initial state, recorded as A y P0;

[0014] Step 3.4, base state calculation, multiply the inverse matrix of the initial state A0 by the phase initial state A0P x , and the phase ground state P0~P n ,Right now The decay initial state A y P0 is multiplied by the inverse matrix of the initial state P0 to obtain the decayed ground state A0~A m ,Right now

[0015] Step 3.5, full state calculation, the decay ground state A0~A m Multiply by the phase ground state P0~P n , we get (m+1)*(n+1) full-state data to form a full-state table, that is, A y P x =A y *P x , that is It contains amplitude and phase values, and the full state table is an ideal model;

[0016] Step 3.6, according to the amplitude, phase range and amplitude, phase step used by the multi-channel feeding network, find the amplitude state and phase state corresponding to each point in the full state table, make a filled table, and complete the calibration of the access channel by the vector network analyzer;

[0017] Step 4: The host computer controls the switching switch to connect the vector network analyzer to another channel, transmits the frequency signal according to the frequency range and frequency step, and returns to step 3.1 until all N channels are connected, completing the calibration of all channels by the vector network analyzer, and completing the multi-channel calibration.

[0018] The scheme is further: the method is further: the 1 channel connected to the i channels is to select any one channel as the reference channel, and step 3.1 further includes executing, calibrating the amplitude and phase of all other channels within the entire feeding network bandwidth to be consistent with the amplitude and phase of the reference channel within the entire feeding network bandwidth.

[0019] The solution is further as follows: in step 2, the state y of the voltage-controlled attenuator is divided into m and the state x of the voltage-controlled phase shifter is divided into n, which is done under the condition that the voltage-controlled attenuator and the voltage-controlled phase shifter meet the use accuracy.

[0020] Beneficial effects of the present invention: The present invention is that during the calibration process, only the initial state data needs to be collected, and then the full state table is generated through base state calculation and full state calculation. Compared with collecting data for each state one by one, this method significantly improves efficiency. For example, the attenuation dynamic range of the voltage-controlled attenuator is 0-25dB. Under the condition of ensuring the accuracy of ±0.1dB, the state of the voltage-controlled attenuator is divided into 301. The phase dynamic range of the voltage-controlled phase shifter is 0-360°. Under the condition of ensuring the accuracy of ±1°, the state of the voltage-controlled phase shifter is divided into 401. In this case, the method only needs to collect the amplitude and phase data of 301+401=702 states, while if each state is collected, it is necessary to collect the amplitude and phase data of 301*401=120701 states. This is only a single channel, and the efficiency improvement is more obvious for multi-channel systems; it saves time compared to manual calibration and traditional calibration methods, which is particularly obvious when the number of channels is large.

[0021] The present invention is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a flow chart of the amplitude and phase calibration of the multi-channel system of the present invention;

[0023] Figure 2 It is a connection diagram of the multi-channel system calibration instrument of the present invention. DETAILED DESCRIPTION

[0024] A fast amplitude and phase calibration method for radar multi-channel and large bandwidth, such as Figure 1 and Figure 2 As shown, the fast amplitude-phase calibration method includes connecting i channels of the radar feed network 1, i=1,2...N, each channel contains an amplitude-phase control 2 composed of a voltage-controlled phase shifter 201 and a voltage-controlled attenuator 202 connected in series, using a vector network analyzer 3 to output different frequency signals to the amplitude-phase control 2 and receive the frequency signal through the amplitude-phase control 2 to calibrate each channel, and make a filling table, a host computer 4 connects the vector network analyzer 3 to the i channels respectively through a switching switch 5, and the host computer 4 also connects the voltage-controlled phase shifter 201 and the voltage-controlled attenuator 202 of the i channels at the same time through the switching switch to control their port voltages; the voltage-controlled phase shifter (Voltage-Controlled Phase Shifter) 201 is an electronic device that can adjust the phase of the input signal by changing the voltage applied to its control port. Voltage-controlled phase shifters are widely used in wireless communications, radar systems, signal processing and other fields. Voltage-controlled phase shifters are also very important in phased array antenna systems. They can be used to dynamically adjust the phase of each antenna element to achieve beamforming and pointing control. This flexibility makes phased array antennas very popular in modern communications and radar systems. Voltage-controlled attenuator (VCA) 202 is an electronic device that can adjust the amount of attenuation of a signal passing through it by changing the voltage applied to its control port. Voltage-controlled attenuators are widely used in wireless communications, test and measurement equipment, and other applications that require dynamic control of signal strength.

[0025] Wherein: the fast amplitude and phase calibration method comprises:

[0026] Step 1: Determine the frequency range and step frequency of the signal transmitted by the vector network analyzer 3 according to the bandwidth of the entire radar feed network 1;

[0027] Step 2: According to the attenuation dynamic range of the voltage-controlled attenuator 202, the voltage-controlled attenuator state y is divided into m states, and according to the phase dynamic range of the voltage-controlled phase shifter 203, the voltage-controlled phase shifter state x is divided into n states;

[0028] Step 3: The host computer 4 controls the switch 5 to connect the vector network analyzer to channel 1 of the i channels, transmits the frequency signal according to the frequency range and the frequency step, and performs the following steps on the connected channel:

[0029] Step 3.1, initial state acquisition: set the voltage-controlled attenuator and voltage-controlled phase shifter to the initial state through the host computer, and collect the S parameters (Scattering parameters) of the vector network analyzer at each step frequency initial state, including amplitude and phase data, recorded as initial state A0, P0;

[0030] Step 3.2, in the initial state of the voltage-controlled attenuator (i.e., the voltage-controlled attenuator is set to the initial state by the host computer), the voltage-controlled phase shifter states are set in sequence (i.e., the voltage-controlled phase shifter states are set in sequence by the host computer) x, x = 0, 1 ... n, and the S parameters of the vector network analyzer under each state of the voltage-controlled phase shifter are collected, including amplitude and phase data, to obtain the initial phase state, recorded as A0P x ;

[0031] Step 3.3, in the initial state of the voltage-controlled phase shifter (i.e., the voltage-controlled phase shifter is set to the initial state by the host computer), the voltage-controlled attenuator state is set in sequence (i.e., the voltage-controlled attenuator state is set in sequence by the host computer) y, y = 0, 1 ... m, and the S parameters of the vector network analyzer under each state of the voltage-controlled attenuator are collected, including amplitude and phase data, to obtain the attenuation initial state, which is recorded as A y P0;

[0032] Step 3.4, base state calculation, multiply the inverse matrix of the initial state A0 by the phase initial state A0P x , and the phase ground state P0~P n ,Right now The decay initial state A y P0 is multiplied by the inverse matrix of the initial state P0 to obtain the decayed ground state A0~A m ,Right now

[0033] Step 3.5, full state calculation, the decay ground state A0~A m Multiply by the phase ground state P0~P n , we get (m+1)*(n+1) full-state data to form a full-state table, that is, A y P x =A y *P x , that is It contains amplitude and phase values, and the full state table is an ideal model;

[0034] Step 3.6, according to the amplitude, phase range and amplitude, phase step used by the multi-channel feeding network, find the amplitude state and phase state corresponding to each point in the full state table, make a filled table, and complete the calibration of the access channel by the vector network analyzer;

[0035] Step 4: The host computer controls the switching switch to connect the vector network analyzer to another channel, transmits the frequency signal according to the frequency range and frequency step, and returns to step 3.1 until all N channels are connected, completing the calibration of all channels by the vector network analyzer, and completing the multi-channel calibration.

[0036] Wherein: the method further comprises: the one channel connected to the i channels is any one channel selected as a reference channel, and step 3.1 further comprises executing to calibrate the amplitude and phase of all the remaining channels within the entire feed network bandwidth to be consistent with the amplitude and phase of the reference channel within the entire feed network bandwidth.

[0037] Wherein: in step 2, the state y of the voltage-controlled attenuator is divided into m and the state x of the voltage-controlled phase shifter is divided into n, which is done under the condition that the voltage-controlled attenuator and the voltage-controlled phase shifter meet the use accuracy.

[0038] The embodiment of the above-mentioned fast amplitude and phase calibration method is that only the initial state data needs to be collected during the calibration process, and then the full state table is generated through the base state calculation and the full state calculation. Compared with collecting data for each state one by one, this method significantly improves efficiency. For example, the attenuation dynamic range of the voltage-controlled attenuator is 0-25dB. Under the condition of ensuring the accuracy of ±0.1dB, the state of the voltage-controlled attenuator is divided into 301. The phase dynamic range of the voltage-controlled phase shifter is 0-360°. Under the condition of ensuring the accuracy of ±1°, the state of the voltage-controlled phase shifter is divided into 401. In this case, the method only needs to collect the amplitude and phase data of 301+401=702 states, while if each state is collected, it is necessary to collect the amplitude and phase data of 301*401=120701 states. This is only a single channel, and the efficiency improvement is more obvious for multi-channel systems; it saves time compared with manual calibration and traditional calibration methods, which is particularly obvious when the number of channels is large.

Claims

1. A fast amplitude and phase calibration method for radar multi-channels with large bandwidth, including i channels connected to a radar feed network, i=1,2...N, each channel having an amplitude and phase control composed of a voltage-controlled phase shifter and a voltage-controlled attenuator connected in series, using a vector network analyzer to output different frequency signals to the amplitude and phase control and receive the frequency signal through the amplitude and phase control to calibrate each channel, making a filling table, a host computer connects the vector network analyzer to the i channels respectively through a switching switch, characterized in that, The fast amplitude and phase calibration method comprises: Step 1: Determine the frequency range and step frequency of the vector network analyzer transmitting signal according to the bandwidth of the entire radar feed network; Step 2: dividing the voltage-controlled attenuator state y into m states according to the attenuation dynamic range of the voltage-controlled attenuator, and dividing the voltage-controlled phase shifter state x into n states according to the phase dynamic range of the voltage-controlled phase shifter; Step 3: The host computer controls the switch to connect the vector network analyzer to channel 1 of the i channels, transmits the frequency signal according to the frequency range and frequency step, and performs the following steps on the connected channel: Step 3.1, initial state acquisition: set the voltage-controlled attenuator to the initial state m0, the voltage-controlled phase shifter to the initial state n0, and collect the S parameters of the vector network analyzer at each step frequency initial state, including amplitude and phase data, recorded as initial state A0, P0; Step 3.2: In the initial state of the voltage-controlled attenuator, set the voltage-controlled phase shifter states x, x = 0, 1, ... n in sequence, collect the S parameters of the vector network analyzer in each state, including amplitude and phase data, and obtain the initial phase state, recorded as A0P x ; Step 3.3, in the initial state of the voltage-controlled phase shifter, set the voltage-controlled attenuator state y, y = 0.1...m in sequence, collect the S parameters of the vector network analyzer in each state, including amplitude and phase data, and obtain the attenuation initial state, recorded as A y P0; Step 3.4, base state calculation, multiply the inverse matrix of the initial state A0 by the phase initial state A0P x , and the phase ground state P0~P n ,Right now The decay initial state A y P0 is multiplied by the inverse matrix of the initial state P0 to obtain the decayed ground state A0~A m ,Right now Step 3.5, full state calculation, the decay ground state A0~A m Multiply by the phase ground state P0~P n , we get (m+1)*(n+1) full-state data to form a full-state table, that is, A y P x =A y *P x , that is It contains amplitude and phase values, and the full state table is an ideal model; Step 3.6, according to the amplitude, phase range and amplitude, phase step used by the multi-channel feeding network, find the amplitude state and phase state corresponding to each point in the full state table, make a filled table, and complete the calibration of the access channel by the vector network analyzer; Step 4: The host computer controls the switching switch to connect the vector network analyzer to another channel, transmits the frequency signal according to the frequency range and frequency step, and returns to step 3.1 until all N channels are connected, completing the calibration of all channels by the vector network analyzer, and completing the multi-channel calibration.

2. The calibration method according to claim 1, characterized in that: The method further comprises: the one channel connected to the i channels is any one channel selected as a reference channel, and step 3.1 further comprises executing to calibrate the amplitude and phase of all the remaining channels within the entire feed network bandwidth to be consistent with the amplitude and phase of the reference channel within the entire feed network bandwidth.

3. The calibration method according to claim 1, characterized in that: In step 2, the state y of the voltage-controlled attenuator is divided into m and the state x of the voltage-controlled phase shifter is divided into n, which is done under the condition that the voltage-controlled attenuator and the voltage-controlled phase shifter meet the use accuracy.

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