A sinusoidal signal phase difference tracing system and method

Abstract

The present invention provides a sinusoidal signal phase difference tracing system and method, which belongs to the field of precision measurement. The sinusoidal signal phase difference tracing system includes: a plurality of identical phase-shifting modules; each phase-shifting module includes a signal input end and a signal output end; the signal input end of the first phase-shifting module is the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, the signal output end of the last phase-shifting module is the signal output end of the system. By cascading the phase-shifting modules, the output signal of the last module is close to the phase of the input signal of the first module. Then, the phase around zero degree can be orthogonally decomposed and measured to solve the tracing problem of the non-zero-degree phase difference of the sinusoidal signal, especially the tracing problem of the orthogonal phase, thereby realizing the tracing of any phase difference.

Description

Technical Field

[0001] The present invention belongs to the field of precision measurement, and in particular relates to a sinusoidal signal phase difference tracing system and method. Background Art

[0002] Phase difference traceability technology plays an important role in precision measurement. For example, in the field of electrical engineering, the traceability of power and loss requires the support of phase difference traceability. In the field of length, dimension measurement and spatial positioning also rely on the precise traceability of the phase difference between two signals.

[0003] Difference measurement technology can be used to accurately trace the source of phase differences around 0 degrees. By using a multiplier to perform orthogonal decomposition of the vector difference of two signals with similar amplitudes and a reference signal, the ratio difference and phase difference between the two signals can be calculated.

[0004] However, in the case of a large phase difference, since the vector difference between the two signals is already large, especially in the orthogonal phase, the vector difference has exceeded the signal itself. Therefore, the above-mentioned difference measurement technology is difficult to guarantee the measurement accuracy of the signal after orthogonal decomposition, and cannot be used for phase difference tracing. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and to provide a sinusoidal signal phase difference tracing system and method, which can achieve tracing at any phase difference.

[0006] The present invention is achieved through the following technical solutions:

[0007] A first aspect of the present invention provides a sinusoidal signal phase difference tracing system, the sinusoidal signal phase difference tracing system comprising: a plurality of identical phase shifting modules;

[0008] Each of the phase-shifting modules includes a signal input end and a signal output end; the signal input end of the first phase-shifting module is the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, the signal output end of the last phase-shifting module is the signal output end of the system.

[0009] The system includes N phase shift modules;

[0010] Each phase shift module can achieve 360 / N degree phase shift;

[0011] Each phase shift module adopts a phase shift circuit composed of a resistor and a capacitor, or a phase shift circuit composed of a resistor and an inductor, or a phase shift circuit composed of a resistor, a capacitor and an operational amplifier, or a digital phase shifter.

[0012] Preferably, each of the phase shift modules includes: a first operational amplifier, a second operational amplifier, a resistor R and a capacitor C;

[0013] The non-inverting input terminal of the first operational amplifier is the signal input terminal of the phase shift module, the inverting input terminal of the first operational amplifier is connected to its signal output terminal, the signal output terminal of the first operational amplifier is connected to one end of the resistor R, and the other end of the resistor R is connected to the non-inverting input terminal of the second operational amplifier and one end of the capacitor C; the signal output terminal of the second operational amplifier is connected to its inverting input terminal, and the signal output terminal of the second operational amplifier is also the signal output terminal of the phase shift module; the other end of the capacitor C is grounded.

[0014] Further, the system includes a housing;

[0015] All phase shifting modules are installed in the inner cavity of the housing;

[0016] A plurality of holes are opened on the shell, and the signal input end of the system and the signal output end of the system are respectively led out from the holes.

[0017] Furthermore, the signal output ends of the phase shift modules are respectively led out from the holes on the housing to serve as the intermediate angle signal output ends.

[0018] A second aspect of the present invention provides a method for tracing a sinusoidal signal phase difference, the method comprising:

[0019] (1) Set up N+1 phase shift modules, namely PS0, PS1 to PSN;

[0020] (2) Use PS0 to adjust PS1 to PSN to phase shift modules with the same phase shift angle;

[0021] (3) Cascade PS1 to PSN into the above system;

[0022] (4) tracing the system;

[0023] (5) calibrating the digital phase shifter to be calibrated using the system;

[0024] (6) Using the digital phase shifter to generate arbitrary phase shift angles, other phase shifting devices can be traced back to their source.

[0025] The operation of step (2) includes:

[0026] Perform the following operations on the N phase shift modules from PS1 to PSN in sequence:

[0027] Input an input signal to the signal input terminals of PS0 and PSi respectively, i=1, 2, ..., N;

[0028] The difference measuring device is used to measure the ratio difference and phase difference between the output signal of PS0 and the output signal of PSi;

[0029] Adjust the parameters of PSi to minimize the phase difference between its output signal and the output signal of PS0.

[0030] The operation of step (3) includes:

[0031] The signal input end of the first phase-shifting module is used as the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, and the signal output end of the Nth phase-shifting module is used as the signal output end of the system.

[0032] The operation of step (4) includes:

[0033] The phase difference between the input signal and the output signal of the system is obtained by using a difference measuring device, and the phase difference is divided by N to obtain the phase difference of each phase shift module of 360 / N degrees, that is, the traceability of the phase shift of each N phase shift module of 360 / N degrees is achieved;

[0034] There are M intermediate angle signal output terminals, M = N-1, then the j-th intermediate angle signal output terminal realizes a phase shift of j*360 / N degrees, j = 1, 2, ..., M;

[0035] The phase difference of each phase shift module j*360 / N degrees is used to obtain the phase difference of the jth intermediate angle signal output end, that is, the traceability of the jth intermediate angle is realized, and the traceability of the system is completed.

[0036] The operation of step (5) includes:

[0037] Take j*360 / N degrees at the middle angle signal output end as the standard value;

[0038] Use the digital phase shifter to be calibrated to generate a phase shift of j*360 / N degrees;

[0039] The output signal generated by the digital phase shifter to be calibrated and the output signal of the corresponding intermediate angle signal output terminal are simultaneously input into the difference measuring device, and the phase difference between the two is obtained by using the difference measuring device, thereby achieving the calibration of the digital phase shifter to be calibrated.

[0040] Compared with the prior art, the beneficial effects of the present invention are: the present invention cascades multiple phase-shifting modules so that the output signal of the last phase-shifting module is close in phase to the input signal of the first phase-shifting module, and then uses the orthogonal decomposition measurement of the phase around zero degree to solve the tracing problem of the non-zero phase difference of the sinusoidal signal, especially the tracing problem of the orthogonal phase, thereby realizing the tracing of any phase difference. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of a phase shift module in one embodiment of the present invention;

[0042] Figure 2 A phase shift module testing and adjustment circuit in one embodiment of the present invention;

[0043] Figure 3 A schematic diagram of the structure of a sinusoidal signal phase difference tracing system in one embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present invention is described in further detail below with reference to the accompanying drawings:

[0045] The present invention is based on the concept that the phase difference between two signals is a relative ratio of the time difference to the period, rather than an absolute value. The definition of the orthogonal phase difference (90 degrees) is one quarter of a period (360 degrees).

[0046] The sinusoidal signal phase difference tracing system of the present invention includes: multiple identical phase-shifting modules, each of which can realize phase shifting, and each of which includes a signal input end and a signal output end; multiple phase-shifting modules are cascaded to form the system, specifically, the signal input end of the first phase-shifting module is the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, the signal output end of the last phase-shifting module is the signal output end of the system.

[0047] Furthermore, the system includes a shell, and all phase shifting modules are installed in the inner cavity of the shell; a plurality of holes are opened on the shell, and the signal input end and the signal output end of the system extend from the holes respectively, so as to facilitate connection with the input signal outside the shell and the digital phase shifter to be calibrated respectively.

[0048] Furthermore, the signal output ends of the phase shift modules in the housing can be led out from the holes on the housing to serve as the intermediate angle signal output ends.

[0049] The embodiments of the present invention are as follows:

[0050] Example 1:

[0051] All phase shifting modules in the system can adopt various existing devices capable of achieving phase shifting, such as a phase shifting circuit composed of resistors and capacitors, or a phase shifting circuit composed of resistors and inductors, or a phase shifting circuit composed of resistors, capacitors and operational amplifiers, or a digital phase shifter, etc.

[0052] Example 2:

[0053] Preferably, Figure 1 As shown, each phase shift module includes: two operational amplifiers (i.e. followers), namely a first operational amplifier OPA1 and a second operational amplifier OPA2, as well as a resistor R and a capacitor C. The specific structure is as follows:

[0054] The non-inverting input terminal of the first operational amplifier OPA1 is the signal input terminal of the phase shift module, which is connected to the input signal. The inverting input terminal of the first operational amplifier OPA1 is connected to its signal output terminal. The signal output terminal of the first operational amplifier OPA1 is connected to one end of the resistor R, and the other end of the resistor R is connected to the non-inverting input terminal of the second operational amplifier OPA2 and one end of the capacitor C; the signal output terminal of the second operational amplifier OPA2 is connected to its inverting input terminal, and the signal output terminal of the second operational amplifier OPA2 is the signal output terminal of the phase shift module; the other end of the capacitor C is grounded. Figure 1 The box on the left side of the middle represents the signal input end of the phase shift module, and the box on the right side represents the signal output end of the phase shift module. Figure 1 The resistor R and capacitor C in the circuit are both adjustable resistors and capacitors.

[0055] Example 3:

[0056] like Figure 3 As shown, N in this embodiment is equal to 4, that is, the sinusoidal signal phase difference tracing system includes four phase shifting modules, namely the first phase shifting module PS1, the second phase shifting module PS2, the third phase shifting module PS3, and the fourth phase shifting module PS4. The first operational amplifier in the first phase shifting module PS1 is OPA11, the second operational amplifier is OPA12, the resistor is R1, and the capacitor is C1. The first operational amplifier in the second phase shifting module PS2 is OPA21, the second operational amplifier is OPA22, the resistor is R2, and the capacitor is C2, and so on.

[0057] Each phase shift module can achieve a ninety-degree phase shift, and the four phase shift modules are cascaded in sequence, that is, the signal output end of the previous phase shift module is connected to the signal input end of the next phase shift module, and the signal input end of the first phase shift module is used as the signal input end of the system, and the signal output end of the last phase shift module is used as the signal output end of the system. Figure 3 , the signal input end of PS1 is used as the signal input end of the system, the signal output end of PS1 is connected to the signal input end of PS2, the signal output end of PS2 is connected to the signal input end of PS3, the signal output end of PS3 is connected to the signal input end of PS4, and the signal output end of PS4 is used as the signal output end of the system.

[0058] In this way, the initial input signal TI(t) can be transformed into an output signal TO(t) having a phase difference of approximately 360 degrees (ie, zero degree) from the initial input signal after passing through the four phase shift modules.

[0059] Example 4:

[0060] Furthermore, in this embodiment, there are three intermediate angle output terminals, such as Figure 3 As shown, the signal output ends of the first phase shift module PS1, the second phase shift module PS2, and the third phase shift module PS3 are respectively led out as intermediate angle signal output ends TA, TB, and TC, where the phase difference between TA and TI is 90°, the phase difference between TB and TI is 180°, and the phase difference between TC and TI is 270°. These output ports can then be used to calibrate the corresponding phase of the digital phase shifter to be calibrated. For example, TB can be used to calibrate whether the 180-degree phase shift of the digital phase shifter to be calibrated is accurate.

[0061] Embodiment 5:

[0062] A 60-degree phase shift module can also be designed using the method disclosed herein. Specifically, by configuring different resistor R and capacitor C values in the phase shift module of Example 1, a desired phase shift angle can be achieved at a desired frequency. Furthermore, six 60-degree phase shift modules can be cascaded (similar to the connection method in Example 3) to replace four 90-degree phase shifters to achieve a 360-degree phase shift.

[0063] It's also possible to cascade N other similar 360 / N-degree phase-shifting modules to achieve a 360-degree phase shift. Of course, similar to the system consisting of four 90-degree phase-shifting modules mentioned above, the signal output terminals of each phase-shifting module can also be connected as intermediate-angle signal output terminals, thereby achieving phase shifts at multiple intermediate angles. Given M intermediate-angle signal output ports, where M = N-1, the jth angle signal output port achieves a j*360 / N-degree phase shift, where j = 1, 2, ..., M.

[0064] Alternatively, a 180-degree phase shift can be achieved by combining N phase shift modules in cascade, and then connecting an inverter to achieve a 360-degree phase shift.

[0065] Example 6:

[0066] Preferably, all phase shift modules can be encapsulated in a housing, and a hole is opened in the housing, and the signal input end and each signal output end extend from the hole to facilitate the connection of input signals and the output of signals. Figure 3 The thick black lines on the periphery (i.e., the lines between T0 and T1, T1 and TA, TA and TB, and TB and TC) represent the shell that encapsulates these phase shift modules.

[0067] Embodiment seven:

[0068] The steps of the method of the present invention include:

[0069] Step 1: Set up five phase shift modules as shown in Example 2, namely PS0, PS1, PS2, PS3, and PS4;

[0070] Step 2: If Figure 2 As shown, a signal is simultaneously input into the 90-degree phase-shift module PS0 (the five phase-shift modules are identical, and any one of them is selected as PS0) used as a reference, and the debugged 90-degree phase-shift module PS1. The phase difference between the output signals of PS0 and PS1 relative to the input signal should be about 90 degrees. A difference measuring device in the existing difference measurement technology is used (an existing lock-in amplifier or an instrument with similar functions can be used as the difference measuring device. The difference measuring principle is based on the existing lock-release principle, which will not be described here). The ratio difference and phase difference of the two output signals of PS0 and PS1 are measured, and the device parameters of PS1 are adjusted (the parameters of the resistor R or the capacitor C can be adjusted. The adjustment method adopts the existing adjustment method.) so that the phase difference between its output signal and the output signal of PS0 is minimized;

[0071] Step 3: Repeat step 2 for PS2, PS3, and PS4, performing similar measurements and adjustments as for PS1, so that the phase shift angles of the four phase shift modules PS1, PS2, PS3, and PS4 are the same.

[0072] Step 4: If Figure 3 As shown, the four modules PS1, PS2, PS3, and PS4 are cascaded to form the aforementioned system, with the signal input of the first phase-shifting module serving as the system's signal input, and the signal output of the last phase-shifting module serving as the system's signal output. This allows the initial input signal TI(t) to pass through the four phase-shifting modules and produce an output signal TO(t) with a phase difference of approximately 360 degrees (i.e., zero degrees) from the initial input signal.

[0073] A difference measuring device is used to obtain the phase difference between the input signal TI(t) and the output signal TO(t). After obtaining the phase difference, the phase difference is divided by N (N is 4 in this embodiment) to obtain the phase difference of the four phase shifting modules with each phase shifted by ninety degrees (also corresponding to j=1). This can achieve the traceability of the ninety-degree phase shift of the four phase shifting modules PS1, PS2, PS3, and PS4. At the same time, according to the combination, the traceability of one hundred and eighty degrees and two hundred and seventy degrees can also be achieved. Specifically, the error of the phase shift of one hundred and eighty degrees is 2 multiplied by the error of the phase shift of ninety degrees (corresponding to j=2), and the error of the phase shift of two hundred and seventy degrees is 3 multiplied by the error of the phase shift of ninety degrees (corresponding to j=3).

[0074] Figure 3 TA, TB, and TC are used as intermediate angle output terminals, respectively. The phase difference between TA and TI is 90°, the phase difference between TB and TI is 180°, and the phase difference between TC and TI is 270°. These output ports can then be used to calibrate the corresponding phase shift angles of the digital phase shifter. The phase difference of each phase shift module is obtained and the traceability of the phase shift module is achieved. Adjustments to each phase shift module are then unnecessary. The phase difference can be used to correct the measurement results in subsequent use. Alternatively, the device parameters of the phase shift module, such as the resistor and capacitor parameters, can be adjusted to correct this phase difference.

[0075] Step 5: Using the traced phase difference, the phase shift accuracy of the existing digital phase shifter to be calibrated, which can generate any phase shift angle, can be calibrated to 90 degrees, 180 degrees, and 270 degrees.

[0076] The specific calibration method is as follows: Because the existing differential measuring device can accurately trace the phase difference around zero degree, the existing differential measuring device is used to directly measure the zero-degree phase shift error of the digital phase shifter to be calibrated: two signals with zero phase difference (one is the original input signal, and the other is the signal after zero-degree phase shift by the digital phase shifter) are input into the differential measuring device, and the proportional difference and phase difference are obtained using the differential measuring device, that is, the zero-degree phase shift error of the digital phase shifter to be calibrated is obtained.

[0077] Because the existing difference measuring device cannot achieve accurate tracing of larger angular phase differences, the above-mentioned system is used to measure the errors of other angular phase shifts of the digital phase shifter to be calibrated. Specifically, the phase of the output signal of the intermediate angle output end of the above-mentioned system is used as the standard value, and these phases are respectively generated by the digital phase shifter to be calibrated. The output signal generated by the digital phase shifter to be calibrated and the output signal of a certain intermediate angle output end are simultaneously input into the difference measuring device to obtain the error of the digital phase shifter to be calibrated. The error includes the proportional difference and phase difference obtained by the difference measuring device. Obtaining the error means that calibration is achieved. Furthermore, in actual applications, the phase shift angle of the digital phase shifter to be calibrated can also be adjusted according to the error to minimize the error value. Alternatively, the phase shift angle of the digital phase shifter to be calibrated can be left unchanged, and the error can be used to directly correct the measurement result during subsequent tracing.

[0078] For example, if the 90-degree phase shift error of the digital phase shifter to be calibrated is to be calibrated, the digital phase shifter to be calibrated is operated to generate an output signal with a 90-degree phase difference with the input signal through software control of the digital signal, and the input signal is input to the digital phase shifter. Figure 3 The signal input terminal TI of the system shown in the figure is then connected to the output signal of the digital phase shifter to be calibrated. Figure 3 The output signals from the TA output port of the system are simultaneously input into a difference measurement device to obtain the error of the digital phase shifter to be calibrated. Similarly, the same process can be used to calibrate errors at phase shift angles such as 180° and 270°.

[0079] Because four representative angles that are equally divided within a 360-degree cycle are selected to divide a cycle into four quadrants, and the other angles are all within these four quadrants, after the four phase errors of 0°, 90°, 180°, and 270° of the digital phase shifter to be calibrated are calibrated, the phase errors of other angles will not exceed the largest error among these four errors.

[0080] Step 6. After completing the above calibration, the digital phase shifter can be used to generate any phase shift angle. The calibrated digital phase shifter can be used as a standard for tracing other phase shifting devices. That is, the calibrated digital phase shifter is used to generate a certain phase difference, and the same phase difference is generated by other phase shifting devices. The output signals of the two are respectively input into the difference measuring device to obtain the phase difference of the two output signals, thereby realizing the traceability of any phase difference.

[0081] This embodiment uses the 90-degree phase shift module shown in the second embodiment as an example to illustrate the steps of the method. If a phase shift module with other phase shift angles is used, the method is similar to that of this embodiment and will not be repeated.

[0082] The present invention solves the problem of 90 / 180 / 270 degree traceability by cascading the four 90-degree phase-shifting modules. Five 72-degree phase-shifting modules can also be used to solve the problem of 72 / 144 / … degree traceability. This method can also solve the problem of 360 / N degree traceability, thereby solving the problem of 0 / 90 / 180 / 270 degree traceability of the digital phase shifter. This also solves the problem of traceability of any angle of the digital phase shifter, thereby realizing the traceability of any phase difference.

[0083] The above technical solution is only one embodiment of the present invention. For those skilled in the art, it is easy to make various types of improvements or modifications based on the application methods and principles disclosed in the present invention, and it is not limited to the method described in the above specific embodiment of the present invention. Therefore, the method described above is only preferred and does not have a restrictive meaning.

Claims

1. A method for tracing the phase difference of a sinusoidal signal, characterized by: The method comprises: (1) Set up N+1 phase shift modules, namely PS0, PS1 to PSN; (2) Use PS0 to adjust PS1 to PSN to phase shift modules with the same phase shift angle; (3) Cascade PS1 to PSN to form a sinusoidal signal phase difference tracing system; (4) tracing the system; (5) calibrating the digital phase shifter to be calibrated using the system; (6) using the digital phase shifter to generate arbitrary phase shift angles and trace other phase shifting devices; The operation of step (4) includes: The phase difference between the input signal and the output signal of the system is obtained by using a difference measuring device, and the phase difference is divided by N to obtain the phase difference of each phase shift module at a phase shift of 360 / N degrees; There are M intermediate angle signal output terminals, M = N-1, then the j-th intermediate angle signal output terminal realizes a phase shift of j*360 / N degrees, j = 1, 2, ..., M; The phase difference of the jth intermediate angle signal output end is obtained by using j*j*each phase shift module to shift the phase difference by 360 / N degrees.

2. The sinusoidal signal phase difference tracing method according to claim 1, characterized in that: The sinusoidal signal phase difference tracing system includes: a plurality of identical phase shifting modules; Each of the phase-shifting modules includes a signal input end and a signal output end; the signal input end of the first phase-shifting module is the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, the signal output end of the last phase-shifting module is the signal output end of the system.

3. The sinusoidal signal phase difference tracing method according to claim 2, characterized in that: The system includes N phase shift modules; Each phase shift module can achieve 360 / N degree phase shift; Each phase shift module adopts a phase shift circuit composed of a resistor and a capacitor, or a phase shift circuit composed of a resistor and an inductor, or a phase shift circuit composed of a resistor, a capacitor and an operational amplifier, or a digital phase shifter.

4. The sinusoidal signal phase difference tracing method according to claim 3, characterized in that: Each of the phase shift modules includes: a first operational amplifier, a second operational amplifier, a resistor R and a capacitor C; The non-inverting input terminal of the first operational amplifier is the signal input terminal of the phase shift module, the inverting input terminal of the first operational amplifier is connected to its signal output terminal, the signal output terminal of the first operational amplifier is connected to one end of the resistor R, and the other end of the resistor R is connected to the non-inverting input terminal of the second operational amplifier and one end of the capacitor C; the signal output terminal of the second operational amplifier is connected to its inverting input terminal, and the signal output terminal of the second operational amplifier is also the signal output terminal of the phase shift module; the other end of the capacitor C is grounded.

5. The sinusoidal signal phase difference tracing method according to claim 2, characterized in that: The system includes a housing; All phase shifting modules are installed in the inner cavity of the housing; A plurality of holes are opened on the shell, and the signal input end of the system and the signal output end of the system are respectively led out from the holes.

6. The sinusoidal signal phase difference tracing method according to claim 5, characterized in that: The signal output ends of the phase shift modules are respectively led out from the holes on the housing to serve as intermediate angle signal output ends.

7. The sinusoidal signal phase difference tracing method according to claim 1, characterized in that: The operation of step (2) includes: Perform the following operations on the N phase shift modules from PS1 to PSN in sequence: Input an input signal to the signal input terminals of PS0 and PSi simultaneously, i=1, 2, ..., N; The difference measuring device is used to measure the ratio difference and phase difference between the output signal of PS0 and the output signal of PSi; Adjust the parameters of PSi to minimize the phase difference between its output signal and the output signal of PS0.

8. The method for tracing the phase difference of a sinusoidal signal according to claim 1, wherein: The operation of step (3) includes: The signal input end of the first phase-shifting module is used as the signal input end of the system, the signal output end of the first phase-shifting module is connected to the signal input end of the second phase-shifting module, the signal output end of the second phase-shifting module is connected to the signal input end of the third phase-shifting module, and so on, and the signal output end of the Nth phase-shifting module is used as the signal output end of the system.

9. The method for tracing the phase difference of a sinusoidal signal according to claim 1, wherein: The operation of step (5) includes: Take j*360 / N degrees at the middle angle signal output end as the standard value; Use the digital phase shifter to be calibrated to generate a phase shift of j*360 / N degrees; The output signal generated by the digital phase shifter to be calibrated and the output signal of the corresponding intermediate angle signal output terminal are simultaneously input into the difference measuring device, and the phase difference between the two is obtained by using the difference measuring device.

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