Phase characteristic measuring device, signal generator and signal analyzer including the same, and phase characteristic measuring method

Abstract

To provide a phase characteristics measuring instrument and the like that uses a voltmeter and a wave detector not requiring a high-speed trigger operation to avoid increase in the scale of an apparatus used for phase measurement, and thereby can achieve phase measurement at a relatively low price.SOLUTION: A phase characteristics measuring instrument comprises: a first wave detector 11 that receives and detects two patterns of three-tone signals, a first three-tone signal obtained by combining the three waves of angular frequencies ω1,ω2,ω3 (wherein ω2-ω1=ω3-ω2=Δω) and a second three-tone signal obtained by changing the phase of one tone of the first three-tone signal; a BPF 12 that allows only a beat component of an angular frequency difference Δω of adjacent waves of the three-tone signal from the signal output from the first wave detector to pass therethrough; a second wave detector 13 that detects power of the beat component that has passed through the BPF 12; a voltmeter 14 that measures the voltage of the signal output from the second wave detector; and a phase calculator 15 that calculates the phase on the basis of the measured voltage value.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a phase characteristic measuring device, a signal generating device and a signal analyzing device including the same, and a phase characteristic measuring method. [Background technology]

[0002] To improve the transmission speed of wireless communications, communication methods that use broadband modulated signals in the millimeter, submillimeter, and terahertz wave bands, which have higher carrier frequencies than conventional methods, are being considered. Hereinafter, the millimeter, submillimeter, and terahertz wave bands will be referred to as high-frequency bands, and signals in high-frequency bands will be collectively referred to as high-frequency signals.

[0003] Generally, as frequencies become higher and wider, the phase frequency characteristics of the frequency conversion section (up-converter or down-converter) of high-frequency band signal generators and high-frequency band signal measuring instruments cannot be ignored, so it is important to calibrate the phase characteristics of the frequency conversion section.In addition, in multi-level quadrature amplitude modulation systems, which have high spectral efficiency, even small phase errors can cause degradation of transmission characteristics, so accurate calibration of the phase characteristics is required. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5572590 [Patent Document 2] Patent No. 6839226 Summary of the Invention [Problem to be solved by the invention]

[0005] The conventional technology described in Patent Document 1 is a technology that measures the phase frequency characteristics (simply referred to as phase characteristics) by inputting two high-frequency tone signals, such as millimeter waves, into an envelope detector (simply referred to as a detector), measuring the beat between the tones with the detector, and detecting the phase difference between the tones. However, this method requires determining the initial phase of the beat between the tone signals. To determine the initial phase, a trigger must be applied to an analog-to-digital converter (ADC) that acquires the time waveform of the detector output signal, and synchronization with the tone signal generator must be achieved. Such high-speed triggering operation poses the problem of requiring high-cost components.

[0006] To solve the above problem, there is a method for acquiring the time waveform of three-tone signals in a high-frequency band such as a millimeter wave and calculating the phase characteristics. Using three-tone signals makes it possible to measure the phase characteristics even when there is no ADC trigger and the initial phase is unknown. Examples of measurements using three-tone signals include electro-optic sampling (see, for example, Patent Document 2) and down-conversion of high-frequency signals such as millimeter waves. In particular, electro-optic sampling can accurately determine the phase characteristics of very high frequencies. However, this method requires an optical system such as a femtosecond laser, which increases the device's size. Down-conversion methods require a local signal in a high-frequency band such as a millimeter wave, which increases the device's size.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide a phase characteristic measuring device that can perform phase measurement relatively inexpensively without increasing the scale of the device used for phase measurement, a signal generating device and a signal analyzing device that include the same, and a phase characteristic measuring method. [Means for solving the problem]

[0008] To achieve the above object, the phase characteristic measuring instrument according to the present invention is characterized by comprising: a first detector (11) that receives and detects a first three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following equation (1) and a second three-tone signal obtained by combining three waves e'1, e'2, and e'3 expressed by the following equation (2); a band-pass filter (12) that passes, of the signals output from the first detector, frequency components of the first and second three-tone signals having frequencies corresponding to an angular frequency difference Δω between adjacent waves, and blocks frequency components that are twice the angular frequency difference Δω and DC components; a second detector (13) that detects the signal that has passed through the band-pass filter; a voltmeter (14) that measures the voltage of the signal output from the second detector; and a phase calculator (15) that calculates the phase φ2″ expressed by the following equation (3).

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[0009] With this configuration, the power of the beat component of angular frequency Δω is measured with the second detector for two patterns of three-tone signals: the first three-tone signal expressed by the above formula (1) and the second three-tone signal expressed by the above formula (2), which has one tone phase shifted.This makes it possible to calculate the phase relationship (second-order differential value) of the three tones expressed by the above formula (3).By using a voltmeter and detector that do not require high-speed triggering, it is possible to provide a phase characteristics measuring instrument that can achieve phase measurement at a relatively low cost without increasing the scale of the equipment.

[0010] Furthermore, to achieve the above object, the phase characteristic measuring instrument according to the present invention is characterized by comprising: a first detector (11) that receives and detects a three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following equation (4); a band-pass filter (12) that passes, of the signal output from the first detector, a frequency component of the three-tone signal having an angular frequency difference Δω between adjacent waves, and blocks a frequency component that is twice the angular frequency difference Δω and a DC component; a second detector (13) that detects the signal that has passed through the band-pass filter; a voltmeter (14) that measures the voltage of the signal output from the second detector; and a phase calculator (15) that calculates the phase φ2″ expressed by the following equation (5).

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[0011] With this configuration, by measuring the power of the beat component of the angular frequency Δω for the three-tone signal of three patterns (ψ=0, π / 2, π) expressed by the above equation (4) with the second detector, it is possible to calculate the phase relationship (second-order differential value) of the three tones expressed by the above equation (5), even if the amplitudes a1, a2, a3 of the three-tone signal are unknown and not equal to each other. As a result, by using a voltmeter and detector that do not require high-speed triggering, it is possible to provide a phase characteristics measuring instrument that can avoid increasing the scale of the equipment and achieve phase measurement at a relatively low cost. In addition, E beat (ψ) It is not affected by offsets that occur during measurement.

[0012] To achieve the above object, the phase characteristic measuring device according to the present invention is characterized by comprising: a first detector (11) that receives and detects a three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following equation (6); a band-pass filter (12) that passes, of the signal output from the first detector, a frequency component of the three-tone signal whose frequency is the angular frequency difference Δω between adjacent waves, and blocks a frequency component that is twice the angular frequency difference Δω and a DC component; a second detector (13) that detects the signal that has passed through the band-pass filter; a voltmeter (14) that measures the voltage of the signal output from the second detector; and a phase calculator (15) that calculates the phase φ2″ expressed by the following equation (7).

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[0013] With this configuration, by measuring the power of the beat component of the angular frequency Δω for the three-tone signal of three patterns (ψ=0, π / 2, π) expressed by the above equation (6) with the second detector, it is possible to calculate the phase relationship (second-order differential value) of the three tones expressed by the above equation (11) even if the amplitudes a1, a2, a3 of the three-tone signal are unknown and not equal to each other. By using the atan2 function in the above equation (7), the tan -1 The phase measurement range is wider than when using the E function. This makes it possible to provide a phase characteristic measuring instrument that can perform phase measurement at a relatively low cost without increasing the scale of the equipment by using a voltmeter or detector that does not require high-speed triggering. beat (ψ) It is not affected by offsets that occur during measurement.

[0014] A signal generating device according to the present invention comprises a high-frequency signal generating unit (2) that generates a high-frequency signal and a three-tone signal; a coupler (3) that branches the signal output from the high-frequency signal generating unit and outputs one of the signals as an output signal; and any of the phase characteristic measuring devices (1) described above that, when the high-frequency signal generating unit generates the three-tone signal, receives as input the other signal branched by the coupler and measures the phase of the input three-tone signal to measure the phase characteristics of the high-frequency signal generating unit, and is characterized in that, when the high-frequency signal generating unit generates the high-frequency signal, the phase characteristics of the high-frequency signal are corrected based on the phase characteristics of the high-frequency signal generating unit measured by the phase characteristic measuring device.

[0015] This configuration provides the same effects as those described above for the phase characteristic measuring device, and also makes it possible to correct the phase characteristics of the high-frequency signal generating unit based on the phase characteristics of the high-frequency signal generating unit measured by the phase characteristic measuring device, thereby making it possible to generate a high-frequency signal with good phase characteristics.

[0016] A signal analysis device according to the present invention includes a reference signal generating unit (20) that generates a reference signal and a three-tone signal, a coupler (3) that branches the signal output from the reference signal generating unit, any one of the phase characteristic measuring devices (1) described above that receives one of the signals branched by the coupler when the reference signal generating unit generates the three-tone signal and measures the phase characteristic of the reference signal generating unit by measuring the phase of the input three-tone signal, a switch (4) that selects either the other signal branched by the coupler or the input signal, and a high-frequency signal analyzing unit (5) that analyzes the signal selected by the switch. and when the reference signal generating unit generates the reference signal and the other signal branched by the coupler is selected by the switch, the phase characteristic of the high frequency signal analyzing unit is calculated from the phase characteristic of the reference signal measured by the high frequency signal analyzing unit and the phase characteristic of the reference signal generating unit measured by the phase characteristic measuring instrument, and when the input signal is selected by the switch, the phase characteristic when the high frequency signal analyzing unit analyzes the input signal is corrected based on the calculated phase characteristic of the high frequency signal analyzing unit, and signal analysis of the input signal with the corrected phase characteristic is performed.

[0017] As described above, the phase characteristics of the reference signal generating unit are measured by the phase characteristics measuring device, and a signal having known phase characteristics is input from the reference signal generating unit to the high frequency signal analyzing unit, thereby measuring the phase characteristics of the high frequency signal analyzing unit, correcting the phase characteristics of the high frequency signal analyzing unit based on the measured phase characteristics of the high frequency signal analyzing unit, and performing signal analysis of the input signal by the high frequency signal analyzing unit with the corrected phase characteristics. This provides the same effects as those described above for the phase characteristics measuring device, and also makes it possible to perform signal analysis with the corrected phase characteristics, thereby improving the quality of the analysis.

[0018] To achieve the above object, the phase characteristic measuring method according to the present invention includes a first three-tone signal generating step of generating a first three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following formula (8): a first detection step of detecting the first three-tone signal; a first band-pass filtering step of passing a frequency component of the first three-tone signal having a frequency corresponding to an angular frequency difference Δω between adjacent waves of the first three-tone signal and blocking a frequency component twice the angular frequency difference Δω and a DC component from the signal obtained by the first detection step; a second detection step of detecting the signal passed through the first band-pass filtering step; a first voltage measurement step of measuring the voltage of the signal obtained by the second detection step; and a second three-tone signal obtained by combining three waves e′1, e′2, and e′3 expressed by the following formula (9): a second band-pass filtering step of passing a frequency component of the second three-tone signal having an angular frequency difference Δω between adjacent waves of the second three-tone signal from the signal obtained by the third detection step and blocking a frequency component of twice the angular frequency difference Δω and a DC component; a fourth detection step of detecting the signal that has passed through the second band-pass filtering step; a second voltage measurement step of measuring a voltage of the signal obtained by the fourth detection step; and a phase calculation step of calculating a phase φ″ expressed by the following equation (10) from the voltage value measured in the first voltage measurement step and the voltage value measured in the second voltage measurement step.

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[0019] With this configuration, by measuring the power of the beat component of angular frequency Δω for two patterns of three-tone signals: the first three-tone signal expressed by the above equation (8) and the second three-tone signal expressed by the above equation (9) with the phase of one of the tones changed, it is possible to calculate the phase relationship (second-order differential value) of the three tones expressed by the above equation (10).This makes it possible to provide a phase characteristics measurement method that can achieve phase measurement relatively inexpensively without using large-scale equipment, by using a voltmeter or detector that does not require high-speed triggering operation.

[0020] To achieve the above object, a phase characteristics measurement method according to the present invention includes: a three-tone signal generation step of generating a three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following equation (11); a first detection step of detecting the three-tone signal; a band-pass filter step of passing, from the signal obtained by the first detection step, a frequency component of the three-tone signal whose frequency is the angular frequency difference Δω between adjacent waves, and cutting off a frequency component that is twice the angular frequency difference Δω and a DC component; a second detection step of detecting the signal that has passed through the band-pass filter step; a voltage measurement step of measuring the voltage of the signal obtained by the second detection step; and a phase calculation step of setting the phase ψ of the following equation (11) to 0, π / 2, and π, and calculating a phase φ″ expressed by the following equation (12) from each voltage value measured by executing the three-tone signal generation step, the first detection step, the band-pass filter step, the second detection step, and the voltage measurement step, respectively.

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[0021] With this configuration, by measuring the power of the beat component of the angular frequency Δω for the three-tone signal of three patterns (ψ=0, π / 2, π) expressed by the above equation (11), it is possible to calculate the phase relationship (second-order differential value) of the three tones expressed by the above equation (12), even if the amplitudes a1, a2, a3 of the three-tone signal are unknown and not equal to each other. This makes it possible to provide a phase characteristic measurement method that can realize phase measurement relatively inexpensively without using large-scale equipment by using a voltmeter or detector that does not require high-speed trigger operation. In addition, E beat (ψ) It is not affected by offsets that occur during measurement.

[0022] To achieve the above object, a phase characteristics measurement method according to the present invention includes: a three-tone signal generation step of generating a three-tone signal obtained by combining three waves e1, e2, and e3 expressed by the following equation (13); a first detection step of detecting the three-tone signal; a band-pass filter step of passing, from the signal obtained by the first detection step, a frequency component of the three-tone signal having a frequency equal to the angular frequency difference Δω between adjacent waves, and blocking a frequency component that is twice the angular frequency difference Δω and a DC component; a second detection step of detecting the signal that has passed through the band-pass filter step; a voltage measurement step of measuring the voltage of the signal obtained by the second detection step; and a phase calculation step of setting the phase ψ of the following equation (13) to 0, π / 2, and π, and calculating a phase φ″ expressed by the following equation (14) from each voltage value measured by executing the three-tone signal generation step, the first detection step, the band-pass filter step, the second detection step, and the voltage measurement step, respectively.

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[0023] With this configuration, by measuring the power of the beat component of the angular frequency Δω for the three-tone signal of three patterns (ψ=0, π / 2, π) expressed by the above equation (13), even if the amplitudes a1, a2, a3 of the three-tone signal are unknown and not equal to each other, the phase relationship (second-order differential value) of the three tones expressed by the above equation (14) can be calculated. By using the atan2 function in the above equation (14), the tan -1 The phase measurement range is wider than when using the E function. This makes it possible to provide a phase characteristic measurement method that can realize phase measurement at a relatively low cost without using a large-scale device by using a voltmeter or detector that does not require high-speed trigger operation. beat (ψ) It is not affected by offsets that occur during measurement.

[0024] A signal generation method according to the present invention includes: a three-tone signal generation step of generating a three-tone signal using a high-frequency signal generation unit; any of the phase characteristics measurement methods described above, in which the phase characteristics of the high-frequency signal generation unit are measured by measuring the phase of the three-tone signal generated in the three-tone signal generation step; and a high-frequency signal generation step of generating a high-frequency signal using the high-frequency signal generation unit and outputting it as an output signal, and is characterized in that the phase characteristics of the high-frequency signal are corrected based on the phase characteristics of the high-frequency signal generation unit measured by the phase characteristics measurement method.

[0025] This configuration provides the same effects as those described above for the phase characteristic measurement method, and also makes it possible to correct the phase characteristics of the high-frequency signal based on the phase characteristics of the high-frequency signal generating unit measured by the phase characteristic measurement method, thereby making it possible to generate a high-frequency signal with good phase characteristics.

[0026] To achieve the above object, a signal analysis method according to the present invention includes: a three-tone signal generation step of generating a three-tone signal using a reference signal generation unit; and a phase characteristic measurement method according to any one of the above methods, which measures the phase characteristic of the reference signal generation unit by measuring the phase characteristic of the three-tone signal generated in the three-tone signal generation step; a reference signal generation step of generating a reference signal using the reference signal generation unit; a reference signal analysis step of measuring the phase characteristic of the reference signal using a high-frequency signal analysis unit; and a high-frequency signal analysis step of analyzing an input signal using the high-frequency signal analysis unit, wherein the signal analysis method calculates the phase characteristic of the high-frequency signal analysis unit from the phase characteristic of the reference signal generation unit measured by the phase characteristic measurement method and the phase characteristic of the reference signal measured in the reference signal analysis step, corrects the phase characteristic when analyzing the input signal in the high-frequency signal analysis step based on the calculated phase characteristic of the high-frequency signal analysis unit, and performs signal analysis of the input signal with the corrected phase characteristic.

[0027] As described above, the phase characteristics of the reference signal generating section are measured by the phase characteristics measurement method, and the reference signal having known phase characteristics is analyzed in the high frequency signal analysis step to measure the phase characteristics of the high frequency signal analyzing section, and the phase characteristics are corrected when performing signal analysis of the input signal based on the measured phase characteristics of the high frequency signal analyzing section. This provides the same effects as those described above for the phase characteristics measurement method, and also makes it possible to perform signal analysis with corrected phase characteristics, thereby improving the quality of the analysis. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide a phase characteristic measuring device that can achieve phase measurement relatively inexpensively without increasing the scale of the device used for phase measurement, a signal generating device and a signal analyzing device that include the same, and a phase characteristic measuring method. [Brief explanation of the drawings]

[0029] [Figure 1]1 is a diagram showing a configuration of a phase characteristic measurement system using a detector according to an embodiment of the present invention; [Figure 2] FIG. 1 is a diagram showing the configuration of a phase characteristic measuring instrument (three-tone equal amplitude) according to an embodiment of the present invention. [Figure 3] 1 is a diagram showing the configuration of a phase characteristic measuring device (three-tone unequal amplitude) according to an embodiment of the present invention. [Figure 4] 1 is a diagram showing a schematic configuration of a signal generating device equipped with a phase characteristic measuring device according to an embodiment of the present invention; [Figure 5] 1 is a diagram showing a detailed configuration of a signal generating device equipped with a phase characteristic measuring device according to an embodiment of the present invention; [Figure 6] 1 is a diagram showing a schematic configuration of a signal analyzing device including a phase characteristic measuring device according to an embodiment of the present invention; [Figure 7] 1 is a diagram showing a detailed configuration of a signal analyzing device equipped with a phase characteristic measuring device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0031] First, the measurement principle of a phase characteristic measurement system using a detector used in an embodiment of the present invention will be described. FIG. 1 shows a schematic configuration of a phase characteristic measurement system 10 according to an embodiment of the present invention. First, a three-tone signal, which is a combination of three high-frequency waves (frequencies f1, f2, and f3), is input to a first detector 11. The frequencies of the tones in the three-tone signal are equally spaced (f2-f1=f3-f2). The first detector 11 performs square-law detection on the input three-tone signal and outputs a detection result with a frequency lower than the frequency of the three-tone signal. As a result, the first detector 11 generates a DC component proportional to the average power of the three-tone signal and beats between each of the tones. The beat frequency between the wave with frequency f1 and the wave with frequency f2 is f2-f1, the beat frequency between the wave with frequency f2 and the wave with frequency f3 is f3-f2, and the beat frequency between the wave with frequency f1 and the wave with frequency f3 is f3-f1. Therefore, the first detector 11 outputs a DC component, a frequency component with a frequency interval Δf (= f2 - f1 = f3 - f2) between adjacent waves, and a frequency component with a frequency interval 2Δf (= f3 - f1) between the waves at both ends. A bandpass filter (BPF) 12 removes the DC component and frequency components twice the tone interval Δf (= f2 - f1 = f3 - f2), allowing only the tone interval frequency components to pass. In other words, the BPF 12 extracts beat components at frequencies f2 - f1 and f3 - f2. The beat components output from the BPF 12 are input to the second detector 13. The second detector 13 performs square-law detection on the input beat components and outputs detection results for frequencies lower than the frequency of the beat components. Because the beat components input to the second detector 13 are sinusoidal waves with a constant amplitude, the second detector 13 outputs a DC voltage proportional to the power of the beat components. That is, the power of the signal that is the sum of the two beat components extracted by BPF 12 is detected by second detector 13, and its magnitude is measured by voltmeter 14. The phase of the beat component output from first detector 11 changes depending on the phase of the three-tone signal, but since the two beat components f2-f1 and f3-f2 have the same frequency, they interfere with each other, and the power of the beat component of frequency Δf changes depending on the phase of the beat components.The phase relationship (second-order differential value) of the three tones can be calculated using the formula described below by varying the phase of one of the tones in the three-tone signal and measuring the resulting change in the power of the beat component of frequency Δf with second detector 13 and voltmeter 14. The phase characteristics over any frequency range can be determined by step-sweeping the frequency of the three-tone signal.

[0032] As the second detector 13, not only a detector that outputs a voltage proportional to the power of the input signal but also a detector that outputs a voltage proportional to the logarithm of the power of the input signal can be used. When a detector with a logarithmic output is used, the output voltage of the detector is converted to the input power of the detector by the following equation (15). However, P in is the detector input power, V out is the detector output voltage, α is the detector sensitivity (unit: V / dB), P interc is the input power equivalent to zero output voltage (logarithmic intercept).

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[0033] (First embodiment) 2 and 3 are diagrams showing the configuration of a phase characteristic measuring instrument according to a first embodiment of the present invention. As shown in Fig. 2 and 3, the phase characteristic measuring instrument 1 of the first embodiment includes a first detector 11, a BPF 12, a second detector 13, a voltmeter 14, and a phase calculator 15.

[0034] Specifically, the first detector 11 receives a three-tone signal obtained by combining three high-frequency waves and detects the power of the three-tone signal. The BPF 12 passes, from the signal output from the first detector 11, a frequency component corresponding to the angular frequency difference Δω (=ω2-ω1=ω3-ω2) between adjacent waves of the three-tone signal, and blocks a frequency component twice the angular frequency difference Δω and a DC component. The first detector 11 may be implemented, for example, as a detector using a diode, and may have the characteristics of detecting the three-tone signal obtained by combining three waves e1, e2, and e3 and outputting a beat component of angular frequency Δω. The second detector 13 detects the power of the beat component that has passed through the BPF 12. The second detector 13 may be implemented, for example, as a detector using a diode, and may have the characteristics of detecting the tone interval angular frequency Δω of the three-tone signal. The voltmeter 14 measures the voltage of the signal output from the second detector 13. The voltmeter is only required to measure the voltage corresponding to the output of the detector 13. For example, one end of the voltmeter is connected to either the anode or cathode of a diode-based detector, and the other end is connected to a reference potential such as ground. As long as the reference potential is stable, the other end of the voltmeter does not necessarily have to be grounded. As will be explained later, the phase calculator 15 calculates the phase relationship and calculates the phase characteristics. The voltmeter 14 in the figure may also be an ammeter. The ammeter is only required to measure the current corresponding to the output of the detector 13. For example, one end of the ammeter is connected to either the anode or cathode of the diode-based detector. The other end of the ammeter may be connected to a reference potential, and a predetermined bias voltage may be applied to the diode. In addition, since the calculation formula described below calculates the ratio of the power of the beat components, it is sufficient to obtain a value proportional to the power of the signal that has passed through the BPF 12, and if the second detector 13 outputs a voltage or current proportional to the input power, the measured voltage value or current value may be used as is.

[0035] Here, we will explain the method for generating the three-tone signal input to the first detector 11 and the method for calculating the phase in the phase calculator 15. We will explain two methods: a simple method that can be used when all three tones have equal amplitude, and a method that can be used even when the amplitudes of the three tones are unknown and unequal.

[0036] <When all three tones have equal amplitude> First, the case where all three tones have the same amplitude will be described with reference to FIG.

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[0037] Only the beat component with angular frequency Δω is extracted from this signal by BPF12. The operator that extracts only the angular frequency Δω component by BPF12 is called BPF Δω If we define [ ], the beat component extracted by the BPF 12 is expressed as in the following equation (17).

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[0038] Therefore, the power of this beat component E beat is detected by the second detector 13 and measured by the voltmeter 14.

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[0039] Similarly, the second three-tone signal (pattern 2) obtained by multiplexing three waves e'1, e'2, and e'3 expressed by the following equation (19) is detected by the first detector 11. i ,φ i , i=1, 2, 3 are the ω i ,φ i ,i=1,2,3 is the same.

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[0040] The beat component extracted by BPF12 at this time is Δω [(e′1+e′2+e′3) 2 ] and its power E′ beat is detected by the second detector 13 and measured by the voltmeter 14.

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[0041] Therefore, the second derivative φ2″ of the phase at the angular frequency ω2 is expressed by the following equation (21), which is calculated by the phase calculator 15. The phase calculation method of equation (21) is as follows: beat / E beat is based on the division of E′ beat and E beat Since the result does not change even if we multiply by a constant, E′ beat and E beat may be a value proportional to the power of the beat component extracted by the BPF 12.

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[0042] By sweeping the frequency of the three-tone signal and finding the second-order differential value of the phase within the band to be measured using equation (21) above, the frequency characteristic of the phase can be found by integrating the second-order differential value of the phase twice using equation (22) below. This frequency characteristic of the phase is calculated, for example, by phase calculator 15. θ0 and θ0' in equation (22) are the initial phase and initial phase slope, and are arbitrary integration constants.

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[0043] Here, the sign of the argument in equation (21) is indefinite. In other words, it is difficult to distinguish between positive and negative values ​​in measurements where φ2″ is near zero. For this reason, a known phase difference is given to the three-tone signal (pattern 1) and the second three-tone signal (pattern 2), for example, φ2″Δω 2 =π / 2, 0<φ2″Δω 2 It is desirable to measure so that it is within the range of <π.

[0044] <When the amplitude of the three tones is unknown> Next, we will explain the case where the amplitudes of the three tones are unknown and unequal. In the above explanation, we considered the case where the amplitudes of the tone signals are all equal, but in reality, there is a frequency characteristic of the amplitude, and the amplitude of each tone signal is unknown and unequal.

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[0045] The three-tone signal obtained by combining the three-tone signals e1, e2(ψ), and e3 is detected by the first detector 11, and the component of the angular frequency Δω is extracted by the BPF 12. Δω [(e1+e2(ψ)+e3) 2 ] and its power is E beatThe output signal of the BPF 12 is detected by the second detector 13, and the output voltage of the detector 13 is measured by the voltmeter 14, which gives E beat (ψ) is obtained. In particular, when ψ=0,π / 2,π, we calculate the power as follows:

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[0046] From this result, the second derivative of the phase is

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[0047] Also, using the atan2 function,

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[0048] [atan2 function definition] atan2(y,x) is a function that returns the argument of a point (x,y) in the Cartesian coordinate system. The range of possible values ​​is -π <atan2≦πである。

[0049] FIG. 3 shows an example of the configuration of the phase characteristic measuring instrument 1 when the amplitudes of the three tones are unknown. As shown in FIG. 3, the first detector 11 receives three patterns (ψ=0, π / 2, π) of the three-tone signal obtained by combining three waves shown in the above equation (23), and detects the power of each of the three-tone signals. The BPF 12 passes the frequency component of the angular frequency difference Δω (=ω2-ω1=ω3-ω2) between adjacent waves of the three-tone signal, out of the signal output from the first detector 11, and cuts off the frequency component of twice the angular frequency difference Δω and the DC component. The second detector 13 and voltmeter 14 measure the power E of the beat component that has passed through the BPF 12. beatThe phase calculator 15 calculates the phase relationship (second-order differential value) shown by the above equation (25) or (26) to calculate the phase characteristics.

[0050] The phase characteristic measurement technology presented in this paper can be applied not only to devices that measure phase characteristics, but also to signal generators (SG) and signal analyzers (SA) that incorporate such devices, which is expected to improve the modulation and demodulation quality of wideband signals.

[0051] (Second embodiment) Next, a signal generating device equipped with a phase characteristic measuring device will be described.

[0052] Fig. 4 shows a schematic configuration of a signal generating device 100 equipped with a phase characteristic measuring device 1, and Fig. 5 shows a detailed configuration. As shown in Figs. 4 and 5, the signal generating device 100 is equipped with a phase characteristic measuring device 1, a high-frequency signal generating section 2, and a coupler 3. The phase characteristic of the high-frequency signal generating section 2 is corrected based on the phase characteristic of the high-frequency signal generating section 2 measured by the phase characteristic measuring device 1.

[0053] Specifically, the high-frequency signal generating unit 2 includes a signal source 21, a frequency conversion unit 22, and a local oscillator signal generating unit 23, and uses the local oscillator signal generating unit 23, which generates a CW local oscillator signal, and the frequency conversion unit 22, such as a mixer, to frequency convert (upconvert) the signal generated by the signal source 21 to a frequency in the high-frequency band and output the high-frequency signal. The coupler 3 branches the high-frequency signal output from the high-frequency signal generating unit 2, and outputs one signal as an output signal and the other signal to the phase characteristic measuring device 1. The phase characteristic measuring device 1 receives the high-frequency signal branched by the coupler 3 and measures the phase characteristic of the input signal.

[0054] In detail, as shown in FIG. 5, the high-frequency signal generating unit 2 includes intermediate frequency signal generators 24a to 24c, an adder 25, a switch 26, a frequency conversion unit 22, a local oscillator signal generating unit 23, a waveform memory 27, and a D / A converter 28.

[0055] When switch 26 is set to contact A, high-frequency signal generating unit 2 adds (combines) sine wave intermediate frequency signals generated by intermediate frequency signal generators 24a to 24c in adder 25, and then frequency converts (up-converts) the result in frequency conversion unit 22, outputting it as a high-frequency band three-tone signal. A portion of the three-tone signal output from high-frequency signal generating unit 2 is sent to phase characteristic measuring instrument 1 via coupler 3, and the phase characteristic of high-frequency signal generating unit 2 is measured.

[0056] The waveform memory 27 stores the signal generated by the high-frequency signal generator 2, which has been generated in advance by digital calculation. When the switch is set to contact B, the data in the waveform memory 27 is input to the D / A converter 28 and converted into an analog signal, and then frequency converted (up-converted) by the frequency converter 22 and output as a high-frequency signal. At this time, by applying the inverse of the phase characteristics of the high-frequency signal generator 2, which have been measured in advance, to the waveform memory 27 of the high-frequency signal generator 2, a high-frequency signal with corrected phase characteristics is output, thereby improving the modulation quality of the high-frequency signal generator 2. In FIG. 5, the inverse of the phase characteristics is applied to the signal recorded in the waveform memory 27, but the phase characteristics can also be corrected by applying a filter with the inverse phase characteristics to the digital signal output from the waveform memory 27.

[0057] Since this signal generator 100 can output a signal with corrected phase characteristics, it can be used as a reference signal for correcting the phase characteristics of an external high-frequency signal receiver, etc. In this case, the switch 26 may be set to contact A to output a three-tone signal, or to contact B to output a wideband signal (e.g., a multi-tone signal with three or more tones). When the switch 26 is set to contact A, the inverse of the phase characteristics of the high-frequency signal generator 2 measured by the phase characteristics measurement device 1 is set as the initial phase of the intermediate frequency signal generators 24a to 24c. When the switch 26 is set to contact B, the inverse of the phase characteristics of the high-frequency signal generator 2 measured by the phase characteristics measurement device 1 is applied to the waveform memory 27 to output a wideband signal with corrected phase characteristics. Note that the coupler 3 may also be a switch, for example. When the coupler 3 is replaced with a second switch, when the second switch is set to send a signal to the phase characteristics measurement device 1, a calibration operation is performed, whereas when the second switch is set to the output side, the switch 26 can be set to contact B and a signal generation operation is performed.

[0058] (Third embodiment) Next, a signal analysis device equipped with a phase characteristic measuring device will be described.

[0059] Fig. 6 shows a schematic configuration of a signal analyzing device 200 equipped with a phase characteristic measuring device 1, and Fig. 7 shows a detailed configuration. As shown in Figs. 6 and 7, the signal analyzing device 200 includes the phase characteristic measuring device 1, a reference signal generating unit 20, a coupler 3, a switch 4, and a high-frequency signal analyzing unit 5. The phase characteristic of the reference signal generating unit 20 is measured by the phase characteristic measuring device 1, and a reference signal having a known phase characteristic is input from the reference signal generating unit 20 to the high-frequency signal analyzing unit 5, thereby measuring the phase characteristic of the high-frequency signal analyzing unit 5, and correcting the phase characteristic of the high-frequency signal analyzing unit 5 based on the measured phase characteristic. Then, signal analysis of the input signal is performed by the high-frequency signal analyzing unit 5 with the phase characteristic corrected.

[0060] Specifically, reference signal generating unit 20 includes signal source 21, frequency conversion unit 22, and local oscillator signal generating unit 23. Using local oscillator signal generating unit 23, which generates a CW local oscillator signal, and frequency conversion unit 22, such as a mixer, the signal generated by signal source 21 is frequency converted (up-converted) to a high-frequency band frequency and outputs a reference signal. Coupler 3 branches the reference signal output from reference signal generating unit 20 and outputs one signal to phase characteristic measuring unit 1, and switch 4 sends the other signal branched by coupler 3 to high-frequency signal analyzing unit 5. Phase characteristic measuring unit 1 receives the reference signal branched by coupler 3 and measures the phase characteristic of the input signal. Switch 4 selects either the other signal of the reference signal branched by coupler 3 or the input signal. The high-frequency signal analysis unit 5 includes a frequency conversion unit 51, a local signal generation unit 52, and a signal processing unit 53, and the signal selected by the switch 4 is frequency converted (down-converted) by the frequency conversion unit 51 and the local signal generation unit 52, and the signal is analyzed by the signal processing unit 53.

[0061] 7, the reference signal generating unit 20 includes intermediate frequency signal generators 24a to 24c, an adder 25, a frequency conversion unit 22, and a local oscillator signal generating unit 23. The high frequency signal analyzing unit 5 includes a frequency conversion unit 51, a local oscillator signal generating unit 52, an A / D converter 54, a phase response correcting unit 55, a waveform memory 56, a second switch 57, a reference signal phase measuring unit 58, and a phase response correcting value calculating unit 59.

[0062] First, the phase characteristic of reference signal generating section 20 is measured by phase characteristic measuring instrument 1. Specifically, reference signal generating section 20 adds (combines) sine wave intermediate frequency signals generated by intermediate frequency signal generators 24a to 24c in adder 25, and frequency converts (up-converts) the signals in the frequency conversion section 22 to output them as a high frequency band three-tone signal. A portion of the three-tone signal output from reference signal generating section 20 is sent to phase characteristic measuring instrument 1 via coupler 3, and the phase characteristic of reference signal generating section 20 is measured.

[0063] Next, switch 4 is set to contact A, and second switch 57 is set to contact B. A wideband signal with known phase characteristics (a three-tone signal is shown in FIG. 7 , but a multi-tone signal with four or more frequencies may also be used) from reference signal generator 20 is input as a reference signal to high-frequency signal analyzer 5, and the phase characteristics of high-frequency signal analyzer 5 are measured. Specifically, the reference signal sent from reference signal generator 20 via switch 4 is frequency-converted (down-converted) by frequency converter 51 and local oscillator signal generator 52 in high-frequency signal analyzer 5, converted to a digital signal by A / D converter 54, and sent via second switch 57 to reference signal phase measurer 58, where the phase characteristics of the reference signal are measured. In FIG. 7 , the reference signal is a three-tone signal. The phase characteristics of the reference signal can be obtained by calculating the second-order differential value of the phase of the frequency-converted and digitalized three-tone signal, sweeping the frequency of the three-tone signal, and integrating the second-order differential value twice. When the reference signal is a multi-tone signal with four or more waves, the second-order differential values ​​of the phase at multiple frequencies can be obtained at one time, making it possible to obtain the phase characteristics of the reference signal with a small number of frequency sweep points. The phase response correction value calculation unit 59 calculates the phase characteristics of the high-frequency signal analysis unit 5 from the phase characteristics of the reference signal measured by the reference signal phase measurement unit 58 and the phase characteristics of the reference signal generation unit 20 measured by the phase characteristics measurement instrument 1. In other words, the phase characteristics of the high-frequency signal analysis unit 5 are obtained by subtracting the phase characteristics of the reference signal generation unit 20 measured by the phase characteristics measurement instrument 1 from the phase characteristics of the reference signal measured by the reference signal phase measurement unit 58. Here, the phase characteristics of the high frequency signal analyzing unit 5 are calculated from the phase characteristics of the reference signal measured by the reference signal phase measuring unit 58 and the phase characteristics of the reference signal generating unit 20 measured by the phase characteristics measuring instrument 1, but the phase of the reference signal generated by the reference signal generating unit 20 may be corrected by setting the inverse characteristics of the phase characteristics of the reference signal generating unit 20 measured by the phase characteristics measuring instrument 1 as the initial phase of the intermediate frequency signal generators 24a to 24c. In this case, the reference signal whose phase characteristics have been corrected is input to the high frequency signal analyzing unit 5, and therefore the phase characteristics of the reference signal measured by the reference signal phase measuring unit 58 become the phase characteristics of the high frequency signal analyzing unit 5.

[0064] When switch 4 is set to contact B and second switch 57 is set to contact A, the input signal is frequency converted (down-converted) by frequency conversion section 51 and local oscillator signal generation section 52, converted to a digital signal by A / D converter 54, the phase characteristics of high frequency signal analysis section 5 are corrected by phase response correction section 55, the signal is stored in waveform memory 56, and output as analysis data. In other words, by applying to phase response correction section 55 a digital filter having the inverse characteristics of the phase characteristics of high frequency signal analysis section 5 calculated earlier by phase response correction value calculation section 59, signal analysis is performed with the phase characteristics of high frequency signal analysis section 5 corrected, and the analysis quality (demodulation quality) can be improved.

[0065] 7, the phase characteristics are corrected by applying a digital filter having the inverse characteristics of the phase characteristics of the high frequency signal analysis unit 5 to the digital signal output from the A / D converter 54, but the phase characteristics may also be corrected by temporarily storing the digital signal output from the A / D converter 54 in a waveform memory 56 and then applying the inverse characteristics of the phase characteristics to the waveform data in the waveform memory 56 through offline processing. Also, the coupler 3 in the figure may be, for example, a switch, and the switch 4 may be, for example, a coupler. [Industrial Applicability]

[0066] As described above, the present invention has the effect of avoiding the need for large-scale equipment for phase measurement and enabling phase measurement to be achieved relatively inexpensively by using a voltmeter or detector that does not require high-speed triggering, and is useful for phase characteristic measuring instruments, signal generators and signal analyzers that include such instruments, and phase characteristic measuring methods in general. [Explanation of symbols]

[0067] 1 Phase characteristic measuring instrument 10 Phase characteristic measurement system 11 First detector 12 Bandpass Filter (BPF) 13 Second detector 14 Voltmeter 15 Phase Calculator 2 High frequency signal generator 20 Reference signal generator 21 Signal source 22 Frequency conversion section 23 Local signal generator 24a, 24b, 24c Intermediate frequency signal generator 25 Adder 26 Switch 27 Waveform Memory 28 D / A converter 3 Coupler 4 Switch 5 High frequency signal analysis section 51 Frequency conversion unit 52 Local signal generator 53 Signal Processing Unit 54 A / D converter 55 Phase response correction unit 56 waveform memories 57 Second Switch 58 Reference signal phase measurement section 59 Phase response correction value calculation unit 100 Signal Generator 200 Signal analysis equipment

Claims

1. The three waves e are expressed by the following equation (1): １ , e ２ , e ３ and a three-tone signal e′ expressed by the following equation (2): １ , e' ２ , e' ３ a first detector (11) for receiving and detecting the second three-tone signal obtained by combining the first and second three-tone signals; a bandpass filter (12) that passes frequency components of the first and second three-tone signals whose frequencies are the angular frequency difference Δω between adjacent waves, and blocks frequency components that are twice the angular frequency difference Δω and DC components, among the signals output from the first detector; a second detector (13) for detecting a signal that has passed through the bandpass filter; a voltmeter (14) for measuring the voltage of the signal output from the second detector; The phase φ is expressed by the following equation (3): ２ a phase calculator (15) for calculating "; A phase characteristic measuring instrument equipped with [Equation 1] (However, ω ｉ is the angular frequency, φ ｉ represents the phase, t represents the time, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [Equation 2] [Equation 3] (However, E ｂｅａｔ represents a value proportional to the power of the signal passed through the band-pass filter, which is obtained from the voltage value measured by the voltmeter when the first detector receives the first three-tone signal, and E' ｂｅａｔ represents a value proportional to the power of the signal that has passed through the band-pass filter, which is obtained from the voltage value measured by the voltmeter when the first detector receives the second three-tone signal.

2. The three waves e are expressed by the following equation (4): １ , e ２ , e ３ a first detector (11) for receiving and detecting a three-tone signal obtained by combining the above; a bandpass filter (12) that passes a frequency component of the three-tone signal output from the first detector that corresponds to the angular frequency difference Δω between adjacent waves, and blocks a frequency component that is twice the angular frequency difference Δω and a DC component; a second detector (13) for detecting a signal that has passed through the bandpass filter; a voltmeter (14) for measuring the voltage of the signal output from the second detector; The phase φ expressed by the following equation (5) ２ a phase calculator (15) for calculating "; A phase characteristic measuring instrument equipped with [Equation 4] (However, a １ , a ２ , a ３ is the amplitude, ω １ , ω ２ , ω ３ is the angular frequency, φ １ , φ ２ , φ ３ , ψ represents the phase, t represents the time, ψ=0, π / 2, π, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [Equation 5] (However, E ｂｅａｔ (0) represents a value proportional to the power of the signal that has passed through the band-pass filter and is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ=0, and E ｂｅａｔ (π / 2) represents a value proportional to the power of the signal that has passed through the band-pass filter and is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ=π / 2, and E ｂｅａｔ (π) represents a value proportional to the power of the signal that has passed through the band-pass filter, which is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ = π.

3. The three waves e expressed by the following equation (6) １ , e ２ , e ３ a first detector (11) for receiving and detecting a three-tone signal obtained by combining the above; a bandpass filter (12) that passes a frequency component of the three-tone signal output from the first detector that corresponds to the angular frequency difference Δω between adjacent waves, and blocks a frequency component that is twice the angular frequency difference Δω and a DC component; a second detector (13) for detecting a signal that has passed through the bandpass filter; a voltmeter (14) for measuring the voltage of the signal output from the second detector; The phase φ expressed by the following equation (7) ２ a phase calculator (15) for calculating "; A phase characteristic measuring instrument equipped with [Equation 6] (However, a １ , a ２ , a ３ is the amplitude, ω １ , ω ２ , ω ３ is the angular frequency, φ １ , φ ２ , φ ３ , ψ represents the phase, t represents the time, ψ=0, π / 2, π, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [Equation 7] (However, E ｂｅａｔ (0) represents a value proportional to the power of the signal that has passed through the band-pass filter and is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ=0, and E ｂｅａｔ (π / 2) represents a value proportional to the power of the signal that has passed through the band-pass filter and is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ=π / 2, and E ｂｅａｔ (π) represents a value proportional to the power of the signal that has passed through the band-pass filter, which is obtained from the voltage value measured by the voltmeter when the first detector receives the three-tone signal when ψ = π.

4. a high frequency signal generating unit (2) for generating a high frequency signal and a three-tone signal; a coupler (3) that branches the signal output from the high-frequency signal generating unit and outputs one of the branches as an output signal; a phase characteristic measuring device (1) according to any one of claims 1 to 3, wherein when the high frequency signal generating unit generates the three-tone signal, the other signal branched by the coupler is input, and the phase of the input three-tone signal is measured to measure the phase characteristic of the high frequency signal generating unit; and when the high frequency signal generating unit generates the high frequency signal, the phase characteristic of the high frequency signal is corrected based on the phase characteristic of the high frequency signal generating unit measured by the phase characteristic measuring device.

5. a reference signal generating section (20) for generating a reference signal and a three-tone signal; a coupler (3) that branches the signal output from the reference signal generating unit; a phase characteristic measuring device (1) according to any one of claims 1 to 3, wherein when the reference signal generating unit generates the three-tone signal, one of the signals branched by the coupler is input, and the phase of the input three-tone signal is measured to measure the phase characteristic of the reference signal generating unit; a switch (4) for selecting either the other signal branched by the coupler or the input signal; a high frequency signal analysis unit (5) that analyzes the signal selected by the switch; when the reference signal generating unit generates the reference signal and the other signal branched by the coupler is selected by the switch, the phase characteristic of the high frequency signal analyzing unit is calculated from the phase characteristic of the reference signal measured by the high frequency signal analyzing unit and the phase characteristic of the reference signal generating unit measured by the phase characteristic measuring device, and when the input signal is selected by the switch, the phase characteristic when the high frequency signal analyzing unit analyzes the input signal is corrected based on the calculated phase characteristic of the high frequency signal analyzing unit, and signal analysis of the input signal with the corrected phase characteristic is performed.

6. The three waves e are expressed by the following equation (8): １ , e ２ , e ３ a first three-tone signal generating step of generating a first three-tone signal by combining the above; a first detection step of detecting the first three-tone signal; a first band-pass filter step of passing a frequency component of the first three-tone signal having a frequency equal to the angular frequency difference Δω between adjacent waves, and cutting off a frequency component twice the angular frequency difference Δω and a DC component, from the signal obtained by the first detection step; a second detection step of detecting the signal passed through the first band-pass filtering step; a first voltage measurement step of measuring a voltage of the signal obtained by the second detection step; Three waves e' expressed by the following equation (9) １ , e' ２ , e' ３ a second three-tone signal generating step of generating a second three-tone signal by combining the above; a third detection step of detecting the second three-tone signal; a second band-pass filtering step of passing a frequency component of the second three-tone signal having a frequency equal to the angular frequency difference Δω between adjacent waves of the second three-tone signal and blocking a frequency component twice the angular frequency difference Δω and a DC component from the signal obtained by the third detection step; a fourth detection step of detecting the signal passed through the second band-pass filtering step; a second voltage measurement step of measuring a voltage of the signal obtained by the fourth detection step; A phase φ expressed by the following equation (10) is calculated from the voltage value measured in the first voltage measurement step and the voltage value measured in the second voltage measurement step. ２ a phase calculation step for calculating " A phase characteristic measuring method including: [Equation 8] (However, ω ｉ is the angular frequency, φ ｉ represents the phase, t represents the time, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [Equation 9] [Equation 10] (However, E ｂｅａｔ represents a value proportional to the power of the signal passed through the first band-pass filter step, which is obtained from the voltage value measured in the first voltage measurement step, and E' ｂｅａｔ represents a value proportional to the power of the signal passed through the second band-pass filtering step, which is obtained from the voltage value measured in the second voltage measuring step.

7. The three waves e are expressed by the following equation (11): １ , e ２ , e ３ a three-tone signal generating step of generating a three-tone signal by combining the above; a first detection step of detecting the three-tone signal; a band-pass filter step of passing a frequency component of the three-tone signal obtained by the first detection step, the frequency of which is the angular frequency difference Δω between adjacent waves, and cutting off a frequency component of twice the angular frequency difference Δω and a DC component; a second detection step of detecting the signal passed through the band-pass filtering step; a voltage measuring step of measuring a voltage of the signal obtained by the second detection step; The phase ψ of the following equation (11) is set to 0, π / 2, and π, and the phase φ expressed by the following equation (12) is calculated from each voltage value measured by executing the three-tone signal generating step, the first detection step, the band-pass filter step, the second detection step, and the voltage measuring step. ２ a phase calculation step for calculating " A phase characteristic measuring method including: [0011] (However, a １ , a ２ , a ３ is the amplitude, ω １ , ω ２ , ω ３ is the angular frequency, φ １ , φ ２ , φ ３ , ψ represents the phase, t represents the time, ψ=0, π / 2, π, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [0012] (However, E ｂｅａｔ (0) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=0, and E ｂｅａｔ (π / 2) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=π / 2, and E ｂｅａｔ (π) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=π.

8. The three waves e expressed by the following equation (13) １ , e ２ , e ３ a three-tone signal generating step of generating a three-tone signal by combining the above; a first detection step of detecting the three-tone signal; a band-pass filter step of passing a frequency component of the three-tone signal obtained by the first detection step, the frequency of which is the angular frequency difference Δω between adjacent waves, and cutting off a frequency component of twice the angular frequency difference Δω and a DC component; a second detection step of detecting the signal passed through the band-pass filtering step; a voltage measuring step of measuring a voltage of the signal obtained by the second detection step; The phase ψ of the following equation (13) is set to 0, π / 2, and π, and the phase φ expressed by the following equation (14) is calculated from the voltage values ​​measured by executing the three-tone signal generating step, the first detection step, the band-pass filter step, the second detection step, and the voltage measuring step. ２ a phase calculation step for calculating " A phase characteristic measuring method including: [0013] (However, a １ , a ２ , a ３ is the amplitude, ω １ , ω ２ , ω ３ is the angular frequency, φ １ , φ ２ , φ ３ , ψ represents the phase, t represents the time, ψ=0, π / 2, π, and ω ２ -ω １ =ω ３ -ω ２ = Δω.) [0014] (However, E ｂｅａｔ (0) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=0, and E ｂｅａｔ (π / 2) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=π / 2, and E ｂｅａｔ (π) represents a value proportional to the power of the signal passed through the band-pass filter step, which is obtained from the voltage value measured in the voltage measurement step when ψ=π.

9. a three-tone signal generating step of generating a three-tone signal using a high-frequency signal generating unit; a phase characteristic measuring method according to any one of claims 6 to 8, wherein the phase characteristic of the high frequency signal generating unit is measured by measuring the phase of the three-tone signal generated in the three-tone signal generating step; a high-frequency signal generating step of generating a high-frequency signal using the high-frequency signal generating unit and outputting the generated high-frequency signal as an output signal; and correcting the phase characteristic of the high frequency signal based on the phase characteristic of the high frequency signal generating unit measured by the phase characteristic measuring method.

10. a three-tone signal generating step of generating a three-tone signal using a reference signal generating unit; a phase characteristic measuring method according to any one of claims 6 to 8, wherein the phase characteristic of the reference signal generating unit is measured by measuring the phase characteristic of the three-tone signal generated in the three-tone signal generating step; a reference signal generating step of generating a reference signal using the reference signal generating unit; a reference signal analysis step of measuring a phase characteristic of the reference signal using a high frequency signal analysis unit; a high frequency signal analysis step of analyzing an input signal using the high frequency signal analysis unit; a phase characteristic of the high frequency signal analysis unit is calculated from the phase characteristic of the reference signal generating unit measured by the phase characteristic measurement method and the phase characteristic of the reference signal measured by the reference signal analysis step, and the phase characteristic is corrected when analyzing the input signal by the high frequency signal analysis step based on the calculated phase characteristic of the high frequency signal analysis unit, and signal analysis of the input signal with the corrected phase characteristic is performed.

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