JP5070787B2 - Surface acoustic wave measuring apparatus and method - Google Patents

Description

  The present invention relates to a surface acoustic wave measuring apparatus and method that can accurately measure a phase difference between an excitation signal and a circular signal.

  In recent years, “spherical surface acoustic wave devices” in which interdigital electrodes are formed on the surface of a spherical piezoelectric crystal substrate have been applied to various sensors.

  In the spherical surface acoustic wave element, when a high frequency signal is applied to the interdigital electrode, a surface acoustic wave is excited on the propagation surface on the surface of the substrate. In addition, the excited surface acoustic wave makes multiple rounds on the annular propagation surface because the spherical surface acoustic wave element has a spherical shape instead of a flat plate shape.

  The propagation speed of the surface acoustic wave that circulates multiple times varies depending on the state of the substrate surface. For example, the propagation speed of surface acoustic waves changes due to adhesion of molecules to the surface of the substrate. Further, when the circumference of the annular region is an integral multiple of the surface acoustic wave wavelength, the resonance frequency changes.

Then, development of the sensor which detects the molecule | numerator etc. which adhere to the reaction film formed into the base-material surface based on such a change of propagation speed is examined (for example, refer patent document 1).
JP 2005-101974 A

  However, in order to measure the change in the propagation velocity, it is necessary to measure the phase difference between the excitation signal for exciting the surface acoustic wave and the circulation signal detected after the surface acoustic wave makes multiple rounds of the element. .

  However, the phase is a value that varies between 0 and 2π. Therefore, when the phase changes beyond 2π, it is measured as if it is advanced even if the phase is delayed, making it difficult to accurately grasp the phase difference between the two signals.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a surface acoustic wave measurement apparatus and method that can accurately measure the phase difference between an excitation signal and a circulation signal.

  The present invention takes the following means in order to solve the above problems.

The invention corresponding to claim 1 is a surface acoustic wave that applies an excitation signal to an electrode of a spherical surface acoustic wave element and measures a vibration change of the surface acoustic wave from a circular signal of the surface acoustic wave excited by the excitation signal. In the measurement apparatus, the detection device includes a detection unit for detecting a surface acoustic wave based on the excitation signal and the circulation signal, and a measurement unit that measures a vibration change of the surface acoustic wave detected by the detection unit , A detecting means for generating a first reference signal having a frequency different from that of the excitation signal; a first signal generating means for generating a signal having a plurality of frequency components based on the circular signal and the first reference signal; A first extraction means for extracting a signal having a predetermined intermediate frequency component from the generated signal, and a first amplification means for amplifying the extracted signal, wherein the measurement means is based on the amplified signal. A phase information signal, a second signal generating means for generating a plurality of frequency component signals based on the excitation signal and the first reference signal, and a signal generated by the second signal generating means. Second extraction means for extracting a signal having a predetermined intermediate frequency component; second amplification means for amplifying the signal extracted by the second extraction means to generate a second reference signal; and the generated phase information signal A surface acoustic wave measuring device comprising: means for generating a plurality of phase comparison signals based on the second reference signal; and means for measuring a phase difference between the generated phase comparison signals .

The invention corresponding to claim 2 is the surface acoustic wave measuring device corresponding to claim 1, wherein the measuring means is based on the signal amplified by the first amplifying means and based on the amplitude component of the surface acoustic wave. Is a surface acoustic wave measuring device provided with means for demodulating the signal and means for measuring the demodulated amplitude component .

The invention corresponding to claim 3 is a surface acoustic wave that applies an excitation signal to an electrode of a spherical surface acoustic wave element and measures a vibration change of the surface acoustic wave from a circular signal of the surface acoustic wave excited by the excitation signal. In the measurement method, a detection step for detecting a surface acoustic wave based on the excitation signal and the circular signal, and a measurement step for measuring a vibration change of the surface acoustic wave detected by the detection step, The detection step includes a step of generating a first reference signal having a frequency different from that of the excitation signal, and a first signal generation step of generating a signal having a plurality of frequency components based on the circular signal and the first reference signal, A first extraction step of extracting a signal of a predetermined intermediate frequency component from the generated signal; and a first amplification step of amplifying the extracted signal, A step of generating a phase information signal based on the amplified signal; a second signal generating step of generating a signal of a plurality of frequency components based on the excitation signal and the first reference signal; A second extraction step for extracting a signal of a predetermined intermediate frequency component from the signals generated in the two-signal generation step; and a second amplification for amplifying the signal extracted in the second extraction step to generate a second reference signal A surface comprising: a step; generating a plurality of phase comparison signals based on the generated phase information signal and the second reference signal; and measuring a phase difference between the generated phase comparison signals This is an elastic wave measurement method.

The invention corresponding to claim 4 is the surface acoustic wave measurement method corresponding to claim 3, wherein the measurement step includes the amplitude component of the surface acoustic wave based on the signal amplified by the first amplification step. Is a surface acoustic wave measuring method comprising: a step of demodulating the signal; and a step of measuring the demodulated amplitude component .

<Action>
Therefore, the present invention has the following effects by taking the above-described means.

The invention corresponding to claims 1 and 3 generates a first reference signal having a frequency different from that of the excitation signal based on the excitation signal for exciting the surface acoustic wave and the circular signal from the surface acoustic wave , Based on the rounded signal and the first reference signal, a signal having a plurality of frequency components is generated, a signal having a predetermined intermediate frequency component is extracted from the generated signals, the extracted signal is amplified, and the signal is amplified. To generate a phase information signal, generate a signal of a plurality of frequency components based on the excitation signal and the first reference signal, extract a signal of a predetermined intermediate frequency component from the generated signals, and amplify the extracted signal The second reference signal is generated, a plurality of phase comparison signals are generated based on the generated phase information signal and the second reference signal, and the phase difference between the generated phase comparison signals is measured. And the phase difference between the loop signal and It can be measured in probability.

Since the invention corresponding to claims 2 and 4 demodulates the amplitude component of the surface acoustic wave and measures the demodulated amplitude component based on the amplified signal in addition to the operation corresponding to claims 1 and 3 , The phase difference between the excitation signal and the circular signal and the amplitude of the surface acoustic wave can be accurately measured.

  According to the present invention, the phase difference between the excitation signal and the circulation signal can be accurately measured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First Embodiment>
(1-1. Configuration)
FIG. 1 is a schematic diagram showing a configuration of a surface acoustic wave measurement apparatus 10 according to the first embodiment of the present invention.

  The surface acoustic wave measuring device 10 applies an excitation signal to the interdigital electrode 92 of the spherical surface acoustic wave element 90, and measures the vibration change of the surface acoustic wave from the circular signal of the surface acoustic wave excited by the excitation signal. It is.

  Specifically, the surface acoustic wave measuring device 10 includes a high frequency signal oscillating unit 11, a high frequency signal coupler 12, a high frequency switch unit 13, a high frequency amplifier unit 14, a high frequency power switch unit 15, a changeover switch unit 16, a matching unit 17, Control unit 18, preamplifier unit 20, circular signal distributor 21, reference signal distributor 22, phase shifter 23, I system multiplier circuit unit 24, Q system multiplier circuit unit 25, low pass filter unit 26, 27, DC amplifier unit 28, 29 and the measurement part 30 are provided.

  As shown in FIG. 2, the spherical surface acoustic wave element 90 includes a base 91 having a propagation surface 91S through which surface acoustic waves can propagate so as to be able to circulate, and an interdigital electrode 92 on the base 91. ing. The interdigital electrode 92 has a function of exciting a surface acoustic wave on the propagation surface 91S and detecting a circulating signal of the circulating surface acoustic wave.

  The high frequency signal oscillating unit 11 generates a high frequency signal (frequency fp) for generating surface acoustic wave vibration that circulates around the base material surface of the spherical surface acoustic wave element 90. The high frequency signal generated by the high frequency signal oscillating unit 11 is output to the high frequency switch unit 13 as an “excitation signal”. However, a part of the high frequency signal is output to the reference signal distributor 22 by the high frequency signal coupler 12.

  The high frequency switch unit 13 is a switch having high isolation characteristics, and is controlled by the control unit 18. The high-frequency signal input to the high-frequency switch unit 13 is amplified to a necessary high-frequency energy level by the high-frequency amplifier unit 14 and then sent to the changeover switch unit 16 via the high-frequency power switch unit 15. Since the high frequency switch unit 13 and the high frequency power switch unit 15 have high isolation characteristics, the high frequency switch unit 13 and the high frequency power switch unit 15 output a high frequency signal containing almost no leakage signal component from the high frequency signal oscillation unit 11.

  The high frequency power switch unit 15 is a switch having a high isolation characteristic, and has durability against a high energy output of a high frequency signal amplified by the high frequency amplification unit 14.

  The changeover switch unit 16 is a switch for switching whether an excitation signal is input to the interdigital electrode 92 of the spherical surface acoustic wave element 90 or a circular signal output from the interdigital electrode 92 is detected. Specifically, the changeover switch unit 16 connects the matching unit 17 and the high frequency power switch unit 15 (FIG. 3A), or connects the matching unit 17 and the preamplifier unit 20 (FIG. 3B). )), And the matching unit 17 has a function of switching to the state of not being connected to either the high-frequency power switch unit 15 or the preamplifier unit 20 (FIG. 3C). The matching unit 17 is connected to the high frequency power switch unit 15 (FIG. 3A), and after the surface acoustic wave is excited, the matching unit 17 is not connected to either the high frequency power switch unit 15 or the preamplifier unit 20. By doing so (FIG. 3C), the surface acoustic wave continues to circulate around the propagation surface 91S.

  The matching unit 17 is for performing impedance matching with the input impedance of the spherical surface acoustic wave element 90.

  The control unit 18 controls the operation of each device. Specifically, a control signal is output to perform control for simultaneously switching the high-frequency switch unit 13, the high-frequency power switch unit 15, and the changeover switch unit 16. As a result, the continuous wave output from the high-frequency signal oscillator 11 can be turned on and off, and a high-frequency burst signal can be applied to the spherical surface acoustic wave element 90.

  The preamplifier unit 20 amplifies the electrical signal (frequency fr) output from the spherical surface acoustic wave element 90 and outputs the amplified electrical signal to the circulation signal distributor 21 as a “circulation signal”.

  The circulation signal distributor 21 equally distributes the circulation signal sent from the preamplifier unit 20 into the “first circulation signal” and the “second circulation signal” having the same phase as each other. The signal is sent to the I system multiplication circuit unit 24 and the second circulation signal is sent to the Q system multiplication circuit unit 25.

  The reference signal distributor 22 equally distributes the high frequency signal transmitted from the high frequency signal coupler 12 to two reference signals having the same phase. Then, the reference signal distributor 22 transmits one of the two reference signals as a “first reference signal” to the I-system multiplication circuit unit 24 as it is. The other reference signal is sent to the phase shifter 23.

  The phase shifter 23 converts one phase of the equally distributed reference signal, and has a function of generating a “second reference signal” having a phase orthogonal to the phase of the first reference signal. That is, the second reference signal is obtained by shifting only the phase of the first reference signal by 90 °. As a method for shifting the phase by 90 °, a delay method using a transmission line can be used. Further, it is also possible to use a method in which a distributor and a phase shifter are integrated and a coil and a capacitor are combined so that an output signal having the same level can be obtained at each output terminal with a phase difference of 90 °. The second reference signal generated by the phase shifter 23 is output to the Q system multiplier circuit unit 25.

  The I-system multiplication circuit unit 24 outputs an “I signal” based on the first circulation signal input from the circulation signal distributor 21 and the first reference signal input from the reference signal distributor 22. It is. Specifically, it is configured by a non-linear element such as a diode or DBM (double balanced mixer).

  Here, the input / output characteristics of the I-system multiplication circuit unit 24 are non-linear. Therefore, the following expression is established for the input signal ein and the output signal eout. K1, K2, and K3 are constants.

^{eout = K1ein + K2ein 2 + K3ein} 3 + ·····
From this equation, in the I-system multiplication circuit unit 24, the reference signal is A ₀ cos (ωt), the circulation signal from the spherical surface acoustic wave element 90 is A _R cos (ωt + θ), and the sum of the reference signal and the circulation signal is obtained. Is substituted into the input signal ein, and each component is generated from the first-order term. The signal of a respective second harmonic component and the DC component by the phase difference _{θ K2 · A 0 · A R} cos (θ) is outputted from the second-order terms. In addition, the third and subsequent terms can be ignored because the output is small.

  The electrical signal output from the I-system multiplication circuit unit 24 is frequency-selected by the low-pass filter unit 26, amplified by the DC amplifier 28, and output to the measurement unit 30 as an I signal.

The Q system multiplication circuit unit 25 is for outputting a “Q signal” based on the second circulation signal input from the circulation signal distributor 21 and the second reference signal input from the phase shifter 23. . The Q system multiplier circuit unit 25 calculates the phase of the reference signal by 90 ° in the I system multiplier circuit unit 24, and its output signal is K2 · A ₀ · A _R sin (θ).

  The electrical signal output from the Q system multiplication circuit unit 25 is frequency-selected by the low-pass filter unit 27, amplified by the DC amplifier 29, and output to the measuring unit 30 as a Q signal.

  The low-pass filter units 26 and 27 are filters that allow a direct current component to pass therethrough but block a signal having a frequency equal to or higher than that of the reference signal.

  The measuring unit 30 measures the vibration change of the surface acoustic wave based on the I signal and the Q signal sent from the DC amplifiers 28 and 29.

Here, if the phase difference between the reference signal and the circulating signal is θ, the I signal (S _I ) and the Q signal (S _Q ) are respectively expressed as follows.

S _I = K2 · A ₀ · A _R cos (θ)
S _Q = K2 · A ₀ · A _R sin (θ)
Therefore, when the I signal and the Q signal are each represented by orthogonal coordinates, they are represented by circumferential points as shown in FIG. This makes it possible to measure phase advance and delay on two-dimensional coordinates.

  Further, as shown in FIG. 5, the change in the amplitude of the surface acoustic wave can be measured by examining the attenuation rate of the circulating signal R2 corresponding to the next burst signal from the circulating signal R1 corresponding to a certain burst signal.

(1-2. Operation)
Next, the operation of the surface acoustic wave measurement apparatus 10 according to the present embodiment will be described using the flowchart of FIG.

  First, a high-frequency signal for generating surface acoustic wave vibrations that circulate around the base material surface of the spherical surface acoustic wave element 90 is generated by the high-frequency signal oscillation unit 11 (step S1). This high-frequency signal is sent to the high-frequency amplification unit 14 via the high-frequency signal coupler 12 and the high-frequency switch unit 13. The high frequency amplifier 14 amplifies the high frequency signal to a high frequency energy level necessary for exciting the spherical surface acoustic wave.

  Subsequently, a high frequency burst signal is applied as an excitation signal to the spherical surface acoustic wave device 90 via the high frequency power switch unit 15 and the changeover switch unit 16 (step S2).

  Supplementally, the output from the high-frequency signal oscillator 11 is always a continuous wave. Therefore, by simultaneously switching the high-frequency switch unit 13 and the high-frequency power switch unit 15 with a control signal from the control unit 18, a high-frequency burst signal in which high-frequency energy is turned on and off is applied to the spherical surface acoustic wave element 90 as an excitation signal. .

  When a high frequency burst signal is applied (ON state), surface acoustic wave vibration is generated on the substrate surface of the spherical surface acoustic wave element 90 by the high frequency energy applied to the interdigital electrode 92, and the surface acoustic wave propagates. The surface 91S goes around multiple times.

  Next, the switch units 13 and 15 are switched to the OFF state by the control signal of the control unit 18, and the matching unit 17 and the preamplifier unit 20 are connected by the operation of the changeover switch unit 16 (step S3). As a result, an electric signal is sent to the preamplifier unit 20 every time a surface acoustic wave passes through the interdigital electrode 92. In addition, since each switch part 13 * 15 is a high isolation characteristic, the high frequency signal which hardly contains the leakage signal component from the high frequency signal oscillation part 11 is output.

  Subsequently, the electrical signal amplified by the preamplifier unit 20 is applied to the circulation signal distributor 21 as a circulation signal. From the circulation signal distributor 21, signals having the same phase and the same level are output. These signals are input to the I system multiplication circuit unit 24 and the Q system multiplication circuit unit 25 as the first circuit signal and the second circuit signal, respectively (step S4). The circular signals input to the I-system multiplication circuit unit 24 and the Q-system multiplication circuit unit 25 are signals having the same level and a phase difference of 0 °.

  On the other hand, a part of the signal output from the high-frequency signal oscillating unit 11 is extracted by the high-frequency signal coupler 12, and the reference signal is input to each of the multiplying circuit units 24 and 25 (step S5).

  Specifically, first, a signal from the high-frequency signal coupler 12 is applied to the reference signal distributor 22. The reference signal distributor 22 outputs two systems of reference signals having the same phase and the same level. One of the two systems of reference signals is directly input to the I system multiplier circuit unit 24 as a first reference signal. The other is input to the phase shifter 23 and the phase is shifted by 90 °. Thereafter, the signal whose phase is shifted by 90 ° is input to the Q-system multiplication circuit unit 25 as the second reference signal. The reference signals input to the I-system multiplication circuit unit 24 and the Q-system multiplication circuit unit 25 have the same level and a phase difference of 90 °.

  In this way, when the rounding signal and the reference signal are input to the multiplication circuit units 24 and 25, a signal representing the product of the rounding signal and the reference signal is output from the multiplication circuit units 24 and 25 (steps). S6).

  Subsequently, the output signals from the multiplication circuit units 24 and 25 pass through the low-pass filter units 26 and 27, and then are amplified by the DC amplification units 28 and 29 to a level where signal processing is easy to be performed. A signal is generated (step S7). These I signal and Q signal include amplitude information and phase information of the surface acoustic wave.

  Next, based on these I signal and Q signal, the state of the surface of the base material of the spherical surface acoustic wave element 90, the change in the amplitude level of the surface acoustic wave vibration due to the adhesion of molecules to the surface of the base material, and the like The change in phase is measured by the measuring unit 30 (step S8).

(1-3. Effect)
As described above, the surface acoustic wave measurement device 10 according to the present embodiment includes the circulation signal distributor 21 that equally distributes the circulation signal into the first circulation signal and the second circulation signal having the same phase, and the excitation signal. A reference signal distributor 22 that equally distributes two first reference signals in phase with each other, and a second reference signal that has a phase orthogonal to the phase of the first reference signal by converting the phase of one first reference signal A phase shifter 23 to be generated, an I-system multiplication circuit unit 24 that outputs an I signal based on the first circulation signal and the first reference signal, and a Q signal that is output based on the second circulation signal and the second reference signal The phase difference between the excitation signal and the circulating signal is accurately determined by the configuration including the Q system multiplication circuit unit 25 that performs the measurement and the measurement unit 30 that measures the amplitude and phase of the surface acoustic wave based on the I signal and the Q signal. Can be measured.

  Further, if the attenuation rate of the circulation signal is measured based on the I signal and the Q signal output from the surface acoustic wave measurement device 10, the change in the amplitude level of the surface acoustic wave can also be measured.

  In addition, according to the surface acoustic wave measurement device 10 according to the present embodiment, it is not necessary to use a local oscillator unlike a general heterodyne system. Therefore, the entire circuit configuration is simplified. Further, not only the amplitude but also the phase difference can be accurately captured.

(Modification)
In this embodiment, the Q signal is obtained by shifting the phase of the reference signal distributed by the reference signal distributor 22 by 90 °, but the Q signal is obtained by shifting the phase of the circulating signal by 90 °. Also good. That is, as shown in FIG. 7, the reference signal distributed by the reference signal distributor 22 is directly input to the Q system multiplication circuit unit 25, and the circulation signal distributed by the circulation signal distributor 21 shifts the phase by 90 °. Enter it later.

  Even with such a configuration, an I signal and a Q signal can be obtained, so that the surface acoustic wave due to the state of the surface of the spherical surface acoustic wave element 90, the adhesion of molecules to the surface of the substrate, etc. It is possible to detect a change in the amplitude and phase of the circular signal generated in the interdigital electrode 92 due to a change in vibration.

<Second Embodiment>
FIG. 8 is a schematic diagram showing a configuration of a surface acoustic wave measurement device 10S according to the second exemplary embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the part same as the already demonstrated part, and the overlapping description is abbreviate | omitted unless there is particular description. In addition, the following description is also omitted in the following embodiments.

  The surface acoustic wave measuring device 10S according to the present embodiment includes a high-frequency signal oscillating unit 11, a high-frequency signal coupler 12, a high-frequency switch unit 13, a high-frequency amplifier unit 14, a high-frequency power switch unit 15, a changeover switch unit 16, a matching unit 17, Control unit 18, preamplifier unit 20, frequency conversion local oscillation unit 40, reference signal coupler 41, frequency converter 42, intermediate frequency filter 43, intermediate frequency amplification unit 44, demodulation type logarithmic amplifier 45, limit amplifier 46 for intermediate frequency A reference frequency converter 47, a reference signal filter 48, a reference signal limit amplifier 49, a phase comparator 50, a low-pass filter unit 51, and a measurement unit 52 are provided.

  That is, the surface acoustic wave measuring device 10S has a so-called heterodyne configuration, and a high-frequency signal oscillated by the high-frequency signal oscillating unit 11 is converted into a local oscillation unit 40 for frequency conversion, which is another oscillation source, and a frequency converter. 42 is converted into a low frequency band (intermediate frequency) that is easy to perform signal processing.

  Next, the operation of the surface acoustic wave measurement device 10S according to the present embodiment will be described with reference to the flowchart of FIG.

  First, in the surface acoustic wave measurement device 10S, the same processes as the processes S1 to S3 described above are executed (T1 to T3). Thereby, a surface acoustic wave is excited on the propagation surface 91S of the spherical surface acoustic wave element 90. An electric signal generated every time the surface acoustic wave passes through the interdigital electrode 92 is sent to the preamplifier unit 20.

  Subsequently, the electric signal amplified by the preamplifier unit 20 is injected into the frequency converter 42 together with the reference signal (frequency f0) generated by the frequency conversion local oscillation unit 40, and a mixing operation is executed (step T4). .

  As a result, signals of various frequency components are generated in the frequency converter 42. The various frequency component signals are narrowed down to only the components in the necessary frequency band (frequency fmr) by the intermediate frequency filter 43 that passes only the signals of the predetermined intermediate frequency components. And the signal narrowed down only to the component of the required frequency band is amplified by the intermediate frequency amplification part 44 (step T5).

  Thereafter, a part of the signal amplified by the intermediate frequency amplifier 44 is input to the demodulating logarithmic amplifier 45. As a result, the amplitude component of the surface acoustic wave vibration that circulates on the surface of the base material of the spherical surface acoustic wave element 90 is obtained as a demodulated output logarithmically compressed by the demodulation type logarithmic amplifier 45 (step T6).

  The demodulated output is monitored by the measurement unit 52, and the change in the situation on the surface of the spherical surface acoustic wave element 90 is measured (step T7).

  On the other hand, after step T5, a part of the signal amplified by the intermediate frequency amplification unit 44 is amplified to the maximum by the intermediate frequency limit amplifier 46. Thereby, a “phase information signal” of the surface acoustic wave is generated and applied to the phase comparator 50 (step T8).

  It is necessary to input a “reference signal” to the phase comparator 50 in order to detect a phase delay of the surface acoustic wave from the phase information signal. This reference signal is obtained as follows. First, a part of the signal output from the high-frequency signal oscillating unit 11 is extracted by the high-frequency signal coupler 12. Further, a part of the signal output from the frequency converting oscillator 40 is taken out by the reference signal coupler 41. These signals are input to the reference signal generating frequency converter 47. The reference signal generation frequency converter 47 generates various frequency component signals, and the reference signal filter 48 selects only a signal having a predetermined intermediate frequency component (frequency fms). Further, the reference signal is generated by amplifying the amplitude of the output signal to the maximum by the reference signal limit amplifier 49.

  When the reference signal and the phase information signal are input to the phase comparator 50, a phase comparison signal is output from the phase comparator 50 (step T9). The phase comparison signal is input to the measurement unit 52 via the low-pass filter unit 51. In the measurement unit 52, the change in the phase difference of each signal is changed to a direct current change. Then, by monitoring this, the phase difference is measured (step T10).

  As described above, the surface acoustic wave measurement device 10S according to the present embodiment includes the frequency conversion local oscillation unit 40 and the frequency converter 42. Therefore, the surface acoustic wave measurement device 10S has high accuracy by converting the circulation signal to an intermediate frequency. The change in phase difference can be measured.

<Others>
Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine a component suitably in different embodiment.

It is a schematic diagram which shows the structure of the surface acoustic wave measuring device 10 which concerns on the 1st Embodiment of this invention. It is a schematic diagram which shows the structure of the surface acoustic wave element 90 which concerns on the same embodiment. It is a conceptual diagram for demonstrating operation | movement of the changeover switch part 16 which concerns on the same embodiment. It is a conceptual diagram of the phase difference measuring method by the measuring unit 30 according to the embodiment. It is a conceptual diagram of the measuring method of the amplitude change by the measurement part 30 concerning the embodiment. It is a flowchart for demonstrating operation | movement of the surface acoustic wave measuring device 10 which concerns on the same embodiment. It is a schematic diagram which shows the other structural example of the surface acoustic wave measuring device which concerns on the same embodiment. It is a schematic diagram which shows the structure of the surface acoustic wave measuring device 10S which concerns on the 2nd Embodiment of this invention. It is a flowchart for demonstrating operation | movement of the surface acoustic wave measuring device 10S which concerns on the same embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,10S ... Surface acoustic wave measuring device, 11 ... High frequency signal oscillation part, 12 ... High frequency signal coupler, 13 ... High frequency switch part, 14 ... High frequency amplification part, 15 ... High-frequency power switch unit, 16 ... changeover switch unit, 17 ... matching unit, 18 ... control unit, 20 ... preamplifier unit, 21 ... circulating signal distributor, 22 ... reference signal distributor 23... Phase shifter 24... I system multiplier circuit section 25... Q system multiplier circuit section 26 and 27... Low pass filter section 28 and 29. ... Measurement unit, 40 ... Local oscillator for frequency conversion, 41 ... Coupler for reference signal, 42 ... Frequency converter, 43 ... Intermediate frequency filter, 44 ... Intermediate frequency amplification unit 45 ... demodulation type logarithmic amplifier, 46 ... Inter frequency limit amplifier, 47... Reference frequency converter, 48... Reference signal filter, 49... Reference signal limit amplifier, 50... Phase comparator, 51. 52 ... Measurement unit, 90 ... Spherical surface acoustic wave, 91 ... Substrate, 91S ... Propagation surface, 92 ... Interdigital electrode.

Claims (4)

In a surface acoustic wave measurement device that applies an excitation signal to an electrode of a spherical surface acoustic wave element and measures a vibration change of the surface acoustic wave from a circular signal of the surface acoustic wave excited by the excitation signal.
Detection means for detecting a surface acoustic wave based on the excitation signal and the circular signal;
Measuring means for measuring a vibration change of the surface acoustic wave detected by the detecting means;
With
The detection means includes
Means for generating a first reference signal having a frequency different from that of the excitation signal;
First signal generating means for generating a signal of a plurality of frequency components based on the circular signal and the first reference signal;
First extraction means for extracting a signal of a predetermined intermediate frequency component from the generated signal;
First amplification means for amplifying the extracted signal;
With
The measuring means includes
Means for generating a phase information signal based on the amplified signal;
Second signal generating means for generating signals of a plurality of frequency components based on the excitation signal and the first reference signal;
Second extraction means for extracting a signal of a predetermined intermediate frequency component from signals generated by the second signal generation means;
Second amplification means for amplifying the signal extracted by the second extraction means to generate a second reference signal;
Means for generating a plurality of phase comparison signals based on the generated phase information signal and the second reference signal;
A surface acoustic wave measuring apparatus comprising: means for measuring a phase difference between the generated phase comparison signals . The surface acoustic wave measurement device according to claim 1,
The measuring means includes
Means for demodulating the amplitude component of the surface acoustic wave based on the signal amplified by the first amplification means;
A surface acoustic wave measuring device comprising: means for measuring the demodulated amplitude component . In a surface acoustic wave measurement method of applying an excitation signal to an electrode of a spherical surface acoustic wave element and measuring a vibration change of the surface acoustic wave from a circular signal of the surface acoustic wave excited by the excitation signal,
  A detection step for detecting a surface acoustic wave based on the excitation signal and the circular signal;
  A measurement step for measuring a vibration change of the surface acoustic wave detected by the detection step;
  With
  The detection step includes
  Generating a first reference signal having a frequency different from that of the excitation signal;
  A first signal generating step for generating a signal of a plurality of frequency components based on the circular signal and the first reference signal;
  A first extraction step of extracting a signal of a predetermined intermediate frequency component from the generated signal;
  A first amplification step for amplifying the extracted signal;
  With
  The measurement step includes
  Generating a phase information signal based on the amplified signal;
  A second signal generation step of generating a signal of a plurality of frequency components based on the excitation signal and the first reference signal;
  A second extraction step of extracting a signal of a predetermined intermediate frequency component from the signals generated in the second signal generation step;
  A second amplification step of amplifying the signal extracted in the second extraction step to generate a second reference signal;
  Generating a plurality of phase comparison signals based on the generated phase information signal and the second reference signal;
  Measuring a phase difference between the generated phase comparison signals;
  A surface acoustic wave measuring method comprising: In the surface acoustic wave measuring method according to claim 3,
  The measurement step includes
  Demodulating the amplitude component of the surface acoustic wave based on the signal amplified in the first amplification step;
  Measuring the demodulated amplitude component;
  A surface acoustic wave measuring method comprising:

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