TWI323340B - Vibrational wave detection method, and vibrational wave detector - Google Patents

Description

1323340 IX. Description of the Invention: [Technical Field of the Invention] The present invention relates to a vibrating radon detecting method and apparatus for vibrating the intensity of each frequency band of a vibration wave using a resonant frequency material and a plurality of filaments. Sex detection. [Prior Art] There is a resonator array type vibration sensor in which a plurality of resonators having different resonance frequencies are arranged, so that each resonator selectively responds to and resonates with a vibration wave such as a sound wave at a specific resonance frequency, and The resonance level of each resonator is converted into an electrical nickname and output, and the intensity of each frequency band of the vibration wave is detected (for example, Non-Patent Document 2 or Non-Patent Document 2). In the prior vibration sensor, a piezoresistive resistor (Piezoresist) was formed near the support portion of the resonator. The resistance value of the piezoresistive resistor caused by the vibration (resonance) of the resonator by a Wheatstone bridge or the like The change is detected, and the resonance H outputs an electrical output signal. In particular, in the sensor of Non-Patent Document 2, the output of the Wheatstone bridge of each resonator is switched by the multiplexer, and an output signal is obtained. A method of controlling the gain of a specific frequency band of an input vibration wave by a simple circuit configuration of a resonator array type (Patent Document 2 or Patent Document 2) 1 is, for example, a technique of the resonator array type in the technique of Patent Document 1. In the sensor, the respective piezoresistive resistors set in the respective resonant beams are connected in parallel. The benefit of a particular frequency band can be controlled by varying the supply voltage applied to the parallel circuit, or by changing the shape of the voltage resistive resistor to change the resistance value. Further, in the technique of Patent Document 2, the magnitude of the distortion is different from the position of the resonant beam of 120994.doc 1323340. 'The position of the piezoresistive in each resonant beam is adjusted so that the output signal of each frequency band is leveled. The desired level is reached to control the gain of a particular frequency band. Non-Patent Document 1: W. Benecke et al., "a Frequency_Selective, Piezoresistive Silicon Vibration Sensor," Digest of Technical Papers 〇f TRANSDUCERS^855 pp. 105-108 (1985) Non-Patent Document 2: E. peeters et Al," Vibrati (m Signatui<e

Analysis Sensors for Predictive Diagnostics/· Proceedings of SPIEf97, vol. 3224, pp' 220-230 (1997) Patent Document 1. Japanese Patent Laid-Open Publication No. 2000-46639 Patent Document 2: Japanese Patent Laid-Open No. 2-46640 No. [Invention] [The problem to be solved by the invention]

Regarding the processing of vibration phenomena or acoustic signals, the signal is expressed as a complex number, and various amplitudes/phases can be detected, or signals can be demodulated, and various kinds of analysis or conversion, such as the previous sound/vibration sensing of the microphone, are used. A device that converts physical quantities such as sound pressure at various times into electrical signals, and outputs a single instantaneous signal. In general, the conversion of the suffix to the corresponding complex signal must be performed as described below. This operation is non-caused, and it is impossible to calculate the wideband signal. Since Λ 'is practical for the complex performance of the signal = a narrow-band signal as processed in the field of communication. Between the real part and the imaginary part of the analytic function, there is generally the following conversion relationship (Editor of the Mathematical Society, (1) Erbert + to the meeting, the flat series, the rock wave mathematical dictionary 3rd edition 120994.doc 1323340

(1985), 520 pages). On the semi-plane (yg〇) above the complex variable 2 = \+ 丫, the boundary value f(x) on the real axis of the regular function 彡(Z) = U(X, y)+jV(x, y) ) = U (x, 〇), g (x) = _v (x, 〇), f, g is a function of the integral on the real number (f, geL1 (00, when, there is the following [number 1] g (x) = -pv£ifc±〇dt f(x)工·νΤ£ί^ (1) nt relationship. Here pV is the main value of Cauchy [number 2] H is called the Hilbert transform of f (Hilbert transform), f and (4) are Hilbert transform pairs. The Hilbert transform is a function that connects the real and imaginary parts of the analytic function. For physical phenomena, especially vibration phenomena, parsing on a complex plane It is more convenient... Generally speaking, in the vibration phenomenon, the Euler's formula J c〇se+jSlne 'real # and the imaginary part exist—the differential of the other is, as opposed to the displacement or speed, exists "Speed or acceleration". In order to grasp the phenomenon according to the instantaneous value, only know the existence of its relationship 120994.doc 1323340 - the information (such as displacement) is not sufficient, you must know both (such as displacement and speed) Because of reality and imaginary The relationship becomes a Hilbert transform pair, so the above-mentioned g or f can be derived as another, and the integral of the interval expressed as b_) as shown in the formula (1) must be for a certain period (at least in the periodic function) 】Period) observation. The previous vibration wave detection device allows only one information to be detected. If the instantaneous value can be used to detect the information of both the real part and the imaginary part, the phenomenon can be grasped instantaneously. For example, as in the patent literature丨As shown, the frequency characteristic of the voltage-resistance detector corresponding to the resonant frequency of the resonant beam is given, and the dynamically changeable frequency characteristic is realized. However, in the previous method, the load limit of the vibration wave detection is positive and negative. The present invention (4) has been developed in the above-described circumstances, and an object thereof is to provide a vibration wave detecting method and apparatus capable of imparting an arbitrary complex load. A method for detecting a vibration wave according to a first aspect of the present invention is characterized in that the vibration wave is propagated to each other differently (a plurality of resonances of a specific frequency) The resonator detects an electrical output associated with the resonance generated by the respective frequencies of the resonators by a detector provided in each of the resonators, and the phases are different at a frequency common to the detectors of the plurality of resonators An AC bias voltage is applied to each of the resonators; an output of the detector of the plurality of resonators is synthesized. Further, at least one resonator is 120994.doc 1323340 of the plurality of resonators to which the AC bias voltage is applied, In particular, the AC bias voltage divides the plurality of resonators into a plurality of resonators, each of which includes a resonator included in each group of the AC bias voltages having a common amplitude and phase. Preferably, the king extracts the upper sideband of the output synthesized by the plurality of resonators by a filter to detect the signal of the pair by orthogonal correlation detection.

Furthermore, the output of the detection and synthesis of the above complex (four) resonances is transmitted to the above filter by radio. A vibration wave detecting device according to a second aspect of the present invention is characterized by comprising: a plurality of resonators each resonating with a different specific frequency; and a detector for detecting a vibration wave accompanying propagation from said plurality of resonators: And generating an electrical output of each of the resonators at a resonance of the frequency, and providing each of the plurality of resonators; and applying a biasing mechanism to each of the plurality of resonators

The frequency common to the Hilbert detector of the detector is applied to the upper resonators with different phase AC biases; and the output port forming mechanism is synthesized by the detectors disposed in each of the plurality of resonators The output. Further, the AC bias voltage applied by the bias applying means has at least one of the plurality of resonators having different amplitudes. In particular, the bias applying means divides the plurality of resonators into groups, and the subgroups apply a common alternating current amplitude and phase alternating bias voltage to the resonators of the group I20994.do. Preferably, the method includes: a filtering mechanism that synthesizes the synthesized output synthesized by the output synthesizing mechanism, filters the upper sideband and extracts each of the plurality of resonators; and a positive reading mechanism, the pair The above-mentioned chopping mechanism extracts the above-mentioned adjacent wave band into the quadrature correlation detection, and outputs the Hilbert conversion pair signal.

Further, # may include a wireless transmission mechanism that transmits, by radio, a composite output of the output of the detector synthesized by the output synthesizing mechanism to the trajectory mechanism, wherein the detector is provided in each of the plurality of resonators. Preferably, the detector is a piezoresistive. Further, the above detector may be a capacitive element. [Effects of the Invention]

The detector of the above detector is exemplified by the vibration wave detecting method and the vibration wave detecting device of the present invention. Further, an arbitrary composite frequency characteristic can be added and read and transmitted as an RF (Radio Frequency) modulation signal having two degrees of freedom between the real part and the imaginary part. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same or equivalent parts are attached to the same symbols in the drawings, and the description thereof will not be repeated. Hereinafter, an acoustic sensor that uses a vibration wave to be detected as a sound wave will be described as an example. Fig. 1 is a view showing an example of a sensor body of the vibration wave detecting device of the present invention. The sensor body 1 formed on the semiconductor substrate 20 comprises: 120994.doc U23340 a diaphragm 2 that receives an input sound wave; i beams 3 connected by a Xiao film 2; a termination plate 4 connected to a front end of the banner 3; And on both sides of the beam 3, a plurality of (n) resonant beams 51a, 51b 5 5na, 5nb (hereinafter collectively referred to as a resonant beam 5) supported by one side, all of which are formed by semiconductor shattering The resonance beams 5 on both sides have the same resonance frequency, and the resonance beams 5 of the n groups are formed in the opposite direction.

In the present embodiment, in order to make the mathematical processing simple, it is easy to understand that the resonant beams having the same resonance frequency are arranged in pairs on both sides of the beam 3. Even if the resonant beam 5 is disposed only on the side of the beam, the same result can be obtained. However, at this time, the sensitivity of the sensor is 1/2. The width of the beam 3 is the thickest at the end of the diaphragm 2, and gradually tapers from the side of the diaphragm (4) toward the side of the terminating plate 4, and is the thinnest at the end of the terminating plate 4. Further, each of the resonance beams 5 is a resonance H' which is adjusted by the specific (four) resonance. a? Show the resonance frequency f and choose

A plurality of resonant beams 5 such as shai respond to vibrations in a selective manner by the following formula (3). [Number 3]

CaVY (3) where 'C: constant determined by experiment a: thickness of each resonant beam 5 X: length of each resonant beam 5 γ: Young's modulus of material substance (semiconductor s) s: material substance (semiconductor 矽Density 120994.doc • 12· 1323340 From the above formula (3), the resonance frequency £ can be set to an expected value by changing the thickness of the resonant beam 5 by the length X'. Each of the resonant beams 5 has a natural resonant frequency. In this example, 'the thickness a of all the resonance targets 5 is fixed, and the length X is gradually lengthened from the right side (the diaphragm 2 side) to the left side (the end plate 4 side), with the right side (film) On the left side (the side of the end plate 4), the resonance frequency of the vibration of each of the resonant beams 5S] is set from the high frequency to the low frequency. Further, the sensor body 1 having the above configuration is fabricated on a semiconductor substrate 2 using a micromachining technique. The vibration energy input from the diaphragm 2 is distributed to the respective resonant beams 5 through the beam 3, and is absorbed by the mechanical-electrical converter of each resonance system, and converted into signal energy and then extracted. (Embodiment 1) Fig. 2 is a circuit diagram showing an example of a vibration wave detecting device of the present invention which does not use the above-described sensor body 丨. Distortion occurs in each of the resonant beams 5 of the sensor body i. The bismuth (beam 3 side)' is formed with a piezoresistive resistor 6丨&, 61b~6na, 6nb (hereinafter collectively referred to as a piezoresistor 6) containing polycrystalline germanium. The plurality of varistors 6 are connected in parallel, and one end of the varistor 6 is connected to an AC power source 7ia, 711) 71 71, 7111 (hereinafter collectively referred to as an AC power source 7), wherein the AC power source has a common The frequency has a different amplitude and phase, and the other end of the piezoresistive 6 is connected to one of the input terminals of the operational amplifier 1?. The + input terminal of the operational amplifier 10 is grounded. An alternating bias voltage having phases opposite to each other is applied to the opposing resonant beam 5. In Fig. 2, the opposite phase is indicated by the minus sign of the voltage vi. The voltages VI to Vn can be the same. For the phase w~, for example, at least one has a phase different from the others. 120994.doc -13- 1323340 Next, the action of the vibration wave detecting device shown in Fig. 2 will be described. In general, the relative change rate of the resistance value R of the resistor is expressed by the following formula (4), in which the Poisson ratio of the resistor is V, the length is 丨, and the resistivity is p. [Number 4] 6R (Λ 〇 , δ ΐ δρ , , Κ 1 ρ

In the piezoresistive resistor 6 formed on the semiconductor substrate 20, the resistivity changes mainly due to the change in the susceptibility. If the piezoelectric susceptance coefficient is π and the Young's modulus is Ε, the resistance value of the varistor is The relative change rate of R can be expressed by the following formula (5). [Equation 5] The vibration wave detecting device of Fig. 2 refers to the output form as a vibration waveform.

The combined output, that is, the output form is an output form in which the vibration output of each of the resonant beams 5 is a waveform and one signal line is added and output. At this time, the sensor body 1 functions to effectively convert the electrical signal of the mechanical vibration and adjust the frequency characteristics on the electrical signal based on the mechanical frequency decomposition. Fig. 9 is a circuit diagram showing an example of an output form of the sum of the vibration waveforms of the resonant beam $ of the piezoelectric resistor 6 using the sensor body 1. In the circuit of Fig. 9, a positive DC bias is applied to the upper resonant beams 51a to 5na, and a negative DC bias is applied to the lower resonant beams 51lb to 5nb, and the vibration of each resonant beam 5 is transmitted as 120994.doc. 14. 1323340 Adds 1 signal line to the waveform and outputs it. Here, for the sake of easy understanding, the pair of upper and lower resonance beams 5 are vibrated in a reverse phase, and the upper and lower piezoresistors 6 are expanded and contracted in opposite phases. In Fig. 9, for the resistance value of the piezoresistive resistor on the i-th resonant beam 5i, if the upper side is Ri + SRi(t), the lower side is set to Ri_SRi(1), and the voltages of the other common terminals of the upper and lower resistors are set to V0, _V0, the current flowing into the imaginary ground point of the operational amplifier is expressed by the following equation (6). [Number 6]

(6) Further, the feedback resistor Rf is extracted as the vibration voltage expressed by the following equation (7). [Number 7]

(7) Actually, the load Wi of the composite output is variable by adjusting the resistance Ri. However, the fine adjustment or the like when manufacturing the wafer is fixed. It is considered that the output voltage is proportional to the bias voltage ¥〇 in the above method, and the bias voltage is changed for each of the resonant beams 5. Figure i (4) is a circuit diagram showing an example of a composite output of a piezoresistive mode using a plurality of bias voltage lines. Use the circuit in Figure 1 to dynamically adjust the gain by frequency. When the bias voltage of the beam is set to soil Vi, the output voltage v〇ut is expressed by the following formula (8). 120994.doc [Number 8], N v =y oui f 2RfV.) Bu(t)) l ki J , R; >

W However, if the number of the resonant beams 5 increases due to the number of wires passing through the beam 3, it is necessary to perform the bias control for grouping the resonant beams 5 into groups.振动 In the vibration wave detection method shown in Fig. 1〇, the frequency characteristics are variable, but the gains that can be set in each frequency are limited to real numbers. The gain during frequency filtering is real

Or the imaginary number is limited to the case where the impulse response is symmetric or antisymmetric. If it is set in each frequency; if the increase of t is in real numbers, then no arbitrary pulse response can be achieved. ’

In the vibration wave detecting device of the present invention shown in Fig. 2, a variable load filter which realizes a more general frequency response can be realized. As shown in Fig. 2, the resonance frequencies of the i-th resonance beams 5ia and 5ib are set to 丨, the resistance value of the piezoresistive resistor is set to Ri, and the resistance change is set to SRKt). A sinusoidal alternating voltage having a frequency ω, an amplitude of Vi, and a phase of 钐 is applied to individual terminals of the respective varistors 6la. Further, the reverse phase voltage of the same sinusoidal alternating current voltage is supplied to the piezoresistive resistor 6ib on the reverse phase side. The common terminal of the positive phase and the reverse phase voltage is connected to the input terminal of the operational amplifier 10 of the transfer impedance type. The transfer impedance type operational amplifier 10 is a current-voltage conversion amplifier having an input impedance of 〇 and an output impedance of zero. At this time, the current flowing from the i-th resonant beam 5ia and 5ib into the amplifier is expressed by the following formula (9). 1 [9] 120994.doc • 16 · 1323340

Xc〇s(Qt+^) yc〇s(nt+^) κ* + δ^(〇R^aR^t) i -R js -H; cos(Qt + φ. )Fi(t, ω{) (9 Where 'HisVi/Ri is the gain coefficient of the modulation, Fi (t, ω 〇Ξ δ Ιϋ (1) / Ri is the vibration time waveform of the resonant beam 5i. Fi (t, by Fishb〇ne (fish)

The characteristics of the sensor body 1 constructed in the month, the spectral distribution 8 having a narrower frequency band in the vicinity is set as the total number of the resonant beam 5, and the total waveform of the round outflow of the entire resonant beam 5 is as follows ( 1〇) and said. [Number 10] gW^-EH.cosiQt + ^F^^) (1〇) The frequency here and further consider that the output of each resonant beam is assumed to be a sufficiently narrow band.

[Number 11] [Number 12]

HjCosifit + ^)= RejHje^e^} s Re{H(ro.)ejiit| 120994.doc •17- (12) 1323340, ie, F(8) and Η(8) are only positive frequency heart, (4) zero complex function two Then, the wheel current can be expressed by the following formula (13). Here, the imaginary unit is represented by the letter j. X ′ Re represents the real part, and * on the right side of the function symbol indicates a complex conjugate (the same applies hereinafter). [Number 13]

1 N g( 4 2 F* (Η(ωι)βΐηΐ + ^(ω^β-10*)

And —Ίΐτί0 (FU)eJWt+F*U)e_called (HU)e^ + H*U)e-Kh)d&) ~士{eiot J7FU)HU)eiWt& + eJ〇tf F(w) H*(w)eJwtda Jo f% oo + e5〇t| ρ·*(ω)Η(ω)β_Μ(1ω + e-jQt Γ F*U>H*U)eH〇nda) } J〇=~ "ΓΤ一ieeie3.1 f FU)H(oOe^do) } 2a 〇) J 〇

+ Re[^Qt \ F* (ω)Η(ω)ε",α>ιίΙω}} (13)

Jo Equation (12) indicates that the filter result is obtained by the carrier frequency Ω, and the filter result is obtained by the upper band (hereinafter referred to as the upper side band), and the filter result is the inverse of F(co). The resolved input signal f(1)' f(t) = Fl{F(co)} of the Fourier transform (represented by F-1)

The composite frequency characteristic Η(ω) filter result. Also, f * (-t), that is, F 120994.doc 1323340 * (ω) inverse Fourier transform f * (-1) = F - l{F * (ω)} Η (ω); The result is obtained in the lower sideband (hereinafter referred to as the lower sideband). This process is shown in Figure 3. Fig. 3 is a diagram showing the spectral distribution of the effect of amplitude phase modulation after frequency decomposition. The frequency-decomposed input signals are respectively multiplied by a fixed complex amplitude Hi to obtain a frequency offset of only the carrier frequency Ω. These combinations are the multiplication of the frequency characteristics of Η(ω) and the modulation of the carrier of the fixed frequency Ω. For example, the input spectral distribution A decomposed by frequency in a certain resonant beam 5 becomes a spectral distribution β after the frequency shift of only the carrier frequency 卩. The spectral synthesis after decomposition and only the carrier frequency Ω and the frequency offset is obtained as the spectral distribution of the upper sideband. This result differs from the case where only the acoustic signal f(1) is pulsed by the frequency characteristic Η(ω), and then modulated by the carrier frequency Ω. If the frequency characteristic Η(ω) is filtered and modulated by the carrier frequency Ω, it is smashed. The negative frequency of the suffix is the gain change of Η*. In contrast, in the method of the present invention, the gain of Η(ω) which is the same as the positive frequency is multiplied. Figure 4 shows the synthesis, spectral distribution of the frequency offset of the next sideband or Ω. Consider the meaning of each sideband component. Carrier frequency / upload side: band) will be the desired filter, the filter characteristics of the two = ^. Carrier frequency, the component on the left side (τ sideband) is as follows

[Number 14J 120994.doc 1323340 #丄" (.>)·))tdw = eiQt{J:FU)H*u)e ={f (t) *h* (-t) (14) Frequency response Η* (c〇) or the filter output of the impulse response h * (_t). Here, the symbol * between functions represents convolution. Equation (14) is inverse Fourier transform of complex conjugate [15] P CX J〇Η*(ω)θΐω1ά(ϋ = { Η(ω)βΐω<-ι><1ω}* = h* (-t) is derived. It can be seen that the component of the left side of _Ω is in the negative frequency region. The complex conjugate of the output of the desired filter characteristic, the component on the right side of _Ω is the complex number of the filter outputs of the above Η * 0). Further, if the bias voltages V 〇 VVn are equal, the vibration wave detecting device The frequency characteristics are stable. The filter characteristics can be changed by changing the bias voltages V0 to Vn'. As described above, the upper sideband and the lower sideband have different meanings as signals. The synthesized output of the resonant beam 5 must The upper sideband is separated from the lower sideband and demodulated. The synthesized output signal can be directly demodulated and modulated by the carrier frequency Ω, so that it can be directly transmitted by wireless. A block diagram of a configuration example of a wireless vibration wave detecting device. Fig. 5(a) shows a circuit on the sensor side, and Fig. 5(b) shows a circuit on the receiving side. As shown in Fig. 5(a), the sensor is used. On the side, the signal modulated by the sensor body 利用 is impedance-integrated by the transformer 11, and amplified by the amplifier 12 and transmitted wirelessly from the antenna 13S. The receiving side shown in Fig. 5(b) is received by the antenna UR. The signal amplified by amplifying 120994.doc 1323340 ΊΙ 14 is divided into an upper sideband and a lower sideband by a bandpass filter (BPF) 15. At the same time, a PLL (Phase Locked Loop) 16 is used. The carrier frequency Ω is regenerated. The phase shift frequency of 0° and 90° is made by the phase shifter (Phase Shifter) 17 according to the carrier frequency, and the bypass band is separated by the BPF 15 (USB: Upper Side Band). Orthogonal detection. In USB, multiplier 18 is used to multiply the carrier frequency of 90. The carrier frequency of the phase is multiplied, and the detection output is obtained by a low-pass filter (LPF). The two signals after the correlation detection become the set complex load filter The Hilbert conversion pair is obtained. That is, the phase of the 〇° phase obtains the signal of the real part, and the phase of the imaginary part is obtained from the phase of 9. The applied AC bias voltage is not a sine wave. This is because the BPF 15 is properly adjusted to suppress harmonics when the upper sideband is extracted. The AC bias voltage can be, for example, a rectangular wave. As described above, the vibration wave detecting device according to the present invention can realize any complex load. Further, it can be read and transmitted as an RF modulation signal having two degrees of freedom of the real part and the imaginary part in addition to an arbitrary composite frequency characteristic. The vibration wave detecting method of the present invention can be applied to any of the previous cases in which a microphone or a vibration sensor is used. Further, it can also be used in the case where it has not appeared before. According to the characteristics of the complex waveform, the vibration of the time with high decomposition energy is detected. For example, it is possible to detect an abnormal sound that occurs instantaneously in a continuously activated machine. Also, a wideband AM/FM demodulator can be realized. Moreover, the multi-phase output signal can be detected without contradiction, so it is suitable for waveform measurement with high precision 120994.doc 1323340. (Modification of the first embodiment) Fig. 6 shows an example of a vibration wave detecting device in which the resonance beam 5 is divided into groups and an AC bias voltage is applied. When the number of the resonant beams 5 is increased, the number of wires passing through the beam 3 is limited, and it is difficult to apply an AC bias voltage of a different phase to all of the resonant beams 5. For example, as shown in Fig. 6, the resonant beam 5 is divided into groups, and an AC bias voltage having a common amplitude and phase is applied to the resonant beam 5 included in each group for each group.

In the example of Fig. 6, an alternating bias voltage having an amplitude of V1 and a phase is applied to the resonant beams 5U and .... An alternating bias electric dust having an amplitude of _V1 and a phase is applied to the resonant beams 51b and 52b. In the same way, the adjacent two resonant beams 5 are sequentially divided into one group, and the common amplitude and phase AC bias voltages are applied to the respective groups. In this way, the amplitude and phase complex loads of the complex load are _ There is no change, and a plurality of resonant beams 5 may be provided within the limit of the number of wires of the beam 3.

In the example of Fig. 6, the adjacent two resonant beams 5 are in the group of ?, and the amount may be -. Also, the number of the group of resonant beams 5 can be:: the same number. Further, instead of the adjacent resonant beam 5, for example, the group of the vibrating group (4) is not vibrated, the common amplitude is selected for each group (four) common voltages. The A-line is connected to 4 people. ^The parental bias of the phase. The combination of the file and the amplitude of the dust applied to each group can be based on the parent bias.殁13 Frequency characteristics (Embodiment 2) Fig. 7 is a circuit diagram showing an example of a vibration wave 120994.doc -22- 1323340 detecting device of the present invention when the detector is a capacitor. Electrodes 91a, 91b to 9na, 9nb are formed on the semiconductor cymbal substrate 2 at the positions where the front end portions 81a, 81b to 8na, 8nb (hereinafter, referred to as the distal end portion 8) of the respective resonant beam 5 are opposed to each other. (hereinafter, collectively referred to as electrode 9), a capacitor is formed by the front end portion 8 of each resonant beam 5 and each of the electrodes 9 opposed thereto. The front end portion 8 of the resonant beam $ is a movable electrode that can move up and down with vibration, and on the other hand, the electrode 9 formed on the semiconductor substrate 20 is a fixed electrode whose position cannot be moved. Further, if the resonant beam 5 vibrates at a specific frequency, the distance between the opposing electrodes fluctuates, and therefore the capacitance of the capacitor changes. A plurality of electrodes 9 are connected in parallel and connected to one of the input terminals of the operational amplifier 1A. The + input terminal of the operational amplifier 10 is grounded. The front end portion 8 of the resonance 襟 5 is connected to an AC power source 71a, 71b to 7na, 7nb having a common frequency and having different amplitudes and phases. As in the circuit of Fig. 2, an alternating bias voltage having phases opposite to each other is applied to the opposing resonant beam 5. If the particular resonant beam 5 resonates, then the part 8 is caused by its distortion to make the front end of the resonant beam 5

Change, get. When the detector is replaced by a resistor Ri in the capacitor _ ' (4) to 〇 3), the impedance zi of the capacitance Ci of the electric valley is considered.

Zi = l/(jnCi) 'The carrier frequency Ω is fixed and the same as the resistance can be used to output the phase and the piezoresistive 6 At this time, the impedance Zi contains the frequency (angular frequency), so, if only the change is considered , rational. The amplitude Hi contains an imaginary number j, so the situation of 120994.doc -23· 1323340 is changed by 90. The real and imaginary parts of the demodulated output are replaced. It can be read and transmitted as an RF modulation signal with 2 degrees of freedom between the real part and the imaginary part in addition to any composite frequency characteristic.

Is is the same as Is. (Modification of Second Embodiment) Fig. 8 shows an example of a vibration wave detecting device that applies an alternating current f voltage to divide the resonant beam 5 into a group when the detector is a capacitor. If the number of the resonant beams 5 is increased, it is difficult to apply an AC bias voltage having a different phase to all of the resonant beams 5 due to the limitation of the number of wires passing through the beam 3. Similarly to the modification of the first embodiment (Fig. 6), the adjacent two resonance beams 5 are divided into one group, and an AC bias voltage having a common amplitude and phase is applied to each group. In this way, the degree of freedom of the amplitude and phase of the complex load is reduced, but the complex load is not changed, and a plurality of resonant beams 5 can be provided within the limit of the number of wires of the beam 3. In the example of Fig. 8, the adjacent two resonant beams 5 are divided into groups of 丨, and the number of the resonant beams 5 of one group may be three or more. Also, the number of the 丨 group resonance beams 5 may differ for the group. Further, instead of the adjacent resonant beam 5, for example, each of the "vibrating beams 5" may be selected as one set, and a common alternating current amplitude and phase alternating bias voltage may be applied to each group. Which amplitude and phase AC bias voltage is applied to each group' can be designed according to the obtained composite frequency characteristics. As described above, the vibration wave detecting device according to the present invention, even in the detector Any complex negative 胄 can also be realized for the capacitor, and can be read as an RF modulation signal with the real and imaginary parts of the 2 120994.doc •24- 1323340 degrees of freedom in addition to any complex frequency characteristics. In addition, the hardware configuration is an example, and can be arbitrarily changed and corrected. The present application is based on Japanese Patent Application No. 2006-1 33 802, filed on May 12, 2006. The above-mentioned manual, patent application, Capricorn, and the whole figure are incorporated into the [industry availability]

The vibration wave detecting method and apparatus of the present invention can be used for an acoustic sensor of a fault diagnostic apparatus, a hearing aid, a voice recognition system, a communication system, or the like. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an example of a sensor body of a vibration wave detecting device of the present invention. Fig. 2 is a circuit diagram showing an example of a vibration wave detecting device of the present invention. Fig. 3 is a view schematically showing the spectral distribution of the action of amplitude phase modulation after frequency decomposition.

Fig. 4 is an optical distribution diagram of a composite signal in which the frequency difference of the sideband or ?ω is also considered. Fig. 5 (a) and (b) show a block diagram showing a configuration example of the wireless vibration wave detecting device. Figure. The figure is a diagram showing an example of a vibration wave detecting device that does not divide the resonance beam into groups and applies an AC bias voltage. ® 7 series, a circuit diagram showing an example of the vibration wave detecting device of the present invention when the detector is ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ °. Fig. 8 is a view showing an example of a vibration wave detecting device which detects a resonance beam into a group and applies a 120994.doc -25-flow bias voltage when the gas band a ^ blade is a capacitor. Fig. 9 is a circuit diagram showing an example of an output form of a sum of vibration waveforms of a resonant beam of a piezoresistive. The figure is a circuit diagram showing an example of a composite wheel of a piezoresistive method using a plurality of bias voltage lines. [Main component symbol description] 1 2 3 4 10 11 12 > 14 13S, 13R 15 16 17 18 19 20 51a ' 51b ' 52a Sensor body diaphragm beam termination plate operational amplifier transformer amplifier antenna bandpass filter (BPF )

PLL phase shifter (Phase Shifter) multiplier low pass filter (LPF) semiconductor wonderful substrate 52b, resonant beam 5ia, 5ib, 5na, 5nb 61a, 61b, 62a, 62b, piezoresistive 6ia, 6ib, 6na, 6nb 120994 .doc • 26- 1323340

71a, 71b, 72a, 72b, AC power source 7na, 7nb 81a, 81b, 82a, 82b, front end portion 8ia, 8ib, 8na, 8nb 91a, 91b, 92a, 92b, electrode 9ia, 9ib, 9na, 9nb 27-120994. Doc

Claims (1)

U23340 X. Patent application scope ····:= Wave detection method, which is characterized in that it is a plurality of resonators that propagate vibration waves at different specific frequencies, and detects each of the resonances by a detector provided in the resonator The AC bias voltage of the above-mentioned frequency, the electrical output accompanied by the vibration, and the frequency common to the detection 15 of the plurality of resonators for each resonance β phase; The output of the detector of the resonator. 2. The vibration wave detecting method according to claim 1, wherein at least one of the plurality of resonators to which the AC biasing voltage is applied has a different amplitude of the AC bias voltage. 3. The vibration wave detecting method according to claim 1, wherein the plurality of resonators are divided into a plurality of groups, and for each of the groups, a common amplitude and a phase upper AC bias are applied to the resonators included in each group. Voltage. 4. The vibration wave detecting method according to claim 1, wherein the upper sideband of the rounds synthesized by the detector of the plurality of resonators is extracted by a chopper, and the Hilbert transform is outputted by orthogonal correlation detection. The signal to it. 5. The vibration wave detecting method of claim 4, wherein the round of the synthesis of the detectors of the plurality of resonators is transmitted to the ferrite by radio. 6. A vibration wave detecting device, comprising: a plurality of resonators, each of which resonates at a different specific frequency; 120994.doc detectors are disposed on each of the plurality of resonators, and the detection propagates to the above An electrical output accompanying the resonance of each of the resonators at the frequency caused by the vibration waves of the plurality of resonators; and a bias I application mechanism having a frequency common to the detectors provided in each of the plurality of resonators' An AC bias voltage having a different phase is applied to each of the resonators; and an output synthesizing mechanism that synthesizes an output of the detector provided in each of the plurality of resonators. The vibration wave detecting device according to claim 6, wherein the AC bias voltage applied by the bias applying means has a different amplitude on at least one of the plurality of resonators. 8. The vibration wave detecting device of claim 6, wherein the bias applying means divides the plurality of resonators into groups, and applies common amplitude and phase AC bias voltages to the groups of the resonators of the respective groups. . 11. The vibration wave detecting device of claim 6, comprising: a wave-splitting mechanism 'synthesizing output from the output of the detector synthesized by the output synthesizing mechanism, filtering and extracting the upper sideband, the detector being set above And a plurality of resonators; and a quadrature detection mechanism that performs orthogonal correlation detection on the upper sideband extracted by the filtering mechanism, and outputs a signal of the Hilbert conversion pair. 10. The vibration wave detecting device according to claim 9, wherein the wireless transmission mechanism is configured to wirelessly transmit the output to the filter mechanism by outputting 120994.doc 1323340 of the output of the detector synthesized by the output synthesizing mechanism. The device is provided in each of the plurality of resonators. 11. The vibration wave detecting device of claim 6, wherein the detector is a piezoresistive resistor. 12. The vibration wave detecting device of claim 6, wherein the detector is a capacitive element. 120994.doc