KR20140119278A - Method for non-contact, non-power and wireless measurement of temperature by surface acoustic wave - Google Patents

Method for non-contact, non-power and wireless measurement of temperature by surface acoustic wave Download PDF

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Publication number
KR20140119278A
KR20140119278A KR1020130033385A KR20130033385A KR20140119278A KR 20140119278 A KR20140119278 A KR 20140119278A KR 1020130033385 A KR1020130033385 A KR 1020130033385A KR 20130033385 A KR20130033385 A KR 20130033385A KR 20140119278 A KR20140119278 A KR 20140119278A
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South Korea
Prior art keywords
surface acoustic
acoustic wave
temperature
temperature sensor
sensor
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KR1020130033385A
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Korean (ko)
Inventor
김기복
정재기
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한국표준과학연구원
한빛이디에스(주)
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Priority to KR1020130033385A priority Critical patent/KR20140119278A/en
Publication of KR20140119278A publication Critical patent/KR20140119278A/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/32—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using change of resonant frequency of a crystal
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/05—Holders; Supports
    • H03H9/10—Mounting in enclosures
    • H03H9/1064—Mounting in enclosures for surface acoustic wave [SAW] devices
    • H03H9/1092—Mounting in enclosures for surface acoustic wave [SAW] devices the enclosure being defined by a cover cap mounted on an element forming part of the surface acoustic wave [SAW] device on the side of the IDT's
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
    • H03H9/25—Constructional features of resonators using surface acoustic waves

Abstract

The present invention relates to a non-powered and contactless surface acoustic wave temperature sensor. According to an embodiment of the present invention, the temperature sensor includes: an antenna which receives a sensor driving signal from a temperature measuring device; an IDT generating surface acoustic waves through the received sensor driving signal; a piezoelectric substrate propagating the surface acoustic waves generated in the IDT; and an acoustic reflector which reflects the surface acoustic waves to propagate again the surface acoustic waves to the IDT.

Description

TECHNICAL FIELD [0001] The present invention relates to a non-contact wireless temperature measurement method using a surface acoustic wave,

The present invention relates to a method for measuring a temperature in a noncontact manner using a surface acoustic wave, and more particularly,

Surface acoustic wave (SAW) was discovered in 1885 by British Rayleigh Sir, and has since become a subject of research by many geophysicists. Surface acoustic waves have been used in electronic devices since the mid-1960s, when an IDT (Inter-Digital Transducer) was fabricated on a piezoelectric body to generate surface acoustic waves. The SAW device changes the propagation characteristics according to the change of the environment around the delay line, which is the path of the surface acoustic wave. By using this characteristic, the SAW device is used as the sensor. The SAW sensor has the advantages of miniaturization, robustness, high reproducibility, low power consumption, and high sensitivity because it operates at high frequencies. In SAW devices, the propagation energy of the surface acoustic wave is concentrated within 1 to 1.5 times the wavelength of the surface of the device. Researches are being conducted to develop a non-contact wireless sensor using the principle of mutual conversion between electromagnetic waves and acoustic waves, which is an advantage of such SAW sensors. Recently, many researches have been made to combine wireless technology with SAW sensor technology due to development of radio communication technology and semiconductor technology using RF. As a result, it is possible to miniaturize the size of the product, reduce the cost, and mass-produce the product. Moreover, it can be applied to structures or facilities that are difficult to access or difficult to measure by using the miniaturized wireless sensing technology. In order to apply the SAW sensor to structural health monitoring (SHM), it is preferable that the sensor signal and the power source are transmitted and received wirelessly. In general, temperature sensors are needed in various fields and researches are being conducted to develop a SAW temperature sensor using temperature characteristics of a piezoelectric substrate. Most studies on the SAW temperature sensor have mainly focused on the structure of the IDT and the influence of the piezoelectric substrate to generate surface acoustic waves.

A study on the influence of the acoustic reflector, which is one of the main components of the surface acoustic wave temperature sensor, and the study on the driving and measuring equipment of the surface acoustic wave temperature sensor, are somewhat lacking. Therefore, it is necessary to understand the structure of the acoustic reflector by comparing and analyzing the signal characteristics of the SAW device according to the structure of the acoustic reflector, which is one of the main elements of the surface acoustic wave temperature sensor.

The present invention proposes a structure of an acoustic reflector suitable for a surface acoustic wave temperature sensor.

In addition, a new noncontact temperature measurement method using a surface acoustic wave temperature sensor is proposed.

In order to solve the above problems, in one embodiment of the present invention, the temperature is measured in a non-contact manner and wirelessly using a frequency change of a surface acoustic wave temperature sensor without a separate power source. Specifically, when a signal for driving a temperature sensor is generated using a temperature measuring device equipped with an antenna and then a signal is transmitted through the antenna, a surface acoustic wave temperature sensor equipped with the antenna receives the signal and drives the temperature sensor And the frequency of the surface acoustic wave generated by the temperature sensor changes according to the temperature change. The temperature measuring device receives the signal again, and the temperature can be measured by analyzing the frequency.

A non-power source non-contact surface acoustic wave temperature sensor that can be provided according to one aspect of the present invention includes: an antenna adapted to receive a sensor driving signal from a temperature measuring device; An IDT generating a surface acoustic wave through the received sensor driving signal; A piezoelectric substrate for propagating the generated surface acoustic wave; An acoustic reflection plate that reflects the propagated surface acoustic wave and propagates back to the IDT; And a delay line for propagating the surface acoustic wave and the reflected reflected wave. At this time, the IDT is in the form of a single electrode, and the acoustic reflector has a comb-like structure.

In this case, the temperature measuring apparatus may include an antenna and a processing unit. The processing unit sequentially transmits a plurality of sensor driving signals having different center frequencies to the surface acoustic wave temperature sensor through the antenna, and detects a plurality of reflection signals for the plurality of sensor driving signals reflected from the surface acoustic wave temperature sensor, A signal is received through the antenna and the temperature may be determined based on the largest maximum reflected signal among the plurality of reflected signals.

According to another aspect of the present invention, there is provided a temperature measuring method for transmitting a plurality of sensor driving signals having different center frequencies to a surface acoustic wave temperature sensor, A transmitting and receiving step of receiving a plurality of reflection signals; And determining a temperature based on the largest reflected signal among the plurality of reflected signals.

At this time, the transmitting and receiving step includes sweeping the frequency of the sensor driving signal from the first frequency to the second frequency, and the determining step may include the step of measuring a value of each of the plurality of reflection signals ; Determining a center frequency of the largest reflected signal among the plurality of reflection signals as a resonance frequency of the surface acoustic wave temperature sensor; And determining a temperature corresponding to the determined resonance frequency.

Here, the surface acoustic wave temperature sensor may include: an antenna; IDT; A piezoelectric substrate; Acoustic reflector; And a delay line, wherein the IDT is in the form of a single electrode, and the acoustic reflector may be a comb-like structure.

According to another aspect of the present invention, there is provided a temperature measuring apparatus comprising: an antenna; And a processing unit. At this time, the processing unit sequentially transmits a plurality of sensor driving signals having different center frequencies to the surface acoustic wave temperature sensor through the antenna, and the plurality of sensor driving signals, which are reflected from the surface acoustic wave temperature sensor, And receives the reflected signal through the antenna. The temperature is determined based on the largest reflected signal among the plurality of reflected signals.

Here, the processing unit is adapted to sweep the frequency of the sensor driving signal from the first frequency to the second frequency, and is adapted to measure a value of each of the plurality of reflection signals, The center frequency of the large maximum reflection signal is determined as the resonance frequency of the surface acoustic wave temperature sensor and the temperature corresponding to the determined resonance frequency is determined to be the measurement temperature.

At this time, the size of each of the plurality of reflection signals may be determined based on a maximum value in the time axis of each of the plurality of reflection signals.

At this time, the maximum value in the time axis can be measured using a peak-and-hold method.

At this time, the magnitude of each of the plurality of reflection signals may be defined as the magnitude of energy of each of the plurality of reflection signals.

At this time, the resonance frequency of the surface acoustic wave temperature sensor may be determined according to the temperature of the surface acoustic wave temperature sensor.

In this case, the processing unit may have a center frequency of 400 MHz to 440 MHz.

Here, the surface acoustic wave temperature sensor may include: an antenna; IDT; A piezoelectric substrate; Acoustic reflector; And a delay line, wherein the IDT is in the form of a single electrode, and the acoustic reflector may have a comb-like structure.

 The present invention can maximize the efficiency of the temperature sensor by forming an acoustic reflector, which is one of the main elements of the temperature sensor, in the form of a comb electrode, and it is possible to measure the temperature accurately by detecting the change in the resonance frequency of the temperature sensor in the wireless detector .

1 is a conceptual diagram of a surface acoustic wave temperature sensor and a temperature measuring device according to an embodiment of the present invention.
2 is a view showing a configuration of a temperature measuring apparatus according to an embodiment of the present invention.
3 is a view showing a surface acoustic wave temperature sensor according to an embodiment.
4 is a view showing an example of various types of acoustic reflector plates that can be used for designing a surface acoustic wave temperature sensor.
5 is a view showing a surface acoustic wave temperature sensor designed according to an embodiment of the present invention.
FIGS. 6A and 6B are graphs actually showing reflection signals reflected from the surface acoustic wave temperature sensor when the surface acoustic wave temperature sensor shown in FIG. 5 is composed of the acoustic reflector shown in FIG.
7 is a view showing a configuration of a temperature measuring apparatus according to another embodiment.
8 is a graph showing changes in the resonance frequency of the surface acoustic wave temperature sensor signal according to the temperature change.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein, but may be implemented in various other forms. The terminology used herein is for the purpose of understanding the embodiments and is not intended to limit the scope of the present invention. In addition, the singular forms used below include plural forms unless the phrases expressly have the opposite meaning.

1 is a conceptual diagram of a surface acoustic wave temperature sensor and a temperature measuring device according to an embodiment of the present invention.

1, the surface acoustic wave temperature sensor 100 may include an IDT 11, a piezoelectric substrate 12, an acoustic reflector 13, a delay line 14, and a first antenna 102. The temperature measuring apparatus 200 may include a processing unit 201 and a second antenna 202.

The processing unit 201 of the temperature measuring apparatus 200 sequentially transmits a plurality of sensor driving signals 31 having different center frequencies to the surface acoustic wave temperature sensor 100 through the second antenna 202.

The surface acoustic wave temperature sensor 100 receives the transmitted sensor driving signals 31 and transmits the received sensor driving signals 31 to the IDT 11. The piezoelectric substrate 12 is vibrated by the sensor drive signal 31 input to the IDT 11 and the surface acoustic wave 15 propagating along the surface of the piezoelectric substrate 12 is generated, To the acoustic reflector (13). The propagated surface acoustic wave 15 is reflected 16 by the acoustic reflector 13 and is transmitted to the temperature measuring device 200 through the first antenna 102 via the delay line 14 and the IDT 11, And the reflection signal 32 are sequentially transmitted.

For example, in the temperature measuring apparatus 200, one sensor drive signal 31 is transmitted to the surface acoustic wave temperature sensor 100, and thereafter one reflection signal 32 is received from the surface acoustic wave temperature sensor 100 have. The temperature measuring apparatus 200 can repeat the process of transmitting another sensor driving signal 31 to the surface acoustic wave temperature sensor 100 thereafter. In another embodiment, the temperature measuring apparatus 200 may synthesize a plurality of sensor driving signals 31 having different center frequencies and transmit them to the surface acoustic wave temperature sensor 100 at one time.

The temperature measuring apparatus 200, which receives the plurality of reflection signals 32 sequentially, measures the temperature based on the plurality of reflection signals 32. Hereinafter, the temperature measuring apparatus 200 will be described in more detail with reference to FIG.

2 is a view illustrating a temperature measuring apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the temperature measuring apparatus 200 may include a processing unit 201, and a second antenna 202. The processing unit 201 includes a microcontroller 21, a digital data storage (DDS) 22, a first filter and an amplifier 23, a switch 24, a second filter and an amplifier 25, A peak-and-hold 26, and a memory 27.

The microcontroller 21 is configured to control the temperature measuring device 200. The microcontroller 21 controls the DDS 22 to sweep a plurality of sensor drive signals 31 having different center frequencies through the DDS 22 from the first frequency to the second frequency. The sensor drive signal 31 is sequentially transmitted to the surface acoustic wave temperature sensor 100 through the second antenna 202 connected to the switch 24 via the first filter and the amplifier 23 and the third switch.

The plurality of reflection signals 32 reflected by the surface acoustic wave temperature sensor 100 and received by the temperature measuring device 200 through the second antenna 202 are transmitted to the second filter and amplifier 25 and the peak- The temperature is determined on the basis of the largest maximum reflected signal among the reflected signals 32, for example, the reflected signal having the largest energy or the reflected peak signal having the largest peak value.

The method of determining the temperature may include measuring a value of each of the plurality of received reflected signals 32 and determining a center frequency of the largest reflected signal among the measured values as resonance of the surface acoustic wave temperature sensor 100 And determines that the temperature corresponding to the resonance frequency is the measurement temperature. That is, the resonance frequency may be changed according to the temperature of the surface acoustic wave temperature sensor 100.

The magnitude of the reflected signal 32 in this embodiment can be determined based on the maximum value in each time axis. The maximum value in the time axis is adapted to be measured using the peak-and-hold 26.

In a modified embodiment, the magnitude of each of the plurality of reflected signals 32 may be defined as the magnitude of the energy of each of the plurality of reflected signals 32.

3, the switch 24 is connected to the first filter and amplifier 23, the second antenna 202, and the second filter and amplifier 25. 3 the switch 24 receives the sensor drive signal 31 from the first filter and amplifier 23 and transmits it to the second antenna 202 and receives the reflected signal 32 through the second antenna 202 And transmits it to the second filter and amplifier 25, and it can be composed of a kind of irreversible element. The center frequency and the temperature value are stored in the memory 27.

In one embodiment of the present invention, the sensor driving signal 31 is capable of adjusting the transmission / reception bandwidth in a center frequency range of, for example, 400 MHz to 440 MHz, and the frequency of the frequency scanning range for transmitting / receiving the surface acoustic wave temperature sensor 100 In one embodiment, the interval per index may be set at 11.72 kHz in the range of 419.3 to 422.3 MHz. Although the first antenna 102 and the second antenna 202 for transmitting and receiving signals between the surface acoustic wave temperature sensor 100 and the temperature measuring apparatus 200 use dipole antennas in the embodiment of the present invention, But may be embodied in different forms and is not limited to the embodiments described herein.

3 is a view showing a surface acoustic wave temperature sensor according to an embodiment.

3, a surface acoustic wave temperature sensor 100 includes a first antenna 102 adapted to receive a sensor driving signal 31 from a temperature measuring device 200, The piezoelectric substrate 12 for propagating the generated surface acoustic wave 15 and the propagated surface acoustic wave 15 are reflected by the IDT 11 for generating the surface acoustic wave 15 and propagated back to the IDT 11 And a delay line 14 for propagating the surface acoustic wave 15 and the reflected wave 16 reflected therefrom. In the preferred embodiment of the present invention, the IDT 11 is a single electrode and the acoustic reflector 13 is a comb-like structure. Various kinds of acoustic reflectors will be described with reference to FIG. 4, which will be described below.

In order to determine the characteristics of the IDT 11 required for designing the surface acoustic wave temperature sensor 100, the electrode shape, the number of electrode pairs, and the characteristics of the piezoelectric substrate 12 must be considered. The IDT 11 has a single IDT structure and a double IDT structure and the interval between the individual comb electrodes of the IDT 11 is calculated by the wavelength of the surface acoustic wave. Since the structure of the single electrode structure is simple and the electrode width is relatively wide, the photolithography process for the electrode implementation is relatively simple, and the spacing of the individual comb electrodes is designed to be one quarter of the wavelength. On the other hand, in the case of the double electrode, since the distance between the comb electrodes is 1/8 times of the wavelength, the electrode width is relatively narrow, which requires a complicated photolithography process. However, since the Bragg reflection of the IDT 11 itself can be minimized, Is often used for a frequency response element which is required. The wavelength? Of the surface acoustic wave is determined by the velocity V s of the piezoelectric substrate 12 and the center frequency f of the surface acoustic wave temperature sensor, as shown in Equation (1).

[Equation 1]

Figure pat00001

In order to determine the characteristics of the piezoelectric substrate 12 required for the design of the surface acoustic wave temperature sensor 100, the electro-mechanical coupling coefficient K 2 and the temperature coefficient of delay, TCD), temperature coefficient of frequency (TCF), and piezoelectric characteristics.

The number of comb electrode pairs is an important factor for determining the intensity and the frequency bandwidth of the surface acoustic wave. When the number of the comb electrode pairs increases, the strain generated for each electrode pair is added due to the principle of superposition, The strength becomes greater.

In order to determine the characteristics of the acoustic reflector 13 necessary for the design of the surface acoustic wave temperature sensor 100, the reflectivity, the reflection bandwidth, and the shape of the reflector should be considered. The reflection force of the reflection plate is determined by the number N of strips of the individual reflection plates. Each reflection plate has a small reflection power r, amplified by the number of strips, and a reflection coefficient R can be expressed by the following equation (2).

&Quot; (2) "

Figure pat00002

If the number of strips is large, the reflection power can be amplified. However, since the reflection bandwidth is reduced as the number of strips increases, a proper number of strips should be designed considering the relationship between the two elements. On the other hand, the reflection bandwidth (B) is determined by the following equation (3).

&Quot; (3) "

Figure pat00003

4 is a view showing various kinds of acoustic reflectors necessary for designing the surface acoustic wave temperature sensor 100 shown in Fig.

As shown in FIG. 4, in order to analyze the shape of the acoustic reflector 13 and the reflectivity according to the number of strips, four types of acoustic reflectors are considered.

A closed type 401 in which the reflection plate is closed, an open type 402 in which the strip end of the reflection plate is opened, an IDT-type 403, and a bar type 47, There are four types of acoustic reflectors. The closed type 401 in which the reflection plate is closed, the open type 402 in which the strip end of the reflection plate is opened, and the open type 402 in which the end of the strip is opened are provided for the IDT- And the number of strips of the strips 13 may be different from each other. That is, the closed type 401 is closed by the close_R3 41 and the close_R5 42, the open type 402 is open_R3 43 and open_R5 44, the IDT-type 403 is by IDT_R7 45 and IDT_R9 46 Can be designed. Analysis of the shape of the acoustic reflector 13 and the reflection power according to the number of strips will be described with reference to FIGS. 6A and 6B.

5 is a view showing a surface acoustic wave temperature sensor designed according to an embodiment of the present invention.

Referring to FIG. 5, in one embodiment of the present invention, the surface acoustic wave temperature sensor 110 may be designed in consideration of the above-described design factors for the IDT, the piezoelectric substrate, and the acoustic reflector. The IDT 51 of the surface acoustic wave temperature sensor 110 can be manufactured in the form of a single electrode having a relatively simple structure and easy photographic processing. The number of electrode pairs of the electrode connection portion 54 can be designed to be 30 pairs in order to obtain surface acoustic waves of appropriate intensity. The center frequency can be designed to 433 MHz, which is the frequency corresponding to the Industrial Scientific Medical (ISM) band, which is a frequency band that can be used in industrial, scientific, and medical fields. The piezoelectric substrate 52 can be designed using a 128 ° rot X LiNbO 3 piezoelectric substrate having a relatively high TCD of 75 ppm / ° C. Considering the above design conditions and the propagation speed (about 4000 m / s) of the piezoelectric substrate 52, the wavelength of the surface acoustic wave is calculated to be 9.21 μm according to Equation 1, and the electrode width of the single electrode structure is 2.3 μm . The acoustic reflector 53 can be designed using an acoustic reflector having a comb-like structure.

The surface acoustic wave temperature sensor 110 designed according to one embodiment of the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

6A and 6B are graphs actually showing reflection signals reflected from the surface acoustic wave temperature sensor in the case where the surface acoustic wave temperature sensor shown in Fig. 5 is composed of various kinds of acoustic reflection plates shown in Fig. 4 . 6A and 6B show results of using a surface acoustic wave temperature sensor having 110? And 220? Delay lines, respectively.

In FIGS. 6A and 6B, the horizontal axis represents the time axis, and the vertical axis represents the magnitude of the reflected signal. 6A, the distance between the IDT 51 and the acoustic reflector 53 is 1.034 mm, and the surface acoustic waves generated and propagated by the IDT 51 are reflected by the acoustic reflector 53, The total traveling distance of returning to the position 51 is 2.068 mm. At this time, since the surface acoustic wave propagation velocity of the piezoelectric substrate 52 is about 4000 m / s, the arrival time 61 of the first reflected and returned signal is calculated to be about 0.52 μs. 6B, the distance from the IDT 51 to the acoustic reflector 53 is 2.068 mm, and the surface acoustic waves generated and propagated in the IDT 51 are reflected by the acoustic reflector 53, The total traveling distance of returning to the receiving port 51 is 4.136 mm, and the signal arrival time 63 is calculated to be about 1.04 μs.

As shown in FIGS. 6A and 6B, in the case of IDT_R9 (62) in FIG. 6A and the case of IDT_R7 (64) in FIG. 6B, it is confirmed that the magnitude of the reflected signal reflected by the acoustic reflector 53 is the largest. Therefore, in the preferred embodiment of the present invention, it can be determined that the acoustic reflector 53 has a comb-like structure.

7 is a view showing a configuration of a temperature measuring apparatus according to another embodiment.

Referring to FIG. 7, the temperature measuring device 210 may include a processing unit 211, and a second antenna 212. The processing unit 211 may include a microcontroller, a DDS, a first filter and an amplifier, a switch 3, a second filter and amplifier, a peak-and-hold, an analog-to-digital converter, and a display.

The microcontroller is configured to control the temperature measuring device 210. The microcontroller controls the DDS and sweeps a plurality of sensor driving signals 31 having different center frequencies from the first frequency to the second frequency through the DDS. The plurality of sensor driving signals 31 are sequentially transmitted to the surface acoustic wave temperature sensor through the second antenna 212 connected to the switch 3 through the first filter and the amplifier. The plurality of reflection signals 32 reflected by the surface acoustic wave temperature sensor and received by the temperature measurement device through the second antenna again undergo peak-and-hold with the second filter and the amplifier, and are transmitted through the analog- And the temperature is determined based on the largest reflected signal of the reflected signal, for example, the reflected signal having the largest energy or the peak value of the reflected signal, so that the determined temperature value is displayed through the display device .

8 is a graph showing changes in the resonance frequency of the surface acoustic wave temperature sensor signal according to the temperature change.

Referring to FIG. 8, a graph 300 shows a resonance frequency according to a temperature change (i.e., a horizontal axis) as a frequency index (i.e., a vertical axis). That is, the value of the vertical axis represents the frequency index of the maximum reflection signal among the plurality of reflection signals 32 received from the surface acoustic wave temperature sensor 100 when a specific temperature is given. As the temperature changes, the resonance frequency index also changes. Therefore, it can be analyzed that accurate temperature measurement is possible using the surface acoustic wave temperature sensor 100 and the temperature measuring device 200.

Since the signal generated by the wireless detector according to the embodiment of the present invention is used as a power source, there is no need for a separate power source for driving the sensor, it is difficult to access or dangerous area, . For example, in the case of a high-voltage transformer, the operator's accessibility is limited and can be utilized in such fields. In addition, the present invention can be utilized variously in fields requiring non-contact temperature measurement, and can be utilized for monitoring temperature distribution in the workplace, environment field, food manufacturing process, and the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the essential characteristics thereof. The contents of each claim in the claims may be combined with other claims without departing from the scope of the claims.

Claims (13)

An antenna adapted to receive a sensor drive signal from a temperature measurement device;
An IDT generating a surface acoustic wave through the received sensor driving signal;
A piezoelectric substrate for propagating the generated surface acoustic wave;
An acoustic reflection plate that reflects the propagated surface acoustic wave and propagates back to the IDT; And
A delay line for propagating the surface acoustic wave and the reflected wave,
/ RTI >
Characterized in that the IDT is of a single electrode type and the acoustic reflector is of a comb-
Non - power contactless surface acoustic wave temperature sensor. The method according to claim 1,
The temperature measuring apparatus includes: an antenna; And a processing unit,
Wherein,
A plurality of sensor driving signals having different center frequencies are sequentially transmitted to the surface acoustic wave temperature sensor through the antenna,
And a plurality of reflection signals for the plurality of sensor driving signals reflected from the surface acoustic wave temperature sensor are received through the antenna,
And the temperature is determined on the basis of the largest maximum reflected signal among the plurality of reflected signals.
Non - power contactless surface acoustic wave temperature sensor. A transmitting and receiving step of transmitting a plurality of sensor driving signals having different center frequencies to a surface acoustic wave temperature sensor and receiving a plurality of reflection signals for the plurality of sensor driving signals reflected from the surface acoustic wave temperature sensor; And
Determining a temperature based on the largest reflected signal among the plurality of reflected signals,
/ RTI >
Method of measuring temperature. The method of claim 3,
The transmitting and receiving step includes sweeping the frequency of the sensor driving signal from a first frequency to a second frequency,
Wherein the determining comprises:
Measuring a value of each of the plurality of reflection signals;
Determining a center frequency of the largest reflected signal among the plurality of reflection signals as a resonance frequency of the surface acoustic wave temperature sensor; And
And determining a temperature corresponding to the determined resonant frequency.
Method of measuring temperature. The method of claim 3,
The surface acoustic wave temperature sensor comprises: an antenna; IDT; A piezoelectric substrate; Acoustic reflector; And a delay line,
Characterized in that the IDT is of a single electrode type and the acoustic reflector is of a comb-
Method of measuring temperature. antenna; And a processing unit,
Wherein,
A plurality of sensor driving signals having different center frequencies are sequentially transmitted to the surface acoustic wave temperature sensor through the antenna,
And a plurality of reflection signals for the plurality of sensor driving signals reflected from the surface acoustic wave temperature sensor are received through the antenna,
And a controller configured to determine a temperature based on the largest one of the plurality of reflection signals,
Temperature measuring device. The method according to claim 6,
Wherein,
Sweep the frequency of the sensor driving signal from a first frequency to a second frequency,
And to measure a value of each of the plurality of reflection signals,
The center frequency of the largest reflected signal among the plurality of reflection signals is determined as the resonance frequency of the surface acoustic wave temperature sensor,
And to determine that the temperature corresponding to the determined resonance frequency is the measurement temperature.
Temperature measuring device. 8. The method of claim 7,
The size of each of the plurality of reflection signals may be,
A plurality of reflection signals, each of which is determined based on a maximum value in a time axis of each of the plurality of reflection signals,
Temperature measuring device. 9. The method of claim 8,
The maximum value in the time axis is measured using a peak-and-hold method.
Temperature measuring device. 8. The method of claim 7,
Wherein a magnitude of each of the plurality of reflection signals is a magnitude of an energy of each of the plurality of reflection signals,
Temperature measuring device. The method according to claim 6,
Wherein a resonance frequency of the surface acoustic wave temperature sensor is determined according to a temperature of the surface acoustic wave temperature sensor.
Temperature measuring device. 8. The method of claim 7,
Wherein the processing unit is configured such that the plurality of sensor drive signals have a center frequency of 400 MHz to 440 MHz,
Temperature measuring device. The method according to claim 6,
The surface acoustic wave temperature sensor comprises: an antenna; IDT; A piezoelectric substrate; Acoustic reflector; And a delay line,
Characterized in that the IDT is of a single electrode type and the acoustic reflector is of a comb-
Temperature measuring device.
KR1020130033385A 2013-03-28 2013-03-28 Method for non-contact, non-power and wireless measurement of temperature by surface acoustic wave KR20140119278A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101654367B1 (en) * 2016-02-17 2016-09-05 지투파워 (주) Wireless temperature detection system of high voltage distributing board, low voltage distributing board, distributing board, motor control board by detecting surface acoustic wave
WO2017200117A1 (en) * 2016-05-17 2017-11-23 한빛이디에스(주) Wireless temperature measuring apparatus using saw device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101654367B1 (en) * 2016-02-17 2016-09-05 지투파워 (주) Wireless temperature detection system of high voltage distributing board, low voltage distributing board, distributing board, motor control board by detecting surface acoustic wave
WO2017200117A1 (en) * 2016-05-17 2017-11-23 한빛이디에스(주) Wireless temperature measuring apparatus using saw device

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