WO1999037022A1 - Filtre et transducteur a ondes acoustiques de surface avec inversion de la reflexion - Google Patents
Filtre et transducteur a ondes acoustiques de surface avec inversion de la reflexion Download PDFInfo
- Publication number
- WO1999037022A1 WO1999037022A1 PCT/JP1999/000126 JP9900126W WO9937022A1 WO 1999037022 A1 WO1999037022 A1 WO 1999037022A1 JP 9900126 W JP9900126 W JP 9900126W WO 9937022 A1 WO9937022 A1 WO 9937022A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- electrode
- electrode finger
- reflection
- idt
- acoustic wave
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/64—Filters using surface acoustic waves
- H03H9/6423—Means for obtaining a particular transfer characteristic
- H03H9/6433—Coupled resonator filters
- H03H9/6436—Coupled resonator filters having one acoustic track only
-
- 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
- H03H9/125—Driving means, e.g. electrodes, coils
- H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves
-
- 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
- H03H9/125—Driving means, e.g. electrodes, coils
- H03H9/145—Driving means, e.g. electrodes, coils for networks using surface acoustic waves
- H03H9/14517—Means for weighting
- H03H9/14526—Finger withdrawal
Definitions
- the present invention relates to a surface acoustic wave converter (hereinafter, referred to as an IDT electrode) and a surface acoustic wave device configured using the same, and in particular, by arranging three electrode fingers in one wavelength of an excited surface acoustic wave.
- the present invention relates to a reflection inversion type surface acoustic wave converter in which the amount of attenuation generated on the high frequency side near the pass band and the spurious in the region are improved.
- SAW devices surface acoustic wave devices
- Fig. 5 (a) is a plan view showing an example of the electrode pattern of a conventional first-order to third-order longitudinally coupled dual-mode SAW filter (hereinafter referred to as a dual-mode SAW filter).
- a dual-mode SAW filter Three normal type IDTs 12, 13 and 14 are placed close to each other along the propagation direction of the surface wave on the main surface of 1 and reflectors 15a and 15b are placed on both sides of these IDs. It is arranged.
- Each of the IDTs 12, 13, and 14 is composed of a pair of comb-shaped electrodes having a plurality of electrode fingers interposed therebetween.
- One of the comb-shaped electrodes of the IDT 12 is connected to the input terminal, and the other is connected to the other.
- the strip electrode is grounded.
- one of the IDT 13 and the IDT 14 is connected to the output terminal while being connected to each other, and the other IDT 13 and the IDT 14 are connected to the other and grounded.
- the operation of the dual mode SAW filter shown in Fig. 5 (a) is based on the fact that multiple surface waves excited by the IDTs 12, 13 and 14 are reflected by the reflectors 15a and 1a. As a result of being confined between 5b and generating acoustic coupling between the IDTs 12, 13, and 14, the first and third longitudinal resonance modes are strongly excited, and these two Dual mode using mode Operates as a SAW file. It is well known that the pass band of the dual mode SAW filter is proportional to the frequency difference between the first resonance mode and the third resonance mode.
- Figure 5 (b) shows an example of frequency characteristics when a dual mode SAW filter is simulated.
- the vicinity of the passband The attenuation gradient on the high frequency side does not increase uniformly like the attenuation gradient on the low frequency side, but exhibits a characteristic that the attenuation decreases once at about 13 dB and then increases, that is, a sagging characteristic.
- the small ripple in the vicinity of the passband shown in Fig. 5 (b) is due to the reflectors 15a and 15b. In actual products, it is converted to a bulk wave and becomes smaller, which is practically insignificant. )
- the characteristics are improved by cascading a plurality of double-mode SAW filters with similar characteristics, but the dripping characteristics themselves can be eliminated.
- the problem is that the insertion loss can be doubled or tripled by subordinate connection as is well known.
- the present invention has been made in order to solve the above problems, and provides an IDT electrode structure in which the attenuation in the high frequency side near the pass band and the spurious in the region are improved, and a SAW device using the same.
- the purpose is to: Disclosure of the invention
- the invention according to claim 1 of the reflection inversion type surface acoustic wave converter according to the present invention includes a first electrode finger having a width W1 disposed on a piezoelectric substrate, and a first electrode finger adjacent to the first electrode finger.
- a second electrode finger of width W2 arranged with a gap g1 a third electrode finger of width W3 arranged with a gap g2 adjacent thereto, a first electrode finger and a third
- a surface acoustic wave converter constituted by repeating a plurality of unit sections each consisting of (g 3) / 2 spaces arranged next to the first and second electrode fingers, wherein the first and third electrode fingers are in phase.
- a plurality of the surface acoustic wave converters according to claim 1 are arranged close to each other along the propagation direction of the surface wave, and reflectors are arranged on both sides thereof. It is characterized by being provided and configured.
- a plurality of the surface acoustic wave converters according to the first aspect are arranged close to each other along the propagation direction of the surface acoustic wave, and reflectors are arranged on both sides thereof.
- the ratio of the pitch of the IDT to the pitch of the IDT is greater than 1.
- the phase is a positive phase.
- FIG. 1A is a plan view showing a part of the electrode structure of the present invention
- FIG. 1B is a sectional view showing a surface potential on the electrode.
- FIG. 2 (a) shows six edge surfaces of three IDT electrode fingers arranged at one wavelength of the IDT electrode according to the present invention.
- FIG. 2 (b) shows the reflection vectors E1 to E6 and the composite vector ⁇ 1 of the six edge surfaces.
- FIG. 3 shows the frequency at the lower end of the stop band (solid line), the frequency at the upper end (dash-dot line), the driving force distribution curve (dashed line), the excitation center ( ⁇ ), and the reflection center ( ⁇ ) formed by the IDT electrode according to the present invention.
- FIG. 4 is a graph showing the frequency characteristics of a longitudinally coupled double mode SAW filter configured using the IDT electrode according to the present invention.
- Fig. 5 (a) is a plan view showing the configuration of a conventional first- to third-order longitudinally coupled dual-mode SAW filter, and Fig. 5 (b) shows its frequency characteristics.
- FIG. 6A is a plan view showing a part of a normal type IDT electrode having a continuous periodic structure
- FIG. 6B is a cross-sectional view showing a surface potential on the electrode.
- Fig. 7 (a) shows the four reflective surfaces R1 to R4 at one wavelength of the regular IDT electrode
- Fig. 7 (b) shows the reflective vectors R1 to R4 of the four reflective surfaces and their composite vectors.
- FIG. 8 shows a standing wave (solid line) at the lower end of the stop band formed by the normal type IDT electrode, a standing wave (dashed-dotted line) at the upper end, a power distribution (dashed line), an excitation center ( ⁇ ), and a reflection center.
- FIG. ⁇ Figure 9 (a) shows the filtering characteristics of the first-order to third-order longitudinally coupled dual-mode SAW filter
- Figure 9 (b) shows the reflection coefficient of the IDT electrode and the reflection coefficient of the reflector and the resonance of the first- and third-order modes.
- FIG. 4 is a diagram illustrating a relationship between frequencies f1 and f3. BEST MODE FOR CARRYING OUT THE INVENTION
- Fig. 6 (a) shows an example of the configuration of a normal regular type IDT electrode arranged along the propagation direction of surface acoustic waves on a piezoelectric substrate.A plurality of electrodes are inserted into each other. It is composed of a pair of comb-shaped electrodes having fingers.
- Fig. 6 (b) is a cross-sectional view taken along the line B-B in Fig. 6 (a).
- the surface potential at a certain moment when the IDT electrode is driven by applying a high-frequency voltage between the comb electrodes is shown by a broken line. It is shown.
- Normal type IDT electrodes have electrode fingers of equal width arranged in a half-period cycle, and the reflection coefficient per pair (one basic unit composed of two electrode fingers) based on the center of any IDT electrode finger ⁇ 2 The (reflection vector) will be described with reference to FIGS. 7 (a) and 7 (b).
- the edge surfaces perpendicular to the piezoelectric substrate of each electrode finger are defined as R1 to R4 (here, the symbol R 1 to R 4 each represent an edge surface and also a reflection vector from the edge surface).
- the reflection vectors from the four edge surfaces R1 to R4 are different from the reflection vectors Rl and R3 from the edge surfaces R1 and R3. That is, the magnitude and the phase angle are the same, and the reflection vectors R 2 and R 4 from the edge surfaces R 2 and R 4 are respectively equal. Therefore, As shown in Fig. 7 (b), the reflection vector obtained by combining the four reflection vectors R1 to R4 is the reflection vector per basic unit (pair) ⁇ 2, and the reference vector is based on the center of the electrode finger. When you do, the phase is 7 ⁇ / 2.
- the reflection center is defined as a position where the phase of the reflection coefficient is 1 ⁇ / 2, the reflection center is located at the center of each electrode finger. It is well known that in such a periodic structure having a large number of regular IDT electrode fingers (S AW resonator, S AW resonance filter, etc.), a stop band is formed due to its periodic reflection. What this means is that a surface wave having a frequency within the stop band cannot propagate and a standing wave is formed, and a SAW resonator or SAW Make up the Phil Evening.
- FIG. 8 is a diagram showing the distribution of standing waves at both ends (bottom and top) of the stop band of the normal type IDT electrode.
- the standing wave at the lower end of the stop band shown by the solid line becomes an antinode at the center position of the electrode finger, ie, the reflection center position, and the standing wave at the upper end of the stop band shown by the dashed line becomes a node at the reflection center position.
- the standing wave at the upper end of the stop band indicated by the dashed line is not excited in the infinite periodic structure, but is excited in a finite structure like the actual IDT structure, though it is weaker than the standing wave at the lower end of the stop band. Will be.
- the driving force that excites the surface wave (wavelength) (the force that causes mechanical displacement due to the voltage applied to the interdigital electrode) is, as is well known, the surface potential distribution shown in Fig. 6 (b). It is the lowest order component when Fourier series expansion is performed.
- the calculated driving force is a sine wave of a periodic person, and is indicated by a broken line in FIG. The position of the extremum of the sine wave indicated by the broken line is the excitation center.
- the seal shown in Fig. 8 is the reflection center. And the symbol ⁇ indicates the excitation center.
- the lowest resonance frequency (f 1) at the lower end of the stop band excited strongly and the resonance of the longitudinal higher order mode The filter is constructed using the frequency (fn). It has already been confirmed experimentally and by simulation that these lower-order modes have their lowest order near the lower end of the stop band, and are excited at lower frequencies as the higher-order modes become.
- Figures 9 (a) and 9 (b) show the frequency relationship between the filtering characteristics of a double-mode SAW filter using the resonance frequencies f1 and f3, and the reflection coefficient ⁇ of the IDT and the reflector Ref.
- FIG. Since the reflector pitch is set larger than that of the IDT, the center frequency of the reflection coefficient of the reflector is lower than that of the IDT.
- FIG. 1A is a plan view showing an example of an IDT electrode configuration according to the present invention, in which a first electrode finger 1 having a width W1 and a width W2 having a gap g1 on the right side in the figure.
- a unit consisting of a second electrode finger 2, a third electrode finger 3 of width W3 with a gap g2 to the right in the figure, and a space of (g3) / 2 on both sides of electrode fingers 1 and 3.
- a section, that is, a unit section composed of three electrode fingers per one wave person is repeatedly arranged on the piezoelectric substrate.
- Fig. 1 (b) is a cross-sectional view taken along line A-A of Fig. 1 (a). It shows the surface potential at a certain moment when the IDT electrode is driven by applying a frequency voltage.
- the reflection coefficient ⁇ 1 (reflection vector) per unit section of the IDT electrode with three electrode fingers per wavelength person is obtained.
- any one section of the IDT electrode that is, reflection vectors E1 to E6 (E1 to E6 (E6) from the six edge surfaces E1 to E6 at both ends of each of the electrode fingers 1 to 3 i indicates the edge surface and the reflection vector from the edge at the same time), and six reflection vectors E1 to E6 are obtained as shown in Fig. 2 (b).
- the center of the second electrode finger 2 is used as a reference for reflection for comparison with FIG.
- the composite vector of the reflection vectors E1 to E6 is a reflection vector ⁇ 1, as shown in FIG. 2 (b).
- the reflection vector ⁇ 1 has a phase of 7 ⁇ / 2 at the center of the electrode finger 2, unlike the reflection vector (2 of the regular type IDT electrode shown in FIG. 7 (b). Therefore, their phases differ by 7 °.
- the spatial position of the reflection center due to this phase difference is a position that is spatially separated from the center of the electrode finger 2 by a person / 4 because the phase rotation of the surface wave is contributed by reciprocation. That is, in the IDT electrode according to the present invention, the respective standing wave distributions at the upper and lower frequencies of the stop band are as shown in FIG. In FIG. 3, the solid line indicates the standing wave at the frequency at the lower end of the stop band, and the dashed line indicates the standing wave at the frequency at the upper end of the stop band.
- each standing wave distribution is also shifted by ⁇ / 4.
- the positional relationship between the antinodes and the nodes of the standing wave has been replaced with that of Fig. 8.
- the driving force is the lowest order component when the surface potential distribution shown in Fig. 1 (b) is Fourier-series expanded, and the driving force distribution calculated by this is indicated by the broken line in Fig. 3.
- the result is the sine wave curve shown.
- the excitation center ( ⁇ ) is located at the center of the second electrode finger 2
- the reflection center (mouth) is located at a distance of / 4 from the center of the second electrode finger 2.
- the center of the standing wave at the frequency at the upper end of the stop band indicated by the dashed line coincides with the excitation center, the frequency at the upper end of the stop band is strongly excited.
- the node of the standing wave at the frequency at the lower end of the stop band shown by the solid line coincides with the excitation center, indicating that no excitation occurs in the infinite periodic structure.
- the standing wave at the lower end of the stop band shown by the solid line is excited though it is weaker than the standing wave at the upper end of the stop band shown by the dashed line.
- the standing wave at the upper end of the stop band is strongly excited.
- the higher order mode of the frequency at the upper end of the stop band appears at a higher frequency as the order increases, and the longitudinally coupled multiple mode SAW filter using a plurality of lowest order modes and higher order modes is used.
- An evening can be composed.
- the filter characteristic shown in FIG. 4 is based on the vertical coupling double structure in which the IDT electrode 3 (1) according to the present invention is arranged close to the piezoelectric substrate along the propagation direction of the surface wave, and reflectors are arranged on both sides of the IDT electrode 3 (1). Mode This is the frequency characteristic of the SAW fill.
- the normal filter shown in FIG. 5 (b) has one pair of positive and negative electrode fingers, but the IDT electrode of the present invention has three pairs. Electrode fingers (per wavelength person) correspond to a pair of regular fill filters.
- the pitch L R of the reflector pitch is constant during the fill shown in Fig. 5 (b) or the fill shown in Fig. 4, and the ratio of the IDT pitch to the reflector pitch L t / L R was set to 1.015 in the fill of FIG.
- Other parameters are the same as those shown in Fig. 5 (b).
- the role of the upper and lower ends of the stop band indicated by the regular ID ID electrode is
- the roles of the upper end and the lower end of the stop band shown by the IDT electrode according to the present invention are just opposite. In other words, it is possible to realize a filter (or resonator) having frequency characteristics such that the characteristics indicated by the upper and lower frequencies of the stop band of the normal type IDT electrode are interchanged.
- the IDT electrode of the present invention By applying the IDT electrode of the present invention to a longitudinally-coupled multi-mode SAW filter, it is possible to realize a filter that eliminates the sagging of the amount of quenching that previously occurred on the high frequency side near the passband. .
- the IDT electrode of the present invention can be easily applied without using a cascade connection as in the related art. It has become possible to realize the characteristics. Further, by producing a longitudinally coupled multi-mode SAW filter using the IDT electrode of the present invention, it is possible to eliminate the high insertion loss due to the cascade connection as in the related art. Further, by cascading the multi-mode SAW filter using the IDT electrode of the present invention and the multi-mode SAW filter using the conventional normal electrode, the attenuation gradient in both the vicinity of the pass band is sharply increased. A fill-in filter with strong power-off characteristics can be realized.
- the composite mode filter constructed in this way guarantees sufficient attenuation even at frequencies away from the center frequency.
- the description of the sine wave curve and frequency characteristics of the standing wave at the upper and lower ends of the stop band described above is as follows.
- the phase of the reflection coefficient at the center is -7 ⁇ / 2).
- the reflection center even regular type I DT electrodes the electrode finger center From the person / 4 (space center).
- the functions of the upper and lower ends of the stop band of the regular IDT electrode and the newly proposed reflection inversion electrode are exchanged, but the complementary relationship and the utility value of the two do not change.
- the longitudinally coupled multiple mode SAW filter configured using the IDT electrode of the present invention exhibits a good attenuation gradient on the high frequency side near the pass band.
- the cascade connection between the longitudinally coupled multiplex mode SAW filter configured using the normal type IDT and the longitudinally coupled multiplex mode SAW filter configured using the IDT electrode of the present invention provides a near-passband near the passband. This makes it possible to form a filter with a significantly improved damping gradient, which is extremely effective in producing a SAW filter.
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- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP99900333A EP0977356B1 (en) | 1998-01-20 | 1999-01-18 | Reflection inversion surface acoustic wave transducer and filter |
DE69909913T DE69909913T2 (de) | 1998-01-20 | 1999-01-18 | Akustischer oberflächenwandler und filter mit reflektionsumkehrung |
US09/381,424 US6329888B1 (en) | 1998-01-20 | 1999-01-18 | Reflection inversion surface acoustic wave transducer and filter |
NO19994500A NO315345B1 (no) | 1998-01-20 | 1999-09-17 | Transduser for akustiske overflatebolger med refleksjonsomvending, samt longitudinelt koplet multimodus SAW-filter |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP10/23918 | 1998-01-20 | ||
JP02391898A JP3266846B2 (ja) | 1998-01-20 | 1998-01-20 | 反射反転型弾性表面波変換器及びフィルタ |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999037022A1 true WO1999037022A1 (fr) | 1999-07-22 |
Family
ID=12123893
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1999/000126 WO1999037022A1 (fr) | 1998-01-20 | 1999-01-18 | Filtre et transducteur a ondes acoustiques de surface avec inversion de la reflexion |
Country Status (7)
Country | Link |
---|---|
US (1) | US6329888B1 (ja) |
EP (1) | EP0977356B1 (ja) |
JP (1) | JP3266846B2 (ja) |
DE (1) | DE69909913T2 (ja) |
ID (1) | ID22704A (ja) |
NO (1) | NO315345B1 (ja) |
WO (1) | WO1999037022A1 (ja) |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
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JP3391346B2 (ja) * | 2000-04-18 | 2003-03-31 | 株式会社村田製作所 | 縦結合共振子型弾性表面波フィルタ |
JP3414373B2 (ja) * | 2000-07-26 | 2003-06-09 | 株式会社村田製作所 | 弾性表面波装置 |
JP3685102B2 (ja) * | 2001-07-27 | 2005-08-17 | 株式会社村田製作所 | 弾性表面波フィルタ、通信装置 |
JP3764731B2 (ja) * | 2002-10-18 | 2006-04-12 | 富士通メディアデバイス株式会社 | 多重モード弾性表面波フィルタ及び分波器 |
JP2004304513A (ja) | 2003-03-31 | 2004-10-28 | Matsushita Electric Ind Co Ltd | 弾性表面波装置 |
JP4527968B2 (ja) * | 2003-11-26 | 2010-08-18 | 住友ゴム工業株式会社 | 空気入りタイヤ |
CN101040436B (zh) * | 2004-10-22 | 2010-10-20 | 株式会社村田制作所 | 平衡型声表面波滤波器 |
JP2006148622A (ja) * | 2004-11-22 | 2006-06-08 | Seiko Epson Corp | 弾性表面波装置および電子機器 |
US7750533B2 (en) * | 2005-06-21 | 2010-07-06 | Epson Toyocom Corporation | Surface acoustic wave (SAW) device, module and oscillator for improving a Q factor |
JP4294632B2 (ja) * | 2005-10-26 | 2009-07-15 | 富士通メディアデバイス株式会社 | 弾性表面波装置 |
JP4412292B2 (ja) | 2006-02-06 | 2010-02-10 | セイコーエプソン株式会社 | 弾性表面波装置および電子機器 |
JP4868124B2 (ja) * | 2006-02-22 | 2012-02-01 | セイコーエプソン株式会社 | 弾性表面波共振子 |
DE102007063470A1 (de) * | 2007-12-20 | 2009-07-02 | IFW - Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden e.V. | Wandler, Resonator und Filter für akustische Oberflächenwellen |
JP4591800B2 (ja) | 2008-02-20 | 2010-12-01 | エプソントヨコム株式会社 | 弾性表面波デバイスおよび弾性表面波発振器 |
JP4645923B2 (ja) | 2009-02-27 | 2011-03-09 | セイコーエプソン株式会社 | 弾性表面波共振子、および弾性表面波発振器 |
CN102334289B (zh) | 2009-02-27 | 2015-10-07 | 精工爱普生株式会社 | 表面声波谐振器、表面声波振荡器以及电子设备 |
JP5678486B2 (ja) | 2010-06-17 | 2015-03-04 | セイコーエプソン株式会社 | 弾性表面波共振子、弾性表面波発振器および電子機器 |
JP2012049818A (ja) | 2010-08-26 | 2012-03-08 | Seiko Epson Corp | 弾性表面波共振子、弾性表面波発振器、電子機器 |
JP2012049817A (ja) | 2010-08-26 | 2012-03-08 | Seiko Epson Corp | 弾性表面波デバイス、および弾性表面波発振器、ならびに電子機器 |
JP5934464B2 (ja) | 2010-08-26 | 2016-06-15 | セイコーエプソン株式会社 | 弾性表面波共振子、および弾性表面波発振器、ならびに電子機器 |
JP2012060421A (ja) | 2010-09-09 | 2012-03-22 | Seiko Epson Corp | 弾性表面波デバイス、電子機器及びセンサー装置 |
JP2012060418A (ja) | 2010-09-09 | 2012-03-22 | Seiko Epson Corp | 弾性表面波デバイス、電子機器及びセンサー装置 |
JP2012060422A (ja) | 2010-09-09 | 2012-03-22 | Seiko Epson Corp | 弾性表面波デバイス、電子機器及びセンサー装置 |
JP2012060419A (ja) | 2010-09-09 | 2012-03-22 | Seiko Epson Corp | 弾性表面波デバイス、電子機器及びセンサー装置 |
JP2012060420A (ja) | 2010-09-09 | 2012-03-22 | Seiko Epson Corp | 弾性表面波デバイス、電子機器及びセンサー装置 |
JP5652606B2 (ja) | 2010-12-03 | 2015-01-14 | セイコーエプソン株式会社 | 弾性表面波共振子、弾性表面波発振器、及び電子機器 |
JP5648908B2 (ja) | 2010-12-07 | 2015-01-07 | セイコーエプソン株式会社 | 振動デバイス、並びに発振器、および電子機器 |
WO2012137027A1 (en) | 2011-04-07 | 2012-10-11 | Gvr Trade Sa | Surface acoustic wave resonator |
JP6288760B2 (ja) * | 2013-11-20 | 2018-03-07 | 日本電波工業株式会社 | 弾性表面波デバイス、共振子及び発振回路 |
FR3030154B1 (fr) * | 2014-12-10 | 2018-11-23 | Sasu Frec'n'sys | Dispositif de capteur a ondes elastiques de surface a reponse electrique stable |
WO2019094388A1 (en) * | 2017-11-07 | 2019-05-16 | Resonant Inc. | Ultra-wide-band saw sensor with hyperbolically frequency-modulated etched reflector |
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- 1998-01-20 JP JP02391898A patent/JP3266846B2/ja not_active Expired - Fee Related
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1999
- 1999-01-18 EP EP99900333A patent/EP0977356B1/en not_active Expired - Lifetime
- 1999-01-18 DE DE69909913T patent/DE69909913T2/de not_active Expired - Fee Related
- 1999-01-18 ID IDW991062A patent/ID22704A/id unknown
- 1999-01-18 US US09/381,424 patent/US6329888B1/en not_active Expired - Lifetime
- 1999-01-18 WO PCT/JP1999/000126 patent/WO1999037022A1/ja active IP Right Grant
- 1999-09-17 NO NO19994500A patent/NO315345B1/no not_active IP Right Cessation
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US3870975A (en) * | 1974-03-22 | 1975-03-11 | Hazeltine Corp | Surface wave transducer with reduced reflection coefficient |
JPS50126351A (ja) * | 1974-03-22 | 1975-10-04 | ||
US4249146A (en) * | 1979-02-23 | 1981-02-03 | Trw Inc. | Surface acoustic wave resonators utilizing harmonic frequencies |
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Title |
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Also Published As
Publication number | Publication date |
---|---|
DE69909913D1 (de) | 2003-09-04 |
JPH11214958A (ja) | 1999-08-06 |
US6329888B1 (en) | 2001-12-11 |
NO994500D0 (no) | 1999-09-17 |
EP0977356A1 (en) | 2000-02-02 |
JP3266846B2 (ja) | 2002-03-18 |
ID22704A (id) | 1999-12-09 |
EP0977356A4 (en) | 2000-12-06 |
NO994500L (no) | 1999-09-17 |
EP0977356B1 (en) | 2003-07-30 |
NO315345B1 (no) | 2003-08-18 |
DE69909913T2 (de) | 2004-02-26 |
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