JPH04207618A - Surface acoustic wave resonator - Google Patents
Surface acoustic wave resonatorInfo
- Publication number
- JPH04207618A JPH04207618A JP33814190A JP33814190A JPH04207618A JP H04207618 A JPH04207618 A JP H04207618A JP 33814190 A JP33814190 A JP 33814190A JP 33814190 A JP33814190 A JP 33814190A JP H04207618 A JPH04207618 A JP H04207618A
- Authority
- JP
- Japan
- Prior art keywords
- comb
- acoustic wave
- surface acoustic
- wave resonator
- line electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 27
- 239000000758 substrate Substances 0.000 claims abstract description 9
- 230000005284 excitation Effects 0.000 claims 1
- 238000006073 displacement reaction Methods 0.000 abstract description 3
- 230000005855 radiation Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明はＶＨＦ帯及びＵＨＦ帯の発振子や、バンドパス
フィルターとして機能する弾性表面波共振子に関し、特
に１ポート型の弾性表面波共振子に関するものであるっ
従来の技術
近年、弾性表面波共振子は小型でかっＶＨＦ帯からＵＨ
Ｆ帯にわたり所望の周波数で直接発振が可能な発掘子と
して、各種の発振回路に広く利用されるようになってき
た。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a VHF band and UHF band oscillator and a surface acoustic wave resonator that functions as a bandpass filter, and particularly relates to a one-port surface acoustic wave resonator. Conventional technology In recent years, surface acoustic wave resonators have grown in size from the VHF band to the UH band.
It has come to be widely used in various oscillation circuits as a probe capable of directly oscillating at a desired frequency over the F band.
従来、この種の弾性表面波共振子は第６図に示すような
構成であった。第６図において、１は圧電基板、２はグ
レーティング反射器、３は櫛形電極であり、通常櫛形電
極３は連続して配置され、その両側にグレーティング反
射器２を配置するのが一般的であった。Conventionally, this type of surface acoustic wave resonator has had a configuration as shown in FIG. In FIG. 6, 1 is a piezoelectric substrate, 2 is a grating reflector, and 3 is a comb-shaped electrode. Usually, the comb-shaped electrodes 3 are arranged continuously, and the grating reflectors 2 are arranged on both sides. Ta.
第７図は従来の弾性表面波共振子の共振特性の一例を示
している。FIG. 7 shows an example of the resonance characteristics of a conventional surface acoustic wave resonator.
発明が解決しようとする課題
しかしながら、このような従来の構成では、共振周波数
の低域側にスプリアスを生じ、例えば電圧制御発振器を
構成した際に可変周波数幅を大きくとれないという問題
があった。これは、高次縦モードによる応答によるもの
であり、前述のような櫛形電極を連続して配置した１ポ
一ト型弾性表面波共振子では、奇数次の高次縦モードに
よる電荷を相殺することができないためである。Problems to be Solved by the Invention However, such conventional configurations have the problem of generating spurious waves on the low-frequency side of the resonant frequency, making it impossible to increase the variable frequency width when, for example, configuring a voltage controlled oscillator. This is due to the response due to higher-order longitudinal modes, and in a one-point surface acoustic wave resonator in which comb-shaped electrodes are arranged in series as described above, the charge due to odd-order higher-order longitudinal modes is canceled out. This is because they are unable to do so.
本発明はこのような問題を解決するもので、共振周波数
の低域側にスプリアス応答のない弾性表面波共振子を提
供することを目的とするものである○
課題を解決するだめの手段
このような課題を解決するだめに本発明の弾性表面波共
振子は、圧電性を有する基板上に、１組の櫛形電極と、
その両側にグレーティング反射器を形成し、かつ前記櫛
形電極の一部を間引いて不連続にしたものである。The present invention is intended to solve these problems, and aims to provide a surface acoustic wave resonator that does not have spurious responses on the low-frequency side of the resonant frequency. In order to solve these problems, the surface acoustic wave resonator of the present invention includes a set of comb-shaped electrodes on a piezoelectric substrate, and
Grating reflectors are formed on both sides of the electrode, and a portion of the comb-shaped electrode is thinned out to make it discontinuous.
作用
この構成により、弾性表面波共振子の櫛形電極全体で、
高次縦モードに起因する電荷を相殺することとなり、共
振周波数の低域側に表れるスプリアスを抑圧することが
できる。Effect With this configuration, the entire comb-shaped electrode of the surface acoustic wave resonator
Charges caused by higher-order longitudinal modes are canceled out, and spurious noise appearing on the low-frequency side of the resonance frequency can be suppressed.
実施例
第１図は本発明の一実施例による弾性表面波共振子の平
面図であり、第１図において、１１は圧電性を有する基
板であり、その表面に１組の櫛形電極１２と、その櫛形
電極１２の両側に位置するグレーティング反射器１３が
それぞれ構成されている。そして、櫛形電極１２はその
全長をＬとしたとき、両端からＬ／６のところからＬ／
６の長さだけそれぞれ間引いた構成になっている。Embodiment FIG. 1 is a plan view of a surface acoustic wave resonator according to an embodiment of the present invention. In FIG. 1, 11 is a piezoelectric substrate, on the surface of which a set of comb-shaped electrodes 12 are provided. Grating reflectors 13 located on both sides of the comb-shaped electrode 12 are respectively configured. When the entire length of the comb-shaped electrode 12 is L, the comb-shaped electrode 12 starts from L/6 from both ends.
The structure is such that each length is thinned out by 6 lengths.
第２図は本発明の共振子における高次縦モードの変位分
布を示したもので、櫛形電極１２を前述の構成にするこ
とにより、３次モードの電荷が相殺されることがわかる
。FIG. 2 shows the displacement distribution of the higher-order longitudinal mode in the resonator of the present invention, and it can be seen that by configuring the comb-shaped electrode 12 as described above, the charge of the third-order mode is canceled out.
第３図は本発明の第２の実施例による弾性表面波共振子
の平面図であり、第３図において、３１は圧電性を有す
る基板であり、その表面に１組の櫛形電極３２と、その
両側に位置するグレーティング反射器３３がそれぞれ構
成されており、前記櫛形電極３２の間引かれたところに
ダε−電極３４を配置したものである。このダε−電極
３４は、主共振の共振特性の劣化を抑えるのに有効であ
る。FIG. 3 is a plan view of a surface acoustic wave resonator according to a second embodiment of the present invention. In FIG. 3, 31 is a piezoelectric substrate, and a set of comb-shaped electrodes 32 are provided on the surface of the substrate. Grating reflectors 33 are located on both sides of the grating reflectors 33, and da-ε-electrodes 34 are arranged at thinned-out areas of the comb-shaped electrodes 32. This ε-electrode 34 is effective in suppressing deterioration of the resonance characteristics of the main resonance.
第４図は本発明の第２の実施例による弾性表面波共振子
の共振特性を示している。FIG. 4 shows the resonance characteristics of a surface acoustic wave resonator according to a second embodiment of the present invention.
本発明の第２の実施例では、従来の構成による弾性表面
波共振子に比べて、共振周波数の低域側のスプリアスが
抑圧されている。In the second embodiment of the present invention, spurious on the low-frequency side of the resonant frequency is suppressed compared to a surface acoustic wave resonator having a conventional configuration.
第５図は、本発明のさらに他の実施例を示すもので、櫛
形電極５２の間引かれたところにグレーティング反射器
５４を配置したものである。この構成でも同じようにス
プリアスが抑圧される。第５図において、５１は圧電性
を有する基板、５３は櫛形電極５２の両側に設けられた
グレーティング反射器である。FIG. 5 shows still another embodiment of the present invention, in which a grating reflector 54 is arranged in a thinned-out area of the comb-shaped electrode 52. Spurious signals are suppressed in the same way with this configuration. In FIG. 5, 51 is a piezoelectric substrate, and 53 is a grating reflector provided on both sides of the comb-shaped electrode 52.
なお、前記実施例においては、櫛形電極の間引き方を両
端からＬ／６の長さとしたが、この間引き方に限定され
るものではなく、高次縦モードの電荷が効率よく櫛形電
極全体で相殺される間引き方であればよい。In the above embodiment, the comb-shaped electrode was thinned out to a length of L/6 from both ends, but the thinning method is not limited to this, and the charge in the higher-order longitudinal mode can be efficiently canceled out over the entire comb-shaped electrode. Any thinning method that can be used is sufficient.
発明の効果
以上のように本発明によれば、圧電性を有する基板上に
１組の櫛形電極と、その両側にグレーティング反射器を
形成し、かつ前記櫛形電極の一部を間引いて不連続にし
、例えば櫛形電極の全長をＬとしたとき、櫛形電極の両
側から各々Ｌ／６ずつ残してＬ／６だけ間引き、中央部
を残した構成にすることによシ、弾性表面波共振子の共
振周波数の低域側のスプリアスを抑圧することができる
。Effects of the Invention As described above, according to the present invention, a set of comb-shaped electrodes and grating reflectors are formed on both sides of the comb-shaped electrode on a piezoelectric substrate, and a part of the comb-shaped electrode is thinned out to make it discontinuous. For example, when the total length of the comb-shaped electrode is L, the resonance of the surface acoustic wave resonator can be improved by thinning out the comb-shaped electrode by L/6, leaving L/6 on each side of the comb-shaped electrode, and leaving the central part. It is possible to suppress spurious on the low frequency side.
さらに、間引いたところにダε−電極または別のグレー
ティング反射器を配置することにより、主共振の共振特
性の劣化を抑えることが可能であるため、優れた特性を
有する弾性表面波共振子を提供することができるという
効果が得られる。Furthermore, by placing ε-electrodes or another grating reflector in thinned out areas, it is possible to suppress the deterioration of the resonance characteristics of the main resonance, providing a surface acoustic wave resonator with excellent characteristics. The effect of being able to do this is obtained.
第１図は本発明の一実施例による弾性表面波共振子を示
す平面図、第２図は同共振子の高次縦モードによる変位
分布を示す図、第３図は本発明の第２の実施例による弾
性表面波共振子を示す平面図、第４図は同共振子の共振
特性を示す図、第６図は本発明のさらに他の実施例によ
る弾性表面波共振子を示す平面図、第６図は従来の弾性
表面波共振子を示す平面図、第７図は同共振子の共振特
性を示す図である−
１１．３１．５１・・・・・・圧電性を有する基板、１
２．３２．５２・・・・・櫛形電極、１３，３３゜５３
・・・・グレーティング反射器、３４・・・・−ダミー
電極、５４ ・・・・別のグレーティング反射器。
代理人の氏名 弁理士 小鍜治 明 ほか２名第１図
／／−Ｘお
１２−−一響刑＠麺
第２図
第３図
第４図
ｒ
周 波 敷
第５図FIG. 1 is a plan view showing a surface acoustic wave resonator according to an embodiment of the present invention, FIG. 2 is a diagram showing a displacement distribution due to higher-order longitudinal modes of the resonator, and FIG. 3 is a plan view showing a surface acoustic wave resonator according to an embodiment of the present invention. FIG. 4 is a plan view showing a surface acoustic wave resonator according to an embodiment; FIG. 4 is a diagram showing resonance characteristics of the resonator; FIG. 6 is a plan view showing a surface acoustic wave resonator according to still another embodiment of the present invention; FIG. 6 is a plan view showing a conventional surface acoustic wave resonator, and FIG. 7 is a diagram showing the resonance characteristics of the resonator.
2.32.52...Comb-shaped electrode, 13,33°53
... Grating reflector, 34... - dummy electrode, 54 ... Another grating reflector. Name of agent: Patent attorney Akira Okaji and two others Figure 1 //-
Claims (4)
の両側にグレーティング反射器を形成し、かつ前記櫛形
電極の一部を間引いて不連続にしたことを特徴とする弾
性表面波共振子。(1) A surface acoustic wave characterized by forming a set of comb-shaped electrodes and grating reflectors on both sides on a piezoelectric substrate, and thinning out a part of the comb-shaped electrodes to make them discontinuous. resonator.
の両側から各々Ｌ／６ずつ残してＬ／６だけ間引き、か
つ中央部を残したことを特徴とする特許請求の範囲第１
項記載の弾性表面波共振子。(2) When the total length of a set of comb-shaped electrodes is L, the comb-shaped electrodes are thinned out by L/6, leaving L/6 from each side, and leaving the central part. 1
The surface acoustic wave resonator described in .
とは関係ないダミー電極を配置したことを特徴とする特
許請求の範囲第１項記載の弾性表面波共振子。(3) A surface acoustic wave resonator according to claim 1, characterized in that dummy electrodes unrelated to surface acoustic wave excitation are arranged in places where the comb-shaped electrodes are thinned out.
グ反射器を配置したことを特徴とする特許請求の範囲第
１項記載の弾性表面波共振子。(4) The surface acoustic wave resonator according to claim 1, characterized in that another grating reflector is disposed in a place where the comb-shaped electrodes are thinned out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33814190A JPH04207618A (en) | 1990-11-30 | 1990-11-30 | Surface acoustic wave resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33814190A JPH04207618A (en) | 1990-11-30 | 1990-11-30 | Surface acoustic wave resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04207618A true JPH04207618A (en) | 1992-07-29 |
Family
ID=18315304
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33814190A Pending JPH04207618A (en) | 1990-11-30 | 1990-11-30 | Surface acoustic wave resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04207618A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5561408A (en) * | 1993-05-19 | 1996-10-01 | Nec Corporation | Saw resonator bandpass filter with asymetric apodized transducers to suppress a spurious response |
| JP2002353777A (en) * | 2001-05-29 | 2002-12-06 | Toyo Commun Equip Co Ltd | Surface acoustic wave filter |
| US6552632B2 (en) * | 2001-04-20 | 2003-04-22 | Fujitsu Limited | Surface acoustic wave resonator with withdrawn electrodes and surface acoustic wave ladder filter using same |
| JP2020098970A (en) * | 2018-12-17 | 2020-06-25 | 京セラ株式会社 | Elastic surface wave element, splitter, and communication device |
-
1990
- 1990-11-30 JP JP33814190A patent/JPH04207618A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5561408A (en) * | 1993-05-19 | 1996-10-01 | Nec Corporation | Saw resonator bandpass filter with asymetric apodized transducers to suppress a spurious response |
| US6552632B2 (en) * | 2001-04-20 | 2003-04-22 | Fujitsu Limited | Surface acoustic wave resonator with withdrawn electrodes and surface acoustic wave ladder filter using same |
| JP2002353777A (en) * | 2001-05-29 | 2002-12-06 | Toyo Commun Equip Co Ltd | Surface acoustic wave filter |
| JP2020098970A (en) * | 2018-12-17 | 2020-06-25 | 京セラ株式会社 | Elastic surface wave element, splitter, and communication device |
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