JPH03295308A - Surface acoustic wave resonator - Google Patents
Surface acoustic wave resonatorInfo
- Publication number
- JPH03295308A JPH03295308A JP9734590A JP9734590A JPH03295308A JP H03295308 A JPH03295308 A JP H03295308A JP 9734590 A JP9734590 A JP 9734590A JP 9734590 A JP9734590 A JP 9734590A JP H03295308 A JPH03295308 A JP H03295308A
- Authority
- JP
- Japan
- Prior art keywords
- surface acoustic
- resonator
- acoustic wave
- series
- impedance
- 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 20
- 239000000758 substrate Substances 0.000 claims description 6
- 230000037431 insertion Effects 0.000 abstract description 3
- 238000003780 insertion Methods 0.000 abstract description 3
- 230000000694 effects Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
Description
【発明の詳細な説明】
（発明の属する技術分野）
本発明は、圧電基板上に弾性表面波を励振するすだれ状
変換器とその両側にグレーティング反射器を備えたエネ
ルギー閉し込め型弾は表面波共振子に関する。DETAILED DESCRIPTION OF THE INVENTION (Technical Field to which the Invention Pertains) The present invention provides an energy confinement projectile equipped with a transducer in the form of a transducer for exciting surface acoustic waves on a piezoelectric substrate and grating reflectors on both sides of the transducer. Regarding wave resonators.
（従来技術とその問題点）
エネルギー閉じ込め型弾性表面波共振子（以下共振子と
略称する）は、通常、第１図のように圧電基板ｌの表面
に、２つの端子４と５の間（二設置すられ電気信号を弾
性表面波に変換するすたれ状変換器２ （［ｎｔｅｒｄ
ｉｇｉｔａｌ Ｔｒａｎｓｄｕｃｅｒ、 以下ＩＤＴ
と略記する）と、その両側に周期的構造のグレーティン
グ反射器３か配置さた電極構成を有してＩ、ｚる。(Prior art and its problems) An energy-trapped surface acoustic wave resonator (hereinafter abbreviated as a resonator) usually has a structure that is attached between two terminals 4 and 5 on the surface of a piezoelectric substrate l as shown in FIG. 2 installed transducer 2 that converts an electric signal into a surface acoustic wave ([ntterd
Digital Transducer, hereinafter referred to as IDT
It has an electrode configuration in which a grating reflector 3 having a periodic structure is arranged on both sides of the electrode (abbreviated as I, z).
二のような共振子を電圧制画発振器（”ｖｃｏ：Ｖｏｌ
ｔａｇｅ Ｃｏｎｔｒｏｌｅｄ ０ｓｃｉｌａｔｏｒ）
回路の等価インダクタンスとして使用する場合や、フィ
ルりを構成し広帯域化を図る場合は、Ｑが大きくインピ
ーダンスの高い共振子が望ましい。A resonator like 2 is used as a voltage-controlled oscillator (“vco: Vol.
(Controlled 0scillator)
A resonator with a large Q and high impedance is desirable when used as an equivalent inductance in a circuit or when forming a fill to achieve a wide band.
共振子のインピーダンスは、ＩＤＴ２の電極対数と、交
差幅ＷすなわちＩＤＴ電極の互いに交差する部分の長さ
によって決定される。インピーダンスの高い共振子を得
るためには、ＩＤＴ２の対数は容量比γの点からあまり
小さくてきないため、交差幅Ｗを小さくする必要かある
。しかし、グレーティング反射器３は表面波導波路を構
成しており、交差幅Ｗを小さくすると表面波の回折によ
り表面波エネルギーが導波路領域から外部へ漏洩する分
か増加するため、共振子のＱが低下する欠点かあった。The impedance of the resonator is determined by the number of electrode pairs of the IDT 2 and the crossing width W, that is, the length of the mutually crossing portions of the IDT electrodes. In order to obtain a resonator with high impedance, since the logarithm of the IDT 2 cannot be made very small in terms of the capacitance ratio γ, it is necessary to reduce the intersection width W. However, the grating reflector 3 constitutes a surface wave waveguide, and if the intersection width W is made smaller, the surface wave energy leaks from the waveguide region to the outside due to surface wave diffraction, which increases the Q of the resonator. There were some drawbacks that made it worse.
例えば、Ｑか低下した場合、７００回路では雑音レベル
に対する搬送波レベル（Ｃ／Ｎ）の劣化の原因となり、
共振子フィルタでは挿入損失が増加する原因となる。For example, if Q decreases, it will cause deterioration of the carrier wave level (C/N) relative to the noise level in the 700 circuit.
This causes an increase in insertion loss in a resonator filter.
（発明の目的）
本発明の目的は、共振子のＱを低下させることなくイン
ピーダンスを高くした弾性表面波共振子を提供すること
にある。(Object of the Invention) An object of the present invention is to provide a surface acoustic wave resonator with increased impedance without lowering the Q of the resonator.
（発明の構成および作用） 以下図面によって本発明の詳細な説明する。(Structure and operation of the invention) The present invention will be explained in detail below with reference to the drawings.
第２図は、本発明の第１の実施例を示す弾性表面波共振
子の電極構成の平面図であり、弾性表面波伝搬方向に２
つのＩＤＴ６，７を直列に配設して端子４，５間に電気
的に直列接続し、その両側にグレーティング反射器３を
配設した構成としている。第２図以降では圧電基板の図
示を省略する。FIG. 2 is a plan view of the electrode configuration of a surface acoustic wave resonator showing the first embodiment of the present invention, and shows two
Two IDTs 6 and 7 are arranged in series, electrically connected in series between terminals 4 and 5, and grating reflectors 3 are arranged on both sides. From FIG. 2 onwards, illustration of the piezoelectric substrate is omitted.
本発明による第２図の構成における２つのＩＤＴ６．７
の電極対数の和および交差幅Ｗを、第１図の従来の場合
と等しくした場合について、両者のインピーダンスの比
較を以下に述べる。Two IDTs 6.7 in the configuration of FIG. 2 according to the invention
A comparison of the impedances of the two will be described below when the sum of the number of electrode pairs and the crossing width W are made equal to those of the conventional case shown in FIG.
第２図の本発明の構成は、第１図の従来の構成のＩＤＴ
２を約２等分し端子４，５間に電気的に直列接続した場
合に相当する。第２図の各ＩＤＴ６．７の静電容量をそ
れぞれＣ８とすると、２一つのＩＤＴ６．７か直列に接
続されているので、端子４，５間の静電容量Ｃ２は％Ｃ
ｏとなる。これに対して第１図の共振子の端子４，５間
の静電容Ｉｔ Ｃ＋はＣ１−２ｃｏとなる。従って、Ｃ
，／Ｃ２＝４となり、インピーダンスを比へると第２図
の本発明の構成によるインピーダンスは第１図の従来の
構成のインピーダンスに対して４倍となる。第２図の第
１の実施例では、■端子対の端子４，５は共振子の片側
に設けられているか、第３図の第２の実施例のように端
子４，５を両側に設けることもてきる。The configuration of the present invention shown in FIG. 2 is similar to the conventional configuration of IDT shown in FIG.
This corresponds to the case where 2 is divided into approximately two equal parts and terminals 4 and 5 are electrically connected in series. If the capacitance of each IDT 6.7 in Fig. 2 is C8, two IDTs 6.7 are connected in series, so the capacitance C2 between terminals 4 and 5 is %C.
It becomes o. On the other hand, the capacitance It C+ between the terminals 4 and 5 of the resonator shown in FIG. 1 becomes C1-2co. Therefore, C
, /C2=4, and when comparing the impedances, the impedance according to the configuration of the present invention shown in FIG. 2 is four times that of the conventional configuration shown in FIG. In the first embodiment shown in Fig. 2, the terminals 4 and 5 of the terminal pair are provided on one side of the resonator, or as in the second embodiment shown in Fig. 3, the terminals 4 and 5 are provided on both sides. It can also happen.
第２図、第３図に示した本発明の第１及び第２の実施例
では、ＩＤＴは弾性表面波伝搬方向に直列・に２個配設
され電気的に直列接続された構成であるか、直列に配設
した３個以上のＩＤＴを電気的に直列接続した構成にし
てさらにインピーダンスを高くすることもてきる。In the first and second embodiments of the present invention shown in FIGS. 2 and 3, two IDTs are arranged in series in the surface acoustic wave propagation direction and electrically connected in series. It is also possible to further increase the impedance by using a configuration in which three or more IDTs arranged in series are electrically connected in series.
第４図は、本発明による第３の実施例を示す電極構成側
図であり、弾性表面波伝搬方向に３個の［）Ｔ８． ９
．１０を直列に配設し、その両側にグレーティング反射
器３を配設し、かつ、両側のＩＤＴ８と１０を電気的に
並列接続した１群（グループ）のＩＤＴと、中央のＩＤ
Ｔ９とを端子４，５間に直列ζこ接続した構成である。FIG. 4 is a side view of the electrode configuration showing a third embodiment of the present invention, in which three [)T8. 9
．． 10 are arranged in series, grating reflectors 3 are arranged on both sides, and IDTs 8 and 10 on both sides are electrically connected in parallel to form one group of IDTs, and an IDT in the center.
T9 is connected in series between terminals 4 and 5.
第４図のような構成とする二とにより、−ｒンピーダン
スを高くすると同時に縦方向に存在する縦１次モー１−
どＩＤＴとか電気的に結合しないようにすることかでき
ろ。With the configuration shown in Fig. 4, the -r impedance can be increased and at the same time the longitudinal first order modulus existing in the vertical direction can be reduced.
Is there a way to prevent electrical coupling between the IDT and the like?
（発明の効果）
以上詳細に説明したように、共振子のＱを低下させるこ
とな・（、すなわち共振子の交差幅を従来と同しにした
ままで、共振子のインピーダンスを高くすることかでき
るため、ＶＣＯに利用した場合周波数可変幅を広くする
ことかできる。また、挿入損失の増加を抑えた広帯域フ
ィルタを実現することかできる等その効果は極めて大き
い。(Effects of the invention) As explained in detail above, it is possible to increase the impedance of the resonator without lowering the Q of the resonator (that is, keeping the intersection width of the resonator the same as before). Therefore, when used in a VCO, it is possible to widen the frequency variable width.Also, the effects are extremely large, such as being able to realize a wideband filter that suppresses an increase in insertion loss.
第１図は従来の弾性表面波共振子構成側図、第２図〜第
４図は本発明の弾性表面波共振子の電極構成側図である
。
■・・・圧電基板、 ２． ６． ７． ８． ９．
ｔｏ・・・すたれ状変換器（Ｉｎｔｅｒｄｉｇｉｔａ
ｌ Ｔｒａｎｓｄｕｃｅｒ）、３・・・グレーティング
反射器、
４゜
５・・・端子。
代
理
人FIG. 1 is a side view of the configuration of a conventional surface acoustic wave resonator, and FIGS. 2 to 4 are side views of the electrode configuration of the surface acoustic wave resonator of the present invention. ■...Piezoelectric substrate, 2. 6. 7. 8. 9.
to... Interdigita
l Transducer), 3... Grating reflector, 4° 5... Terminal. agent
Claims (2)
た２つのグレーティング反射器の間に、電気信号を弾性
表面波に変換する複数個のすだれ状電極が弾性表面波伝
搬方向に直列に配設され、かつ、入出力端子間に電気的
に直列接続された弾性表面波共振子。(1) A plurality of interdigital electrodes that convert electrical signals into surface acoustic waves are arranged in series in the surface acoustic wave propagation direction between two grating reflectors provided on a piezoelectric substrate that propagates surface acoustic waves. A surface acoustic wave resonator that is installed and electrically connected in series between input and output terminals.
た２つのグレーティング反射器の間に、電気信号を弾性
表面波に変換する複数個のすだれ状電極が弾性表面波伝
搬方向に直列に配設され、該複数個のすだれ状電極が２
つ以上のグループによって構成され各グループ内のすだ
れ状電極が電気的に並列接続されるとともに、該２つ以
上のグループが入出力端子間に電気的に直列接続された
弾性表面波共振子。(2) A plurality of interdigital electrodes that convert electrical signals into surface acoustic waves are arranged in series in the surface acoustic wave propagation direction between two grating reflectors provided on the piezoelectric substrate that propagate surface acoustic waves. and the plurality of interdigital electrodes are
A surface acoustic wave resonator constituted by two or more groups, in which the interdigitated electrodes in each group are electrically connected in parallel, and the two or more groups are electrically connected in series between input and output terminals.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9734590A JPH03295308A (en) | 1990-04-12 | 1990-04-12 | Surface acoustic wave resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9734590A JPH03295308A (en) | 1990-04-12 | 1990-04-12 | Surface acoustic wave resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03295308A true JPH03295308A (en) | 1991-12-26 |
Family
ID=14189894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9734590A Pending JPH03295308A (en) | 1990-04-12 | 1990-04-12 | Surface acoustic wave resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03295308A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6801100B2 (en) | 1996-05-23 | 2004-10-05 | Matsushita Electric Industrial Co., Ltd. | Inter-digital transducer, surface acoustic wave filter and communication apparatus using the same |
| US20100052819A1 (en) * | 2008-09-02 | 2010-03-04 | Fujitsu Media Devices Limited | Acoustic wave device and system |
| CN103078603A (en) * | 2013-02-06 | 2013-05-01 | 中国电子科技集团公司第二十六研究所 | Surface acoustic wave filter with high power endurance |
| CN103117727A (en) * | 2013-02-06 | 2013-05-22 | 中国电子科技集团公司第二十六研究所 | High-impedance sound surface wave resonator |
-
1990
- 1990-04-12 JP JP9734590A patent/JPH03295308A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6801100B2 (en) | 1996-05-23 | 2004-10-05 | Matsushita Electric Industrial Co., Ltd. | Inter-digital transducer, surface acoustic wave filter and communication apparatus using the same |
| US20100052819A1 (en) * | 2008-09-02 | 2010-03-04 | Fujitsu Media Devices Limited | Acoustic wave device and system |
| US8289106B2 (en) * | 2008-09-02 | 2012-10-16 | Taiyo Yuden Co., Ltd. | Acoustic wave device and system |
| CN103078603A (en) * | 2013-02-06 | 2013-05-01 | 中国电子科技集团公司第二十六研究所 | Surface acoustic wave filter with high power endurance |
| CN103117727A (en) * | 2013-02-06 | 2013-05-22 | 中国电子科技集团公司第二十六研究所 | High-impedance sound surface wave resonator |
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