JPH04288719A - Surface acoustic wave device - Google Patents
Surface acoustic wave deviceInfo
- Publication number
- JPH04288719A JPH04288719A JP3295091A JP3295091A JPH04288719A JP H04288719 A JPH04288719 A JP H04288719A JP 3295091 A JP3295091 A JP 3295091A JP 3295091 A JP3295091 A JP 3295091A JP H04288719 A JPH04288719 A JP H04288719A
- Authority
- JP
- Japan
- Prior art keywords
- surface acoustic
- acoustic wave
- electrode
- input
- output
- 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.)
- Granted
Links
- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 126
- 239000000758 substrate Substances 0.000 claims description 12
- 239000004020 conductor Substances 0.000 claims description 9
- 230000008878 coupling Effects 0.000 claims description 9
- 238000010168 coupling process Methods 0.000 claims description 9
- 238000005859 coupling reaction Methods 0.000 claims description 9
- 230000001902 propagating effect Effects 0.000 abstract description 9
- 230000000644 propagated effect Effects 0.000 abstract description 3
- 230000005540 biological transmission Effects 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】この発明は、圧電体基板に、電気
信号を弾性表面波に変換する入力側電極と、上記入力側
電極により励振された弾性表面波を再び電気信号に変換
する出力側電極とを形成して構成された、フィルタ、遅
延線、および、共振器等の機能を有する弾性表面波装置
に関するものである。[Industrial Application Field] This invention provides a piezoelectric substrate with an input side electrode for converting an electric signal into a surface acoustic wave, and an output side for converting the surface acoustic wave excited by the input side electrode back into an electric signal. The present invention relates to a surface acoustic wave device having functions such as a filter, a delay line, and a resonator, which is configured by forming an electrode.
【０００２】0002
【従来の技術】図５は、例えば実開昭６３−９７９２０
号公報、あるいは、特開昭５７−１３５５１７号公報に
示された従来の弾性表面波装置を示す図である。図中、
１は圧電体基板であり、圧電体基板１の表面に入力側す
だれ状電極２、出力側すだれ状電極３とを構成している
。４は接地されたシールド電極であり、入力側すだれ状
電極２と出力側すだれ状電極３との間の圧電体基板１表
面に形成されている。[Prior Art] Fig. 5 shows, for example,
1 is a diagram showing a conventional surface acoustic wave device disclosed in Japanese Patent Laid-Open No. 57-135517. In the figure,
1 is a piezoelectric substrate, and an input side interdigital electrode 2 and an output side interdigital electrode 3 are formed on the surface of the piezoelectric substrate 1. Reference numeral 4 denotes a grounded shield electrode, which is formed on the surface of the piezoelectric substrate 1 between the input side interdigital electrode 2 and the output side interdigital electrode 3.
【０００３】入力側すだれ状電極２は、入力された電気
信号を弾性表面波に変換する。この弾性表面波への変換
を行う時に、入力側すだれ状電極の構成によって変換効
率に周波数特性をもたせることができる。出力側すだれ
状電極３は、入力側すだれ状電極２によって励振された
弾性表面波を受信し、再び、電気信号に変換する。この
場合にも、出力側すだれ状電極３の構成によって交換効
率に周波数特性をもたせることができる。このように、
入力側すだれ状電極２、および、出力側すだれ状電極３
における電気信号と弾性表面波との変換を介することに
よって、弾性表面波装置は様々な周波数特性のフィルタ
、遅延線、および、共振器等の機能を有することができ
る。[0003] The input-side interdigital electrode 2 converts an input electrical signal into a surface acoustic wave. When converting into a surface acoustic wave, the conversion efficiency can have frequency characteristics depending on the configuration of the input-side interdigital electrode. The output-side interdigital electrode 3 receives the surface acoustic wave excited by the input-side interdigital electrode 2, and converts it into an electric signal again. In this case as well, the configuration of the output-side interdigital electrode 3 allows the exchange efficiency to have frequency characteristics. in this way,
Input side interdigital electrode 2 and output side interdigital electrode 3
Through the conversion between an electric signal and a surface acoustic wave, the surface acoustic wave device can have functions such as filters, delay lines, and resonators with various frequency characteristics.
【０００４】シールド電極４がない場合には、図６に示
す等価回路のように、入力側すだれ状電極２と出力側す
だれ状電極３との間に、弾性表面波を介さないで、電気
的に直接結合する成分がある。このような電気的に直接
結合する成分は、入力すだれ状電極２と出力側すだれ状
電極３との間に存在するわずかな静電容量５によって、
弾性表面波への変換を介さないで、上記静電容量５を介
して出力側すだれ状電極３に直接結合するスプリアス成
分と考えることができる。このような不要なスプリアス
成分は電気的に結合する成分であるため、入力側すだれ
状電極２と出力側すだれ状電極３との間を弾性表面波の
伝搬速度で伝搬してくる弾性表面波と、入力側すだれ状
電極２から出力側すだれ状電極３に至るまでの所要時間
が著しく異なる。このため、弾性表面波を介して出力側
すだれ状電極３に伝搬してくる信号と、電気的に直接結
合するスプリアス成分とは、周波数に対する位相の変化
量が大きく異なるため、上記信号と上記スプリアス成分
とは、互いに干渉して弾性表面波装置の所要の特性を実
現できない。If there is no shield electrode 4, as shown in the equivalent circuit shown in FIG. There are components that bind directly to Such a component that is directly electrically coupled is caused by the slight capacitance 5 existing between the input interdigital electrode 2 and the output interdigital electrode 3.
It can be considered as a spurious component that is directly coupled to the output-side interdigital electrode 3 via the capacitance 5 without being converted into a surface acoustic wave. Since such unnecessary spurious components are components that are electrically coupled, the surface acoustic wave propagating between the input-side interdigital electrode 2 and the output-side interdigital electrode 3 at the propagation speed of the surface acoustic wave , the time required from the input side interdigital electrode 2 to the output side interdigital electrode 3 is significantly different. For this reason, the signal propagating to the output side interdigital electrode 3 via the surface acoustic wave and the electrically directly coupled spurious component have a large difference in phase change with respect to frequency. The components interfere with each other, making it impossible to achieve the desired characteristics of the surface acoustic wave device.
【０００５】上記の問題点を解決するため、従来のこの
種の弾性表面波装置では、入力側すだれ状電極２と出力
側すだれ状電極３との間に、図５、および図７に示すよ
うな接地したシールド電極４を構成していた。このシー
ルド電極４は、すだれ状電極を構成する金属薄膜と同じ
材質で構成され、入力側すだれ状電極２と出力側すだれ
状電極３との間に接地面を構成することにより、図７に
示す等価回路のように、それぞれ、入力側すだれ状電極
２と接地面との静電容量６、および、出力側すだれ状電
極３と接地面との静電容量７とすることができる。この
結果、入力側すだれ状電極２と出力側すだれ状電極３と
の間に存在していた静電容量５は極めて小さい値となり
、入力側すだれ状電極２と出力側すだれ状電極３との間
の弾性表面波を介さない電気的な結合が低減する。In order to solve the above-mentioned problems, in the conventional surface acoustic wave device of this type, a transducer is provided between the input side interdigital electrode 2 and the output side interdigital electrode 3 as shown in FIGS. 5 and 7. This constituted a grounded shield electrode 4. This shield electrode 4 is made of the same material as the metal thin film that constitutes the interdigital electrode, and by forming a ground plane between the input side interdigital electrode 2 and the output side interdigital electrode 3, as shown in FIG. As in the equivalent circuit, the capacitance 6 between the input-side interdigital electrode 2 and the ground plane, and the electrostatic capacitance 7 between the output-side interdigital electrode 3 and the ground plane can be respectively set. As a result, the capacitance 5 that existed between the input side interdigital electrode 2 and the output side interdigital electrode 3 becomes an extremely small value, and the capacitance 5 between the input side interdigital electrode 2 and the output side interdigital electrode 3 becomes extremely small. Electrical coupling not via surface acoustic waves is reduced.
【０００６】このとき、シールド電極４の構造は、シー
ルド電極４端面における弾性表面波の反射により、入力
側すだれ状電極２とシールド電極４との間、および、シ
ールド電極４と出力側すだれ状電極３との間に弾性表面
波の多重反射が生じないようにするために、図５に示し
たように、弾性表面波が伝搬する２か所の端面を、弾性
表面波の伝搬方向に垂直な方向に対して、傾斜させた構
造、すなわち、多くの場合には平行四辺形としていた。At this time, the structure of the shield electrode 4 is such that reflection of surface acoustic waves at the end face of the shield electrode 4 causes a gap between the input side interdigital electrode 2 and the shield electrode 4 and between the shield electrode 4 and the output side interdigital electrode. In order to prevent multiple reflections of surface acoustic waves from occurring between surface acoustic waves and The structure was tilted with respect to the direction, that is, in many cases, it was a parallelogram.
【０００７】[0007]
【発明が解決しようとする課題】しかし、従来のこの種
の弾性表面波装置のシールド電極においては、弾性表面
波の伝搬経路が、図８に示すように、弾性表面波の伝搬
する２か所のシールド電極４の端面への斜め入射に伴う
屈折のために、シールド電極４に入射する前の弾性表面
波の伝搬経路８とシールド電極４から伝搬してきた弾性
表面波の伝搬経路９とが間隔ｄだけずれる。このように
、屈折のために弾性表面波の位相速度の方向と群速度の
方向が異なり、シールド電極４から伝搬してきた弾性表
面波は、出力側すだれ状電極３に対して間隔ｄだけずれ
て入射するため、従来のこの種の弾性表面波装置では、
この弾性表面波の位相速度の方向と群速度の方向のずれ
による損失が増大し、所要の特性を実現できないという
問題点があった。[Problems to be Solved by the Invention] However, in the conventional shield electrode of this type of surface acoustic wave device, the propagation path of the surface acoustic wave is divided into two locations where the surface acoustic wave propagates, as shown in FIG. Due to the refraction caused by oblique incidence on the end face of the shield electrode 4, the propagation path 8 of the surface acoustic wave before entering the shield electrode 4 and the propagation path 9 of the surface acoustic wave propagating from the shield electrode 4 are separated by a distance. It shifts by d. In this way, the direction of the phase velocity and the direction of the group velocity of the surface acoustic wave are different due to refraction, and the surface acoustic wave propagating from the shield electrode 4 is shifted by the distance d with respect to the output side interdigital electrode 3. In conventional surface acoustic wave devices of this type,
There is a problem in that loss increases due to the deviation between the phase velocity direction and the group velocity direction of the surface acoustic wave, making it impossible to achieve desired characteristics.
【０００８】また、例えば特開昭５８−４３６０７号公
報に示されている弾性表面波フィルタの製造方法によれ
ば、弾性表面波装置は電気信号と弾性表面波とを変換す
るトランスジューサとしてアルミなどの金属のいわゆる
すだれ状電極を用いており、電極寸法がミクロン程度に
微細化してくると、圧電体基板上にすだれ状電極などを
形成する製造工程において、チャージがすだれ状電極の
狭いギャップを通して放電しすだれ状電極の破損が生じ
る。そこで、製造時には圧電体基板上のスクライブ領域
またはダイシング領域に放電防止用パターンを設けてお
き、後にこの放電防止用パターンを切断などにより除去
する作業を行っていた。[0008] Furthermore, according to a method for manufacturing a surface acoustic wave filter disclosed in, for example, Japanese Unexamined Patent Publication No. 58-43607, a surface acoustic wave device uses a transducer made of aluminum or the like for converting an electric signal and a surface acoustic wave. Metal interdigital electrodes are used, and as the electrode dimensions become finer to the micron level, charges are discharged through the narrow gaps of the interdigital electrodes during the manufacturing process of forming interdigital electrodes on piezoelectric substrates. Damage to the interdigital electrodes occurs. Therefore, during manufacturing, a discharge prevention pattern is provided in a scribe area or a dicing area on a piezoelectric substrate, and the discharge prevention pattern is later removed by cutting or the like.
【０００９】この発明は、係る問題点を解決するために
なされたものであり、シールド電極における弾性表面波
の伝搬方向のずれをなくすことにより、ずれによる損失
の低減を図り、かつ、スプリアス成分の低減された所要
の特性の弾性表面波装置を得ることを目的とする。また
、製造時のチャージによる電極の破損を防止でき、かつ
、使用時の切断が不必要で形成位置の自由度があり、か
つ、製造工数を削減できる弾性表面波装置を得ることを
目的とする。[0009] The present invention was made in order to solve this problem, and by eliminating the deviation in the propagation direction of surface acoustic waves in the shield electrode, it is possible to reduce the loss due to the deviation, and also to reduce the spurious component. The object is to obtain a surface acoustic wave device with reduced required characteristics. Another objective is to obtain a surface acoustic wave device that can prevent damage to the electrodes due to charging during manufacturing, eliminates the need for cutting during use, provides flexibility in formation position, and reduces manufacturing man-hours. .
【００１０】0010
【課題を解決するための手段】請求項１の弾性表面波装
置は、圧電体基板に形成され、電気信号を弾性表面波に
変換する入力側電極と、上記入力側電極により励振され
た弾性表面波を再び電気信号に変換する出力側電極と、
上記入力側電極と出力側電極との間の弾性表面波の伝搬
経路に形成され、上記入力側電極と出力側電極との電気
的結合を抑制するシールド電極とを有する弾性表面波装
置において、上記シールド電極を、弾性表面波のシール
ド電極への対応する入出力点における接線が互いに平行
となる一対の入出力端を上記接線を弾性表面波の伝搬方
向に対して傾斜させて複数配置し、それぞれの一対の入
出力端の通過による弾性表面波の伝搬経路のずれを相殺
するように構成したものである。[Means for Solving the Problems] A surface acoustic wave device according to claim 1 includes an input side electrode formed on a piezoelectric substrate and converting an electric signal into a surface acoustic wave, and an elastic surface excited by the input side electrode. an output electrode that converts the waves back into electrical signals;
In the surface acoustic wave device, the surface acoustic wave device includes a shield electrode formed in a propagation path of a surface acoustic wave between the input side electrode and the output side electrode, and suppressing electrical coupling between the input side electrode and the output side electrode. A plurality of shield electrodes are arranged with a pair of input/output ends such that tangent lines at corresponding input/output points of the surface acoustic wave to the shield electrode are parallel to each other, and the tangent lines are inclined with respect to the propagation direction of the surface acoustic wave. The structure is such that the shift in the propagation path of the surface acoustic wave due to passage through the pair of input and output ends is canceled out.
【００１１】また、請求項２の弾性表面波装置は、圧電
体基板に形成され、電気信号を弾性表面波に変換する入
力側電極と、上記入力側電極により励振された弾性表面
波を再び電気信号に変換する出力側電極と、上記入力側
電極と出力側電極との間の弾性表面波の伝搬経路に形成
され、上記入力側電極と出力側電極との電気的結合を抑
制する複数のシールド電極と、上記シールド電極と上記
入力側電極を構成する接地側導体とを接続する第１の高
抵抗線路と、上記第１の高抵抗線路が接続されていない
上記シールド電極と上記出力側電極を構成する接地側導
体とを接続する第２の高抵抗線路とを備えたものである
。The surface acoustic wave device according to claim 2 further includes an input side electrode formed on a piezoelectric substrate and converting an electric signal into a surface acoustic wave, and an input side electrode that converts the surface acoustic wave excited by the input side electrode into electricity again. A plurality of shields are formed in the propagation path of surface acoustic waves between an output side electrode that converts into a signal, and the input side electrode and the output side electrode, and suppress electrical coupling between the input side electrode and the output side electrode. a first high-resistance line connecting the electrode, the shield electrode and a ground conductor constituting the input-side electrode; and a first high-resistance line connecting the shield electrode and the output-side electrode to which the first high-resistance line is not connected. and a second high-resistance line that connects the constituent ground-side conductors.
【００１２】0012
【作用】請求項１の弾性表面波装置によれば、弾性表面
波のシールド電極への対応する入出力点における接線が
互いに平行となる一対の入出力端を上記接線を弾性表面
波の伝搬方向に対して傾斜させて複数配置し、それぞれ
の一対の入出力端の通過による弾性表面波の伝搬経路の
ずれを相殺するように構成したシールド電極に弾性表面
波が入射すると、シールド電極への入出力端で屈折して
伝搬する弾性表面波の要素は、最初の一対の入出力端の
通過による伝搬経路のずれが順次通過する一対の入出力
端の通過による伝搬経路のずれにより相殺されてシール
ド電極に入射する以前の伝搬方向と一致する方向に修正
されて出力側電極へ到達するため、シールド電極への入
出力端で屈折せずに伝搬する弾性表面波の要素を合致し
た経路で出力側電極へ到達させることができる。これに
より弾性表面波の要素である位相速度の方向と群速度の
方向のずれによる損失の増加を低減する。According to the surface acoustic wave device of claim 1, a pair of input and output ends in which tangents at corresponding input and output points to the shield electrode of the surface acoustic wave are parallel to each other, and the tangents are connected in the propagation direction of the surface acoustic wave. When a surface acoustic wave is incident on a plurality of shield electrodes arranged at an angle relative to each other and configured to cancel out the shift in the propagation path of the surface acoustic wave due to the passage of each pair of input and output ends, the incidence on the shield electrode is The surface acoustic wave element that is refracted and propagated at the output end is shielded because the deviation in the propagation path caused by passing through the first pair of input and output ends is canceled out by the deviation in the propagation path caused by passing through the successive pair of input and output ends. Since the propagation direction is corrected to match the propagation direction before entering the electrode and reaches the output side electrode, the surface acoustic wave elements that propagate without being refracted at the input and output ends of the shield electrode are transmitted along the matching path to the output side. It can be made to reach the electrode. This reduces the increase in loss due to the deviation between the direction of phase velocity and the direction of group velocity, which are elements of surface acoustic waves.
【００１３】また、請求項２の弾性表面波装置によれば
、シールド電極と入力側電極を構成する接地側導体とを
接続する第１の高抵抗線路と、シールド電極と出力側電
極を構成する接地側導体とを接続する第２の高抵抗線路
が製造時に入出力電極部分のチャージを逃すので製造時
のチャージによる入力側電極および出力側電極の破損を
防止し、かつ、高抵抗であるため使用時の切断を不要と
できる。さらに、使用時の切断が不必要であるため、第
１の高抵抗線路と第２の高抵抗線路の形成位置に自由度
がある。According to the surface acoustic wave device of claim 2, the first high-resistance line connects the shield electrode and the ground conductor constituting the input electrode, and the shield electrode and the output electrode constitute the first high resistance line. The second high-resistance line that connects the ground conductor releases the charge from the input and output electrodes during manufacturing, which prevents damage to the input and output electrodes due to charges during manufacturing, and because it has high resistance. Cutting during use is not necessary. Furthermore, since there is no need for cutting during use, there is flexibility in the formation positions of the first high resistance line and the second high resistance line.
【００１４】[0014]
【実施例】実施例１．図１は、この発明の弾性表面波装
置の一実施例を示す構成図であり、基本的なシールド電
極の構成の場合である。１〜３は従来のこの種の弾性表
面波装置と同様であり、１０ａは片側のシールド電極、
１０ｂはシールド電極１０ａと弾性表面波の伝搬方向に
垂直な軸に関して対称な構造のシールド電極である。こ
こで、シールド電極１０ａとシールド電極１０ｂは一対
の入出力端が互いに平行で弾性表面波の伝搬方向に対し
てそれぞれ逆向きに傾斜させて配置されたものである。[Example] Example 1. FIG. 1 is a block diagram showing an embodiment of the surface acoustic wave device of the present invention, and shows a basic shield electrode structure. 1 to 3 are similar to conventional surface acoustic wave devices of this type, and 10a is a shield electrode on one side;
10b is a shield electrode having a structure symmetrical to the shield electrode 10a with respect to an axis perpendicular to the propagation direction of surface acoustic waves. Here, a pair of input and output ends of the shield electrode 10a and the shield electrode 10b are arranged parallel to each other and inclined in opposite directions with respect to the propagation direction of the surface acoustic wave.
【００１５】次に動作について、図２を用いて説明する
。図２は、図１に示した実施例に動作の説明のための弾
性表面波の伝搬経路を合わせて示したものである。８は
入力側すだれ状電極２で励振されて、最初のシールド電
極１０ａに入射する弾性表面波の伝搬経路であり、９は
上記シールド電極１０ａから伝搬してきた弾性表面波の
伝搬経路である。また、９は同時に他方のシールド電極
１０ｂに入射する弾性表面波の伝搬経路でもある。１１
は他方のシールド電極１０ｂから出力側すだれ状電極３
に伝搬する弾性表面波の伝搬経路である。Next, the operation will be explained using FIG. 2. FIG. 2 shows the embodiment shown in FIG. 1 along with a propagation path of surface acoustic waves for explaining the operation. 8 is a propagation path of a surface acoustic wave excited by the input-side interdigital electrode 2 and incident on the first shield electrode 10a, and 9 is a propagation path of a surface acoustic wave propagated from the shield electrode 10a. Further, 9 is also a propagation path of a surface acoustic wave that simultaneously enters the other shield electrode 10b. 11
is from the other shield electrode 10b to the output side interdigital electrode 3
This is the propagation path of surface acoustic waves that propagate to .
【００１６】入力側すだれ状電極２で励振された弾性表
面波は、伝搬経路８を経て最初のシールド電極１０ａに
斜めに入射する。このとき、シールド電極１０ａに入射
する前と後とで弾性表面波の伝搬速度が異なるため、シ
ールド電極１０ａの端面にて弾性表面波が屈折する。そ
して、シールド電極１０ａの端面に達して再び屈折し、
伝搬経路９に沿って伝搬する。このとき、従来のこの種
の弾性表面波装置に多く見られるように、シールド電極
１０ａの形状が平行四辺形の場合、すなわち、シールド
電極１０ａの２か所の端面が互いに平行な場合には、シ
ールド電極１０ａへ入射前の伝搬経路８とシールド電極
１０ａから伝搬してきた伝搬経路９とは、互いに平行で
あり、かつ、位置が間隔ｄずれているのは従来のこの種
の弾性表面波装置と同様である。The surface acoustic wave excited by the input-side interdigital electrode 2 passes through the propagation path 8 and obliquely enters the first shield electrode 10a. At this time, since the propagation speed of the surface acoustic wave is different before and after the surface acoustic wave enters the shield electrode 10a, the surface acoustic wave is refracted at the end face of the shield electrode 10a. Then, it reaches the end face of the shield electrode 10a and is refracted again.
It propagates along the propagation path 9. At this time, when the shape of the shield electrode 10a is a parallelogram, as is often seen in conventional surface acoustic wave devices of this type, that is, when the two end faces of the shield electrode 10a are parallel to each other, The propagation path 8 before entering the shield electrode 10a and the propagation path 9 propagating from the shield electrode 10a are parallel to each other, and their positions are shifted by a distance d, unlike in conventional surface acoustic wave devices of this type. The same is true.
【００１７】しかし、この発明に係る弾性表面波装置で
は、さらに、弾性表面波の伝搬経路８、および、伝搬経
路９に垂直な軸に対して、最初に弾性表面波が入射した
シールド電極１０ａと対称な構造のシールド電極１０ｂ
を設けている。このとき、シールド電極１０ｂへ入射し
た弾性表面波の伝搬経路は、最初のシールド電極１０ａ
へ入射した弾性表面波の伝搬経路と反対方向へずれる経
路を経て、出力側すだれ状電極３へ至る。したがって、
出力側すだれ状電極３に入射する弾性表面波の伝搬方向
は、入力側すだれ状電極２で励振された弾性表面波の伝
搬方向と一致し、シールド電極１０での弾性表面波の屈
折による伝搬方向のずれは、互いに弾性表面波の伝搬方
向に垂直な軸に対称な構造のシールド電極１０ａ、１０
ｂを用いることにより、解消される。However, in the surface acoustic wave device according to the present invention, the shield electrode 10a on which the surface acoustic wave is first incident, and the axis perpendicular to the propagation path 8 and the propagation path 9 of the surface acoustic wave. Shield electrode 10b with symmetrical structure
has been established. At this time, the propagation path of the surface acoustic wave incident on the shield electrode 10b is the first shield electrode 10a.
It reaches the output-side interdigital electrode 3 through a path that is deviated in the opposite direction to the propagation path of the surface acoustic wave incident on the surface acoustic wave. therefore,
The propagation direction of the surface acoustic wave incident on the output side interdigital electrode 3 coincides with the propagation direction of the surface acoustic wave excited by the input side interdigital electrode 2, and the propagation direction due to refraction of the surface acoustic wave at the shield electrode 10. The difference between the shield electrodes 10a and 10, which have a structure symmetrical to each other with respect to an axis perpendicular to the propagation direction of surface acoustic waves.
This can be solved by using b.
【００１８】なお、弾性表面波が伝搬するシールド電極
の入出力端は、直線ではなく曲線の場合でも、弾性表面
波のシールド電極への対応する入出力点における接線が
互いに平行となる一対の入出力端であればよく、上記接
線を弾性表面波の伝搬方向に対して傾斜させて複数配置
し、それぞれの一対の入出力端の通過による弾性表面波
の伝搬経路のずれを相殺するように構成すれば上記実施
例１と同様の効果を得ることができる。また、シールド
電極の一対の入出力端の通過による弾性表面波の伝搬経
路のずれ量は圧電体基板とシールド電極の材質を一定と
した場合には一対の入出力端の間隔および弾性表面波の
伝搬方向に対する入出力端接線の傾斜角度の関数となる
ため、これらにより設定できる。次にシールド電極の構
成例を示す。[0018] Even if the input and output ends of the shield electrode through which the surface acoustic wave propagates are not straight lines but curves, there is a pair of input and output ends in which the tangents at the corresponding input and output points of the surface acoustic wave to the shield electrode are parallel to each other. It may be any output end, and a plurality of them are arranged so that the tangent line is inclined with respect to the propagation direction of the surface acoustic wave, and the configuration is such that the deviation of the propagation path of the surface acoustic wave due to passage of each pair of input and output ends is canceled out. By doing so, the same effect as in the first embodiment can be obtained. In addition, when the materials of the piezoelectric substrate and the shield electrode are constant, the amount of deviation in the propagation path of the surface acoustic wave due to the passage of the pair of input and output ends of the shield electrode is determined by the distance between the pair of input and output ends and the amount of deviation of the surface acoustic wave Since it is a function of the inclination angle of the input/output end tangent to the propagation direction, it can be set using these. Next, an example of the structure of the shield electrode will be shown.
【００１９】実施例２．図３は上記実施例１におけるシ
ールド電極の他の実施例を示す構成図である。ここでは
シールド電極の部分のみを示している。Example 2. FIG. 3 is a configuration diagram showing another embodiment of the shield electrode in the first embodiment. Only the shield electrode portion is shown here.
【００２０】なお、この発明はこれらに限らず、３個以
上の複数個のシールド電極で構成した場合にも適用でき
る。さらに、上記実施例１および実施例２は、それぞれ
１個の入力側すだれ状電極と１個の出力側すだれ状電極
とからなる弾性表面波装置の例について説明したが、複
数個の入力側すだれ状電極と、複数個の出力側すだれ状
電極とからなる弾性表面波装置にも適用できる。[0020] The present invention is not limited to these, but can also be applied to a structure composed of three or more shield electrodes. Furthermore, in the first and second embodiments described above, examples of surface acoustic wave devices including one input-side interdigital electrode and one output-side interdigital electrode have been described, but a plurality of input-side interdigital The present invention can also be applied to a surface acoustic wave device comprising a shaped electrode and a plurality of output-side interdigital electrodes.
【００２１】実施例３．図４はこの発明の弾性表面波装
置の他の実施例を示す構成図であり、図１に示した実施
例の構成において適用した例を示す。図において、１２
はシールド電極１０ａと入力側すだれ状電極２を構成す
る接地側導体とを接続する第１の高抵抗線路、１３は上
記第１の高抵抗線路１２が接続されていないシールド電
極１０ｂと出力側すだれ状電極３を構成する接地側導体
とを接続する第２の高抵抗線路である。Example 3. FIG. 4 is a block diagram showing another embodiment of the surface acoustic wave device of the present invention, and shows an example in which the structure of the embodiment shown in FIG. 1 is applied. In the figure, 12
13 is a first high-resistance line connecting the shield electrode 10a and the ground conductor constituting the input-side interdigital transducer 2, and 13 is the output-side interdigital interdigitator and the shield electrode 10b to which the first high-resistance line 12 is not connected. This is a second high-resistance line that connects the ground-side conductor constituting the shaped electrode 3.
【００２２】上記の構成によれば、第１の高抵抗線路１
２および第２の高抵抗線路１３はそれぞれ接地導体どお
しを高抵抗で接続するものであり製造時にチャージを逃
す。さらに、シールド電極１０ａとシールド電極１０ｂ
とは分離されていて入力側すだれ状電極２と出力側すだ
れ状電極３の結合を生じさせないため使用時の切断が不
要であり、したがって形成位置に自由度がある。According to the above configuration, the first high resistance line 1
2 and the second high-resistance line 13 connect the ground conductors with each other with high resistance, and allow charge to escape during manufacturing. Furthermore, the shield electrode 10a and the shield electrode 10b
Since the input-side interdigital electrode 2 and the output-side interdigital electrode 3 are separated from each other and do not cause coupling between the input-side interdigital electrode 2 and the output-side interdigital electrode 3, there is no need for cutting during use, and therefore there is a degree of freedom in the formation position.
【００２３】[0023]
【発明の効果】以上のように請求項１の弾性表面波装置
によれは、シールド電極を、一対の入出力端を複数配置
し、それぞれの一対の入出力端の通過による弾性表面波
の伝搬回路のずれを相殺するように構成したので、弾性
表面波の伝搬経路のずれによる損失の増加が低減された
、入力側電極と出力側電極との電気的結合が抑制された
弾性表面波装置を得られる効果がある。また、請求項２
の弾性表面波装置によれば、第１の高抵抗線路と第２の
高抵抗線路は製造時のチャージによる入力側電極および
出力側電極の破損を防止し、かつ、使用時の切断が不必
要であるので、弾性表面波装置の電極パターン設計の自
由度が増すとともに製造工数を削減できる効果がある。As described above, according to the surface acoustic wave device of claim 1, the shield electrode is arranged with a plurality of pairs of input and output ends, and the surface acoustic wave propagates by passing through each pair of input and output ends. The surface acoustic wave device is configured to cancel circuit deviations, thereby reducing the increase in loss due to deviations in the propagation path of the surface acoustic wave, and suppressing electrical coupling between the input side electrode and the output side electrode. There are benefits to be gained. Also, claim 2
According to this surface acoustic wave device, the first high-resistance line and the second high-resistance line prevent damage to the input-side electrode and output-side electrode due to charging during manufacturing, and do not require cutting during use. Therefore, there is an effect that the degree of freedom in designing the electrode pattern of the surface acoustic wave device is increased and the number of manufacturing steps can be reduced.
【図１】この発明による弾性表面波装置の実施例１を示
す構成図である。FIG. 1 is a configuration diagram showing a first embodiment of a surface acoustic wave device according to the present invention.
【図２】この発明による弾性表面波装置の実施例１によ
る弾性表面波の伝搬方向を示す説明図である。FIG. 2 is an explanatory diagram showing the propagation direction of surface acoustic waves according to Example 1 of the surface acoustic wave device according to the present invention.
【図３】この発明による弾性表面波装置の実施例２を示
すシールド電極の構成図である。FIG. 3 is a configuration diagram of a shield electrode showing a second embodiment of the surface acoustic wave device according to the present invention.
【図４】この発明による弾性表面波装置の実施例３を示
す構成図である。FIG. 4 is a configuration diagram showing a third embodiment of a surface acoustic wave device according to the present invention.
【図５】従来のこの種の弾性表面波装置を示す構成図で
ある。FIG. 5 is a configuration diagram showing a conventional surface acoustic wave device of this type.
【図６】シールド電極を有しない弾性表面波装置におけ
る入力側すだれ状電極と出力側すだれ状電極との間の電
気的な結合を示す等価回路図である。FIG. 6 is an equivalent circuit diagram showing electrical coupling between an input-side interdigital electrode and an output-side interdigital electrode in a surface acoustic wave device without a shield electrode.
【図７】シールド電極を有する弾性表面波装置における
入力側すだれ状電極と出力側すだれ状電極との間の電気
的な結合を示す等価回路図である。FIG. 7 is an equivalent circuit diagram showing electrical coupling between an input side interdigital electrode and an output side interdigital electrode in a surface acoustic wave device having a shield electrode.
【図８】従来のこの種の弾性表面波装置の弾性表面波の
伝搬方向を示す説明図である。FIG. 8 is an explanatory diagram showing the propagation direction of surface acoustic waves in a conventional surface acoustic wave device of this type.
１ 圧電体基板 ２ 入力側すだれ状電極 ３ 出力側すだれ状電極 ４ シールド電極 ５ 静電容量 ６ 静電容量 ７ 静電容量 ８ 伝搬経路 ９ 伝搬径路 １０ シールド電極 １０ａ シールド電極 １０ｂ シールド電極 １１ 伝搬経路 １２ 第１の高抵抗線路 １３ 第２の高抵抗線路 1 Piezoelectric substrate 2 Input side interdigital electrode 3 Output side interdigital electrode 4 Shield electrode 5 Capacitance 6 Capacitance 7. Capacitance 8 Propagation path 9 Propagation path 10 Shield electrode 10a Shield electrode 10b Shield electrode 11 Propagation path 12 First high resistance line 13 Second high resistance line
Claims (2)
性表面波に変換する入力側電極と、上記入力側電極によ
り励振された弾性表面波を再び電気信号に変換する出力
側電極と、上記入力側電極と出力側電極との間の弾性表
面波の伝搬経路に形成され、上記入力側電極と出力側電
極との電気的結合を抑制するシールド電極とを有する弾
性表面波装置において、上記シールド電極を、弾性表面
波のシールド電極への対応する入出力点における接線が
互いに平行となる一対の入出力端を上記接線を弾性表面
波の伝搬方向に対して傾斜させて複数配置し、それぞれ
の一対の入出力端の通過による弾性表面波の伝搬経路の
ずれを相殺するように構成したことを特徴とする弾性表
面波装置。1. An input side electrode that is formed on a piezoelectric substrate and converts an electric signal into a surface acoustic wave; an output side electrode that converts the surface acoustic wave excited by the input side electrode back into an electric signal; A surface acoustic wave device comprising a shield electrode formed in a propagation path of a surface acoustic wave between an input side electrode and an output side electrode, and suppressing electrical coupling between the input side electrode and the output side electrode. A plurality of electrodes are arranged with a pair of input/output ends such that the tangents at the corresponding input/output points to the surface acoustic wave shield electrode are parallel to each other, and the tangents are inclined with respect to the propagation direction of the surface acoustic wave. 1. A surface acoustic wave device characterized in that the surface acoustic wave device is configured to cancel a deviation in a propagation path of a surface acoustic wave caused by passage through a pair of input and output ends.
性表面波に変換する入力側電極と、上記入力側電極によ
り励振された弾性表面波を再び電気信号に変換する出力
側電極と、上記入力側電極と出力側電極との間の弾性表
面波の伝搬経路に形成され、上記入力側電極と出力側電
極との電気的結合を抑制する複数のシールド電極と、上
記シールド電極と上記入力側電極を構成する接地側導体
とを接続する第１の高抵抗線路と、上記第１の高抵抗線
路が接続されていない上記シールド電極と上記出力側電
極を構成する接地側導体とを接続する第２の高抵抗線路
とを備えたことを特徴とする弾性表面波装置。2. An input side electrode formed on a piezoelectric substrate and converting an electric signal into a surface acoustic wave; an output side electrode converting the surface acoustic wave excited by the input side electrode back into an electric signal; a plurality of shield electrodes formed in a propagation path of surface acoustic waves between the input side electrode and the output side electrode to suppress electrical coupling between the input side electrode and the output side electrode; and the shield electrode and the input side electrode. A first high-resistance line that connects a ground-side conductor that constitutes an electrode, and a first high-resistance line that connects the shield electrode to which the first high-resistance line is not connected and a ground-side conductor that constitutes the output electrode. 2. A surface acoustic wave device comprising: 2 high resistance lines.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3032950A JP3013464B2 (en) | 1991-02-27 | 1991-02-27 | Surface acoustic wave device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3032950A JP3013464B2 (en) | 1991-02-27 | 1991-02-27 | Surface acoustic wave device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04288719A true JPH04288719A (en) | 1992-10-13 |
| JP3013464B2 JP3013464B2 (en) | 2000-02-28 |
Family
ID=12373223
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3032950A Expired - Lifetime JP3013464B2 (en) | 1991-02-27 | 1991-02-27 | Surface acoustic wave device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3013464B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004054102A1 (en) * | 2002-12-10 | 2004-06-24 | Nortel Networks Limited | Surface wave devices with low passband ripple |
| WO2006118039A1 (en) * | 2005-04-27 | 2006-11-09 | Matsushita Electric Industrial Co., Ltd. | Antenna sharing device |
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|---|---|---|---|---|
| JPS5178669A (en) * | 1974-12-28 | 1976-07-08 | Toko Inc | DANSEIHYOMENHAFUIRUTAANO SEIZOHOHO |
| JPS5183444A (en) * | 1975-01-18 | 1976-07-22 | Toko Inc | DANSEIHYOMENHAFUIRUTAA |
| JPS5572337U (en) * | 1978-11-08 | 1980-05-19 | ||
| JPS62181036U (en) * | 1986-05-09 | 1987-11-17 |
-
1991
- 1991-02-27 JP JP3032950A patent/JP3013464B2/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5178669A (en) * | 1974-12-28 | 1976-07-08 | Toko Inc | DANSEIHYOMENHAFUIRUTAANO SEIZOHOHO |
| JPS5183444A (en) * | 1975-01-18 | 1976-07-22 | Toko Inc | DANSEIHYOMENHAFUIRUTAA |
| JPS5572337U (en) * | 1978-11-08 | 1980-05-19 | ||
| JPS62181036U (en) * | 1986-05-09 | 1987-11-17 |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004054102A1 (en) * | 2002-12-10 | 2004-06-24 | Nortel Networks Limited | Surface wave devices with low passband ripple |
| US6856214B2 (en) * | 2002-12-10 | 2005-02-15 | Nortel Networks Limited | Surface wave devices with low passband ripple |
| US7023300B2 (en) * | 2002-12-10 | 2006-04-04 | Chun-Yun Jian | Surface wave devices with low passband ripple |
| WO2006118039A1 (en) * | 2005-04-27 | 2006-11-09 | Matsushita Electric Industrial Co., Ltd. | Antenna sharing device |
| JP2006311041A (en) * | 2005-04-27 | 2006-11-09 | Matsushita Electric Ind Co Ltd | Antenna duplexer |
| EP1883159A1 (en) * | 2005-04-27 | 2008-01-30 | Matsushita Electric Industrial Co., Ltd. | Antenna sharing device |
| EP1883159A4 (en) * | 2005-04-27 | 2009-12-23 | Panasonic Corp | Antenna sharing device |
| US7733196B2 (en) | 2005-04-27 | 2010-06-08 | Panasonic Corporation | Antenna sharing device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3013464B2 (en) | 2000-02-28 |
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