JPS6143311Y2 - - Google Patents
Info
- Publication number
- JPS6143311Y2 JPS6143311Y2 JP1976131746U JP13174676U JPS6143311Y2 JP S6143311 Y2 JPS6143311 Y2 JP S6143311Y2 JP 1976131746 U JP1976131746 U JP 1976131746U JP 13174676 U JP13174676 U JP 13174676U JP S6143311 Y2 JPS6143311 Y2 JP S6143311Y2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- surface acoustic
- acoustic wave
- different
- frequency
- 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.)
- Expired
Links
- 238000010897 surface acoustic wave method Methods 0.000 claims description 44
- 239000010409 thin film Substances 0.000 claims description 4
- 230000000737 periodic effect Effects 0.000 claims description 3
- 239000000758 substrate Substances 0.000 description 5
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Description
【考案の詳細な説明】
本考案は弾性表面波装置の構造に関するもの
で、特に分波器等として用いるのに適した弾性表
面波装置に関するものである。[Detailed Description of the Invention] The present invention relates to the structure of a surface acoustic wave device, and particularly to a surface acoustic wave device suitable for use as a duplexer or the like.
弾性表面波装置は、圧電性の基板上に交叉櫛形
電極を設けて弾性表面波を励振させるものであ
る。交叉櫛形電極によつて励振される弾性表面波
は、交叉櫛形電極の電極指の長手方向に対して直
角の方向に伝播するが、電極の端部ではこれと伝
播方向が異なる弾性表面波が励振される。この弾
性表面波の伝播方向は、電極指の長手方向に直角
の方向から一定の角度を有しており、周波数も電
極指の間隔によつて定まる中心周波数とは異なつ
たものである。 A surface acoustic wave device excites surface acoustic waves by providing interdigitated electrodes on a piezoelectric substrate. The surface acoustic waves excited by the interdigitated electrodes propagate in a direction perpendicular to the longitudinal direction of the electrode fingers of the interdigitated electrodes, but surface acoustic waves with a different propagation direction are excited at the ends of the electrodes. be done. The propagation direction of this surface acoustic wave has a certain angle from the direction perpendicular to the longitudinal direction of the electrode fingers, and the frequency is also different from the center frequency determined by the spacing between the electrode fingers.
この現象は次の理由によるものである。弾性表
面波を交叉櫛形電極で励振する場合、弾性表面波
は交叉櫛形電極の電極指の長手方向に直角な方向
と平行な方向との成分によつて伝播方向が決定さ
れる。通常の交叉櫛形電極では直角方向の成分が
大部分であるので電極指の長手方向に直角の方向
に伝播するが、端部では平行方向の成分が強くな
るので異なる伝播方向となるものである。このこ
とから、直角方向の成分と平行方向の成分とを合
成して任意の周波数の弾性表面波を電極指の長手
方向に直角な方向からある角度をもつて伝播させ
ることができる。 This phenomenon is due to the following reasons. When a surface acoustic wave is excited by a crossed comb electrode, the propagation direction of the surface acoustic wave is determined by components in a direction perpendicular to and parallel to the longitudinal direction of the electrode fingers of the crossed comb electrode. In a normal crossed comb electrode, most of the components are in the perpendicular direction, so the propagation occurs in a direction perpendicular to the longitudinal direction of the electrode fingers, but at the ends, the parallel component becomes stronger, so the propagation direction is different. Therefore, by combining the orthogonal component and the parallel component, surface acoustic waves of any frequency can be propagated at a certain angle from a direction perpendicular to the longitudinal direction of the electrode finger.
考案者は、上記の現象を利用して交叉櫛形電極
に周期性を持たせることを考え、これによつて周
期波源を形成して伝播方向の異なる弾性表面波を
強める方法を考えた。交叉櫛形電極に周期性を持
たせると、特定の周波数において弾性表面波の電
極指の長手方向に平行な方向の成分が強くなり、
それによつてその周波数の弾性表面波が中心周波
数と異なる一定の方向に伝播することを利用する
ものである。 The inventor considered making use of the above phenomenon to impart periodicity to the interdigitated comb-shaped electrodes, thereby creating a periodic wave source and devising a method of intensifying surface acoustic waves in different propagation directions. When periodicity is imparted to the interdigitated electrodes, the component of the surface acoustic wave in the direction parallel to the longitudinal direction of the electrode fingers becomes stronger at a specific frequency.
This makes use of the fact that surface acoustic waves of that frequency propagate in a fixed direction different from the center frequency.
電極に周期性を持たせるためには次の方法があ
る。従来使用されている交叉櫛形電極に圧電体の
薄膜を介して交叉櫛形電極の電極指を横切る方向
に伸びる細条片の電極を対向させて、これによつ
て交叉櫛形電極を実質的に分割して周期性を持た
せるものである。細条片の電極が対向する部分で
は結合係数が大きくなるので弾性表面波の振幅が
大きくなり、細条片の電極が対向しない部分では
弾性表面波を励振しないかあるいは振幅が非常に
小さくなる。このように、電気−機械結合係数の
大きな部分と小さな部分を形成し、これによつて
電極を実質的に分割して周期性を持たせるもので
ある。 There are the following methods to give periodicity to the electrodes. A conventionally used cross-comb electrode is opposed to it by a strip of electrode extending in a direction transverse to the electrode fingers of the cross-comb electrode through a piezoelectric thin film, thereby substantially dividing the cross-comb electrode. This gives periodicity. In the part of the strip where the electrodes face each other, the coupling coefficient becomes large, so the amplitude of the surface acoustic wave becomes large, and in the part of the strip where the electrodes do not face, the surface acoustic wave is not excited or the amplitude is very small. In this way, a portion with a large electromechanical coupling coefficient and a portion with a small electromechanical coupling coefficient are formed, thereby substantially dividing the electrode and imparting periodicity.
上記のような周期性を有する交叉櫛形電極に入
力電気信号が加わると弾性表面波が励振される。
交叉櫛形電極の電極指の間隔によつて中心周波数
は決まるが、中心周波数とは異なる周波数の弾性
表面波が分割された交叉櫛形電極の各部分から発
生し、中心周波数の弾性表面波の伝播方向と異な
る一定の方法に伝播して行く。 When an input electrical signal is applied to the interdigitated interdigitated electrodes having periodicity as described above, surface acoustic waves are excited.
The center frequency is determined by the spacing between the electrode fingers of the interdigitated electrode, but surface acoustic waves with a frequency different from the center frequency are generated from each section of the intersected interdigitated electrode, and the propagation direction of the surface acoustic wave of the center frequency and propagate in different ways.
このように、周期波源によつて特定の周波数の
弾性表面波を特定の方向に伝播させることができ
るが、この弾性表面波は波源の周期を適当に選択
することによつてその周波数と伝播方向を任意に
とることができる。これを利用して、特定の周波
数の信号を取り出しまたは除去することができ
る。 In this way, a surface acoustic wave of a specific frequency can be propagated in a specific direction by a periodic wave source, but the frequency and propagation direction of this surface acoustic wave can be controlled by appropriately selecting the period of the wave source. can be taken arbitrarily. This can be used to extract or remove signals of specific frequencies.
本考案は、上記の原理を利用して、従来になか
つた弾性表面波装置によつて、分波器等として利
用価値の高い装置を得ることを目的とする。 The object of the present invention is to utilize the above-mentioned principle to obtain a device with high utility value as a duplexer, etc., using a surface acoustic wave device that has not existed in the past.
本考案による弾性表面波装置を図面に従つて説
明する。 A surface acoustic wave device according to the present invention will be explained according to the drawings.
第１図は本考案の一実施例の部分斜視図で一部
切欠してある。入力電極部のみを示してあるが、
実際の装置においては基板は広い面積を有し、所
定の位置に複数の出力電極を具えている。絶縁性
の基板１１上に金属の細条片による電極１２を設
けるが、一部の電極１２ａと他の電極１２ｂとの
幅が異なるようにする。すなわち電極１２ａの
各々の幅W1と電極１２ｂの幅W2とを異ならせそ
れぞれの部分の周期を変えた構造となつている。
圧電性の薄膜１３を介して電極１２と対向する位
置に交叉櫛形電極１４を設ける。細条片の電極１
２と交叉櫛形電極１４の電極指とが直交する構造
となつている。 FIG. 1 is a partial perspective view of an embodiment of the present invention, with a portion cut away. Although only the input electrode part is shown,
In an actual device, the substrate has a large area and includes a plurality of output electrodes at predetermined positions. Electrodes 12 made of metal strips are provided on an insulating substrate 11, with some electrodes 12a having different widths from other electrodes 12b. That is, the structure is such that the width W 1 of each electrode 12a and the width W 2 of the electrode 12b are different, and the period of each portion is changed.
A crossed comb-shaped electrode 14 is provided at a position facing the electrode 12 with a piezoelectric thin film 13 interposed therebetween. Strip electrode 1
2 and the electrode fingers of the crossed comb-shaped electrode 14 are perpendicular to each other.
電極１２によつて交叉櫛形電極１４は周期性を
有するようになるが、単一の周期ではなく電極１
２ａの部分と電極１２ｂの部分で異なる周期の部
分が形成される。中心周波数は全体にわたつて同
じであるが、周期が異なることによつて電極１２
ａの部分から電極１２ａに平行な方向から一定の
角度をもつて伝播する中心周波数と異なる周波数
の弾性表面波と、電極１２ｂの部分から電極１２
ｂに平行な方向から一定の角度をもつて伝播する
中心周波数と異なる周波数の弾性表面波がそれぞ
れ励振される。それらの二種の弾性表面波は周波
数及び伝播方向が異なる。これは、二つの部分で
周期性が異なるので前記の二方向の成分の現れ方
が異なり、これによつて周波数、伝播方向が異な
るようになる。 The electrode 12 causes the interdigitated electrode 14 to have periodicity, but instead of a single period, the electrode 1
Portions with different periods are formed in the portion 2a and the portion of the electrode 12b. Although the center frequency is the same throughout, the period differs so that the electrode 12
A surface acoustic wave with a frequency different from the center frequency propagates at a certain angle from a direction parallel to the electrode 12a from the part a, and a surface acoustic wave with a frequency different from the center frequency propagating from the part a to the electrode 12b
Surface acoustic waves with frequencies different from the center frequency that propagate at a constant angle from a direction parallel to b are excited. The two types of surface acoustic waves differ in frequency and propagation direction. This is because the two parts have different periodicities, so the components in the two directions appear differently, and as a result, the frequencies and propagation directions differ.
なお、第１図では出力電極は図示されていない
が、基板１１は交叉櫛形電極１４の電極指の長手
方向に直角な方向だけでなくその両側に広がりを
持つている。そして、中心周波数の弾性表面波の
伝播方向と異なる方向の所定の位置に出力電極が
二つ以上形成されている。 Although the output electrodes are not shown in FIG. 1, the substrate 11 extends not only in a direction perpendicular to the longitudinal direction of the electrode fingers of the interdigitated electrodes 14 but also on both sides thereof. Two or more output electrodes are formed at predetermined positions in a direction different from the propagation direction of the surface acoustic wave of the center frequency.
中心周波数と周波数及び伝播方向の異なるそれ
ぞれの弾性表面波は、入力信号にそれぞれの周波
数の信号が印加されたときにその周波数の弾性表
面波を所定の方向に励振する。この伝播方向は交
叉櫛形電極の電極指の間隔と前記の周期によつて
決定される。 When a signal of each frequency is applied to the input signal, each surface acoustic wave having a different center frequency, frequency, and propagation direction excites the surface acoustic wave of that frequency in a predetermined direction. This direction of propagation is determined by the spacing between the electrode fingers of the interdigitated electrodes and the period.
本考案は上記の例のみに限られるものではな
く、周期の変化を三通り以上にする等種々の変形
をなすことができる。また、交互櫛形電極の中心
周波数を各電極部分ごとに変化させても良い。こ
のようにして、周波数の異なつた弾性表面波を、
異なつた方向に励振し、これを出力電極で電気信
号に変換することができる。 The present invention is not limited to the above example, and can be modified in various ways, such as changing the period in three or more ways. Further, the center frequency of the alternating comb-shaped electrodes may be changed for each electrode portion. In this way, surface acoustic waves with different frequencies can be
It can be excited in different directions and converted into an electrical signal at the output electrode.
本考案による弾性表面波装置は分波器等として
利用できる。第２図のように、入力電極２５に対
してその交叉櫛形電極の電極指の長手方向に直角
な方向から所定の角度を有する方向に出力電極２
６，２７を設ける。出力電極２６は中心周波数の
弾性表面波の伝播方向からθ１だけ角度を有する
方向に、出力電極２７はθ２だけ角度を有する方
向に設けられている。出力電極２６と出力電極２
７は異なる周波数の所定の弾性表面波のみに応答
するようにしたものである。 The surface acoustic wave device according to the present invention can be used as a duplexer, etc. As shown in FIG. 2, the output electrode 2 is oriented at a predetermined angle from the direction perpendicular to the longitudinal direction of the electrode fingers of the interdigitated electrode 25 with respect to the input electrode 25.
6, 27 are provided. The output electrode 26 is provided in a direction having an angle of θ 1 from the propagation direction of the surface acoustic wave at the center frequency, and the output electrode 27 is provided in a direction having an angle of θ 2 from the propagation direction of the surface acoustic wave of the center frequency. Output electrode 26 and output electrode 2
7 is designed to respond only to predetermined surface acoustic waves of different frequencies.
このように、中心周波数に対して異なつた一定
の周波数の弾性表面波の伝播方向に出力電極を設
けてこの弾性表面波を受信できるので、精度の高
い弾性表面波装置が得られる。入力電極の周期の
変化を多くしてそれに応じた出力電極を多数設け
てそれぞれの周波数成分を取り出すこともでき
る。また、逆に一定の周波数の弾性表面波を除去
することも可能となり、これらを組み合わせるこ
とによつて種々の装置ができる。 In this way, since the output electrode can be provided in the propagation direction of surface acoustic waves having a fixed frequency different from the center frequency and can receive the surface acoustic waves, a highly accurate surface acoustic wave device can be obtained. It is also possible to increase the change in the period of the input electrode and provide a correspondingly large number of output electrodes to extract each frequency component. Conversely, it is also possible to remove surface acoustic waves of a certain frequency, and by combining these, various devices can be created.
このように、本考案による弾性表面波装置は波
源に周期性を持たせるだけでなく、周期性に変化
をつけることによつて周波数特性を変化させるこ
とができる。しかも、複雑な装置が不要で電極の
構造と配置のみによつてそれがなし得る。したが
つて、製造も容易で小型化できる長所も有してい
る。 In this way, the surface acoustic wave device according to the present invention can not only provide periodicity to the wave source, but also change the frequency characteristics by varying the periodicity. Furthermore, this can be achieved only by the structure and arrangement of the electrodes without the need for complicated equipment. Therefore, it also has the advantage of being easy to manufacture and miniaturized.
第１図は本考案の実施例の部分斜視図で一部切
欠したもの、第２図は本考案の他の実施例の平面
図を示す。
１１……基板、１２……電極、１３……圧電性
薄膜、１４……交叉櫛形電極。
FIG. 1 is a partially cutaway partial perspective view of an embodiment of the present invention, and FIG. 2 is a plan view of another embodiment of the present invention. DESCRIPTION OF SYMBOLS 11... Substrate, 12... Electrode, 13... Piezoelectric thin film, 14... Cross-comb electrode.
Claims (1)
極を組み合わせた周期波源を有する弾性表面波装
置において、該細条片の電極の一部をなす複数の
電極の幅が他の部分の複数の電極の幅と異なるよ
うに形成され、電極指の間隔によつて決まる電極
指の長手方向に直角な方向に伝播する中心周波数
の弾性表面波と異なる二以上の周波数の弾性表面
波を該中心周波数の弾性表面波の伝播方向と異な
る方向に励振することを特徴とする弾性表面波装
置。 In a surface acoustic wave device having a periodic wave source in which a strip electrode is combined with a cross-comb electrode via a piezoelectric thin film, the width of the plurality of electrodes forming a part of the strip electrode is the same as that of the other part. A surface acoustic wave of two or more frequencies different from a surface acoustic wave of a center frequency that is formed to have a width different from the width of the electrode and propagates in a direction perpendicular to the longitudinal direction of the electrode fingers determined by the spacing of the electrode fingers. A surface acoustic wave device characterized in that the frequency is excited in a direction different from the propagation direction of surface acoustic waves.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1976131746U JPS6143311Y2 (en) | 1976-09-30 | 1976-09-30 | |
| GB21126/77A GB1565756A (en) | 1976-09-30 | 1977-05-19 | Surface elastic wave devices |
| US05/800,544 US4128819A (en) | 1976-09-30 | 1977-05-25 | Surface elastic wave device |
| US05/800,627 US4126800A (en) | 1976-09-30 | 1977-05-25 | Surface elastic wave device using side lobes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1976131746U JPS6143311Y2 (en) | 1976-09-30 | 1976-09-30 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5471934U JPS5471934U (en) | 1979-05-22 |
| JPS6143311Y2 true JPS6143311Y2 (en) | 1986-12-08 |
Family
ID=29098625
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1976131746U Expired JPS6143311Y2 (en) | 1976-09-30 | 1976-09-30 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6143311Y2 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5184545A (en) * | 1975-01-21 | 1976-07-23 | Mitsubishi Electric Corp | DANSEI HYOMENHASOCHI |
-
1976
- 1976-09-30 JP JP1976131746U patent/JPS6143311Y2/ja not_active Expired
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5184545A (en) * | 1975-01-21 | 1976-07-23 | Mitsubishi Electric Corp | DANSEI HYOMENHASOCHI |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5471934U (en) | 1979-05-22 |
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