JP3033336B2 - Surface acoustic wave filter - Google Patents
Surface acoustic wave filterInfo
- Publication number
- JP3033336B2 JP3033336B2 JP4069637A JP6963792A JP3033336B2 JP 3033336 B2 JP3033336 B2 JP 3033336B2 JP 4069637 A JP4069637 A JP 4069637A JP 6963792 A JP6963792 A JP 6963792A JP 3033336 B2 JP3033336 B2 JP 3033336B2
- Authority
- JP
- Japan
- Prior art keywords
- acoustic wave
- surface acoustic
- electrode
- apodized
- wave filter
- 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 - Fee Related
Links
Landscapes
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、弾性表面波フィルタに
関し、特に、入出力用アポダイズド電極間にマルチスト
リップカプラーを配設してなる弾性表面波フィルタに関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface acoustic wave filter, and more particularly, to a surface acoustic wave filter having a multistrip coupler between input and output apodized electrodes.
【０００２】[0002]
【従来の技術】従来、この種の弾性表面波フィルタとし
て、図２に示すものが知られている。2. Description of the Related Art Conventionally, a surface acoustic wave filter of this type is known as shown in FIG.
【０００３】同図において、圧電電極２１上には、二つ
のアポダイズド電極２２，２３と、両電極２２，２３に
マルチストリップカプラー２４とが配設されている。ア
ポダイズド電極２２，２３においては、重み付け量を表
すサイドローブ２６，２７がその中心位置を横一列状に
併設され、また、ボンディングパッド２５については接
地されていない。In FIG. 1, two apodized electrodes 22 and 23 are provided on a piezoelectric electrode 21, and a multistrip coupler 24 is provided on both electrodes 22 and 23. In the apodized electrodes 22 and 23, side lobes 26 and 27 indicating the weighting amounts are arranged side by side at the center thereof, and the bonding pad 25 is not grounded.
【０００４】かかる構成において、入力側のアポダイズ
ド電極２２（２３）から励振されて表面波をストリップ
アレイ２４に入射せしめると、圧電結合を介してストリ
ップアレイの残部に表面波が表れて出力側のアポダイズ
ド電極２３（２２）に受信される。In such a configuration, when the surface wave is excited from the apodized electrode 22 (23) on the input side and is incident on the strip array 24, the surface wave appears on the remaining portion of the strip array via the piezoelectric coupling and the apodized electrode on the output side. The signal is received by the electrodes 23 (22).
【０００５】[0005]
【発明が解決しようとする課題】上述した従来の弾性表
面波フィルタにおいては、マルチストリップカプラを構
成する金属ストリップアレイと入出力信号用アポダイズ
ド電極の信号用の接地していない側の電極指が隣り合っ
ているため、金属ストリップアレイと電極指の間に不要
な電界が生じ、さらに、入出力信号用のアポダイズド電
極間で電磁結合しやすいという課題があった。In the above-described conventional surface acoustic wave filter, a metal strip array constituting a multistrip coupler and an electrode finger of the apodized electrode for input / output signals which are not grounded are adjacent to each other. Because of the matching, an unnecessary electric field is generated between the metal strip array and the electrode fingers, and further, there is a problem that electromagnetic coupling is easily performed between the apodized electrodes for input / output signals.
【０００６】本発明は、上記課題にかんがみてなされた
もので、不要な電界の発生や電磁結合を防いで、フィル
タ特性を向上せしめた弾性表面波フィルタの提供を目的
とする。The present invention has been made in view of the above problems, and has as its object to provide a surface acoustic wave filter having improved filter characteristics by preventing generation of an unnecessary electric field and electromagnetic coupling.
【０００７】[0007]
【課題を解決するための手段】上記目的を達成するた
め、請求項１にかかる発明は、圧電基板上にて入出力用
アポダイズド電極間にマルチストリップカプラーを配設
して構成される弾性表面波フィルタにおいて、上記入出
力用アポダイズド電極のバスパーのチップ中央側が接地
するとともに、上記入出力用アポダイズド電極の各電極
指の交差幅の中心位置が、表面波の伝搬方向に対して電
極の中央部から左右に離れるにしたがい徐々にバスパー
方向に傾斜し、かつ、その傾斜方向が表面波の伝搬方向
の垂直方向に対してチップ中心から外側方向となるよう
にした構成としてある。According to a first aspect of the present invention, there is provided a surface acoustic wave having a multistrip coupler disposed between input / output apodized electrodes on a piezoelectric substrate. in the filter, the input and
The center of the bus aper tip of the force apodized electrode is grounded
And each electrode of the above-mentioned apodized electrode for input / output
The center position of the finger's intersection width is
As you move left and right from the center of the pole,
Direction, and the direction of the inclination is the propagation direction of the surface wave.
To the outside from the chip center to the vertical direction
There is a configuration.
【０００８】[0008]
【作用】上記のように構成した請求項１にかかる発明に
おいては、サイドローブの傾斜によって電極指と金属ス
トリップアレイとの間に不要な電界が生じない。また、
信号用電極指が接地側電極指に囲まれているので入出力
信号用アポダイズド電極間の電磁結合が弱められる。According to the first aspect of the present invention, an unnecessary electric field is not generated between the electrode finger and the metal strip array due to the inclination of the side lobe. Also,
Since the signal electrode fingers are surrounded by the ground electrode fingers, electromagnetic coupling between the input and output signal apodized electrodes is weakened.
【０００９】[0009]
【実施例】以下、図面にもとづいて本発明の実施例を説
明する。図１は、本発明の一実施例にかかる弾性表面波
フィルタのブロック図である。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a surface acoustic wave filter according to one embodiment of the present invention.
【００１０】 同図において、１１は圧電基板、１２，１
３は入出力用アポダイズド電極、１４はマルチストリッ
プカプラーである。入出力用アポダイズド電極１２，１
３は、重み付け量を表すサイドローブ１６，１７が同方
向に傾斜しており、傾斜方向はチップの中心から外側方
向となっている。 In FIG . 1, reference numeral 11 denotes a piezoelectric substrate;
Reference numeral 3 denotes an apodized electrode for input and output, and 14 denotes a multistrip coupler. Apodized electrode for input / output 12, 1
In 3, the side lobes 16 and 17 representing the weighting amounts are inclined in the same direction, and the inclination direction is outward from the center of the chip.
【００１１】 すなわち、電極指の交差幅の中心位置が、
表面波の伝搬方向に対して電極の中央部から左右に離れ
るに従って、徐々に同じバスバー方向に傾斜しており、
かつ、傾斜方向は、表面波の伝搬方向の垂直方向に対し
てチップ中心から外側方向となっている。 [0011] That is, the center position of the cross width of the electrode fingers,
As it moves away from the center of the electrode to the left and right with respect to the propagation direction of the surface wave, it is gradually inclined in the same busbar direction,
The tilt direction is outward from the center of the chip with respect to the direction perpendicular to the propagation direction of the surface wave.
【００１２】 また、ボンディングパッド１５はともに接
地されている。すなわち、アポダイズド電極におけるバ
スバーのチップ中央側を接地している。 The bonding pads 15 are both grounded. That is, the center of the chip of the bus bar in the apodized electrode is grounded.
【００１３】 次に、上記構成からなる本実施例の動作を
説明する。本実施例のように入出力用アポダイズド電極
１２，１３の接地が中央側バスバーであり、交差部が外
側に傾斜していると、互いに近接している電極指が、接
地されている中心側バスバーに接続されている長い電極
指となるので、これがシールドとなって電磁結合を生じ
にくくさせる。 [0013] Next, the operation of this embodiment having the above structure. As in the present embodiment, the grounding of the input / output apodized electrodes 12 and 13 is the center busbar, and if the intersection is inclined outward, the electrode fingers close to each other will be connected to the grounded busbar. , Which serve as a shield, making it difficult for electromagnetic coupling to occur.
【００１４】[0014]
【発明の効果】以上説明したように本発明は、不要な電
界の発生や電磁結合を防ぐことにより、低帯域内リップ
ル及び帯域外減衰量を有する弾性表面波フィルタを提供
することができる。As described above, the present invention can provide a surface acoustic wave filter having low in-band ripple and out-of-band attenuation by preventing generation of unnecessary electric fields and electromagnetic coupling.
【図１】本発明の一実施例にかかる弾性表面波フィルタ
の上面図である。FIG. 1 is a top view of a surface acoustic wave filter according to one embodiment of the present invention.
【図２】従来の弾性表面波フィルタの上面図である。FIG. 2 is a top view of a conventional surface acoustic wave filter.
１２，１３…入出力用アポダイズド電極 １５…バスバー １６，１７…サイドローブ 12, 13 ... Apodized electrode for input / output 15 ... Bus bar 16, 17 ... Side lobe
フロントページの続き (56)参考文献 特開 昭62−219807（ＪＰ，Ａ) 特開 昭61−107805（ＪＰ，Ａ) 特開 昭63−266913（ＪＰ，Ａ) 特開 昭58−190117（ＪＰ，Ａ) 特開 平１−220909（ＪＰ，Ａ) 特開 昭58−43609（ＪＰ，Ａ) 特開 昭59−36414（ＪＰ，Ａ) 特開 昭60−1913（ＪＰ，Ａ) 特開 昭58−43609（ＪＰ，Ａ) 特開 昭57−60722（ＪＰ，Ａ) 特開 昭57−204621（ＪＰ，Ａ) 実開 昭62−8722（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) H03H 9/145 H03H 9/25 H03H 9/64 Continuation of front page (56) References JP-A-62-219807 (JP, A) JP-A-61-107805 (JP, A) JP-A-63-266913 (JP, A) JP-A-58-190117 (JP) JP-A-1-220909 (JP, A) JP-A-58-43609 (JP, A) JP-A-59-36414 (JP, A) JP-A-60-1913 (JP, A) 58-43609 (JP, A) JP-A-57-60722 (JP, A) JP-A-57-204621 (JP, A) JP-A-62-8722 (JP, U) (58) Fields investigated (Int. Cl. 7 , DB name) H03H 9/145 H03H 9/25 H03H 9/64
Claims (1)
極間にマルチストリップカプラーを配設して構成される
弾性表面波フィルタにおいて、上記入出力用アポダイズド電極のバスパーのチップ中央
側が接地するとともに、上記入出力用アポダイズド電極
の各電極指の交差幅の中心位置が、表面波の伝搬方向に
対して電極の中央部から左右に離れるにしたがい徐々に
バスパー方向に傾斜し、かつ、その傾斜方向が表面波の
伝搬方向の垂直方向に対してチップ中心から外側方向と
なるようにした ことを特徴とする弾性表面波フィルタ。1. A surface acoustic wave filter comprising a multistrip coupler disposed between input and output apodized electrodes on a piezoelectric substrate , wherein a center of a chip of a busper of the input and output apodized electrodes is provided.
Side is grounded and the above-mentioned apodized electrode for input / output
The center position of the intersection width of each electrode finger is
In contrast, gradually move away from the center of the electrode
Tilt in the direction of the bus par, and the tilt direction is
With respect to the direction perpendicular to the propagation direction
A surface acoustic wave filter characterized in that:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4069637A JP3033336B2 (en) | 1992-02-19 | 1992-02-19 | Surface acoustic wave filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4069637A JP3033336B2 (en) | 1992-02-19 | 1992-02-19 | Surface acoustic wave filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05235686A JPH05235686A (en) | 1993-09-10 |
| JP3033336B2 true JP3033336B2 (en) | 2000-04-17 |
Family
ID=13408583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4069637A Expired - Fee Related JP3033336B2 (en) | 1992-02-19 | 1992-02-19 | Surface acoustic wave filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3033336B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3487772B2 (en) * | 1998-03-11 | 2004-01-19 | 富士通株式会社 | Surface acoustic wave filter |
-
1992
- 1992-02-19 JP JP4069637A patent/JP3033336B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05235686A (en) | 1993-09-10 |
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