JPH0244168B2 - DANSEIHYOMENHASOCHI - Google Patents
DANSEIHYOMENHASOCHIInfo
- Publication number
- JPH0244168B2 JPH0244168B2 JP14566382A JP14566382A JPH0244168B2 JP H0244168 B2 JPH0244168 B2 JP H0244168B2 JP 14566382 A JP14566382 A JP 14566382A JP 14566382 A JP14566382 A JP 14566382A JP H0244168 B2 JPH0244168 B2 JP H0244168B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- surface acoustic
- acoustic wave
- transducers
- ground 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.)
- Expired - Lifetime
Links
- 238000010897 surface acoustic wave method Methods 0.000 claims description 21
- 230000005284 excitation Effects 0.000 description 10
- 230000005684 electric field Effects 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02818—Means for compensation or elimination of undesirable effects
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Surface Acoustic Wave Elements And Circuit Networks Thereof (AREA)
Description
【発明の詳細な説明】
本発明は対向する弾性表面波変換器の間に接地
電極を有する弾性表面波装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface acoustic wave device having a ground electrode between opposing surface acoustic wave transducers.
従来から弾性表面波変換器間の電磁的静電的結
合を抑圧するために第１図に示すように、変換器
１および２間に接地電極３を配置した構造の弾性
表面波装置が知られている。このような表面波装
置において装置の小型化および遅延歪特性、振幅
特性の改善を行う場合、変換器１，２間の間隔を
できる限り短くする必要がある。しかし、変換器
間の間隔を短くすることによつて隣接接地電極３
と変換器１の電極指４間に電界発生し、これによ
り不要弾性表面波が発生する。この結果、この不
要弾性表面波と所望の弾性表面波が受信側変換器
２で結合し、両弾性表面波の伝搬距離の差（ln−
ls）によつて通過帯域内および帯域外に周期△
＝ｖ／（ln−ls）の大きなリブルが発生し、周波
数特性の劣化をもたらしている。 Conventionally, there has been known a surface acoustic wave device having a structure in which a ground electrode 3 is disposed between transducers 1 and 2, as shown in FIG. 1, in order to suppress electromagnetic and electrostatic coupling between surface acoustic wave transducers. ing. In order to miniaturize such a surface acoustic wave device and improve delay distortion characteristics and amplitude characteristics, it is necessary to shorten the distance between the transducers 1 and 2 as much as possible. However, by shortening the spacing between transducers, adjacent ground electrodes 3
An electric field is generated between the electrode finger 4 of the transducer 1 and an unnecessary surface acoustic wave. As a result, this unnecessary surface acoustic wave and the desired surface acoustic wave are combined at the receiving side transducer 2, and the difference in the propagation distance of both surface acoustic waves (l n −
period △ within the passband and outside the band by l s )
A large ribble of =v/(l n -l s ) occurs, resulting in deterioration of frequency characteristics.
本発明の目的は、弾性表面波変換器の間に配置
されたシールド電極と変換器の電極指との間で発
生する不要弾性表面波を抑圧し、小型で良好な周
波数特性を有する弾性表面波装置を提供すること
にある。 An object of the present invention is to suppress unnecessary surface acoustic waves generated between a shield electrode placed between a surface acoustic wave transducer and an electrode finger of the transducer, and to produce a surface acoustic wave that is small and has good frequency characteristics. The goal is to provide equipment.
次に図面を参照して本発明を詳細に説明する。 Next, the present invention will be explained in detail with reference to the drawings.
第２図は本発明の第１の実施例を示す平面図で
ある。図において、本発明の表面波装置は、励振
側変換器５と、受信側変換器６と、これらの間に
配置された接地電極７と、励振側変換器５と接地
電極７との間に配置され変換器５と同一周期を有
し電気的に開放された２本の電極８とから構成さ
れている。 FIG. 2 is a plan view showing the first embodiment of the present invention. In the figure, the surface acoustic wave device of the present invention includes an excitation side transducer 5, a reception side transducer 6, a ground electrode 7 disposed between these, and a ground electrode 7 between the excitation side transducer 5 and the ground electrode 7. It consists of two electrically open electrodes 8 which are arranged and have the same period as the transducer 5.
ここで不要波が抑圧される理由について詳細に
説明する。第２図の励振電極５の外側の電極指は
信号側と接地側とに分割されており開倣電極８に
は信号側に対向する部分と接地側に対向する部分
に正電荷と負電荷が発生する。しかしこの開倣電
極は一体であるため、誘起された電荷は相殺され
る。従つてシールド電極７と励振電極５との間に
電界はかからずこれら電極５と７との間では不要
波は励振されず、結果的に不要波が抑圧される。 Here, the reason why unnecessary waves are suppressed will be explained in detail. The outer electrode fingers of the excitation electrode 5 in FIG. 2 are divided into a signal side and a ground side, and the open scanning electrode 8 has positive charges and negative charges in the part facing the signal side and the part facing the ground side. Occur. However, since this aperture electrode is integral, the induced charges are canceled out. Therefore, no electric field is applied between the shield electrode 7 and the excitation electrode 5, and no unnecessary waves are excited between these electrodes 5 and 7, and as a result, unnecessary waves are suppressed.
第３図は、受信側変換器９および１０と、励振
側変換器１１と、これらの間に配置された接地電
極１２および１３と、変換器９および１０と接地
電極１２および１３との間に配置された２本の電
気的に開放された電極１４とから構成される本発
明の第２の実施例を示す。 FIG. 3 shows receiving transducers 9 and 10, excitation transducer 11, grounding electrodes 12 and 13 disposed between them, and transducers 9 and 10 and grounding electrodes 12 and 13. 2 shows a second embodiment of the invention, consisting of two electrically open electrodes 14 arranged;
第４図は、重み付けされた励振側変換器１５
と、受信側変換器１６と、マルチストリツプカプ
ラ（Ｍ・Ｓ・Ｃ）１７と、各変換器１５および１
６とMSC１７との間に設けられた接地電極１８
および１９と、各変換器と接地電極の間に設けら
れた電気的に開放された２本の電極２０とから構
成されている。 FIG. 4 shows the weighted excitation side converter 15
, a receiving side converter 16, a multi-strip coupler (M.S.C.) 17, and each converter 15 and 1.
6 and the ground electrode 18 provided between the MSC 17
and 19, and two electrically open electrodes 20 provided between each converter and the ground electrode.
第５図は第１図に示す従来の弾性表面波装置の
周波数特性で、帯域内リプル4dB、帯域外減衰量
20dBである。 Figure 5 shows the frequency characteristics of the conventional surface acoustic wave device shown in Figure 1, with in-band ripple of 4 dB and out-of-band attenuation.
It is 20dB.
第６図は本発明による弾性表面波装置の周波数
特性で帯域内リプル2dB以下、帯域外減衰量
29dB以上に改善されている。 Figure 6 shows the frequency characteristics of the surface acoustic wave device according to the present invention, with in-band ripple of 2 dB or less and out-of-band attenuation.
This has been improved to over 29dB.
以上のように本発明により周波数特性を改善し
た良好な特性を有する弾性表面波装置が得られ
る。 As described above, according to the present invention, a surface acoustic wave device having improved frequency characteristics and good characteristics can be obtained.
第１図は従来の弾性表面波装置を示す平面図、
第２図〜４図は本発明の実施例を示す平面図、第
５図および第６図は従来の弾性表面波装置および
本発明による弾性表面波装置の周波数特性を示す
図である。
図において、１…励振電極、２…受信電極、３
…接地電極、４…正電極、５…励振電極、６…受
信電極、７…接地電極、８…開倣電極、９，１０
…受信電極、１１…励振電極、１２，１３…接地
電極、１４…接地電極、１５…励振電極、１６…
受信電極、１７…マルチストリツプカプラ、１
８，１９…接地電極、２０…開倣電極。
FIG. 1 is a plan view showing a conventional surface acoustic wave device.
2 to 4 are plan views showing embodiments of the present invention, and FIGS. 5 and 6 are diagrams showing frequency characteristics of a conventional surface acoustic wave device and a surface acoustic wave device according to the present invention. In the figure, 1...excitation electrode, 2...reception electrode, 3
...Ground electrode, 4...Positive electrode, 5...Excitation electrode, 6...Reception electrode, 7...Ground electrode, 8...Open copying electrode, 9,10
...Receiving electrode, 11... Excitation electrode, 12, 13... Ground electrode, 14... Ground electrode, 15... Excitation electrode, 16...
Receiving electrode, 17...Multi-strip coupler, 1
8, 19...ground electrode, 20...open copying electrode.
Claims (1)
変換器と、前記変換器の間に接地電極を有し、前
記変換器と前記接地電極の間に電気的に開放され
た少なくとも２本の電極指を設けたことを特徴と
する弾性表面波装置。1 At least two surface acoustic wave transducers facing each other, a ground electrode between the transducers, and at least two electrically open electrode fingers between the transducers and the ground electrode. A surface acoustic wave device characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14566382A JPH0244168B2 (en) | 1982-08-23 | 1982-08-23 | DANSEIHYOMENHASOCHI |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14566382A JPH0244168B2 (en) | 1982-08-23 | 1982-08-23 | DANSEIHYOMENHASOCHI |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5934712A JPS5934712A (en) | 1984-02-25 |
| JPH0244168B2 true JPH0244168B2 (en) | 1990-10-03 |
Family
ID=15390210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14566382A Expired - Lifetime JPH0244168B2 (en) | 1982-08-23 | 1982-08-23 | DANSEIHYOMENHASOCHI |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0244168B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7271685B2 (en) | 2004-07-15 | 2007-09-18 | Murata Manufacturing Co., Ltd. | Surface acoustic wave filter |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6450610A (en) * | 1987-08-20 | 1989-02-27 | Showa Electric Wire & Cable Co | Surface acoustic wave device |
| JP3487772B2 (en) * | 1998-03-11 | 2004-01-19 | 富士通株式会社 | Surface acoustic wave filter |
-
1982
- 1982-08-23 JP JP14566382A patent/JPH0244168B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7271685B2 (en) | 2004-07-15 | 2007-09-18 | Murata Manufacturing Co., Ltd. | Surface acoustic wave filter |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5934712A (en) | 1984-02-25 |
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