JPS63285018A - Surface acoustic wave multimode filter - Google Patents
Surface acoustic wave multimode filterInfo
- Publication number
- JPS63285018A JPS63285018A JP11904087A JP11904087A JPS63285018A JP S63285018 A JPS63285018 A JP S63285018A JP 11904087 A JP11904087 A JP 11904087A JP 11904087 A JP11904087 A JP 11904087A JP S63285018 A JPS63285018 A JP S63285018A
- Authority
- JP
- Japan
- Prior art keywords
- surface acoustic
- acoustic wave
- resonators
- 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 54
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- 239000000758 substrate Substances 0.000 claims description 5
- 238000010586 diagram Methods 0.000 description 10
- 239000000470 constituent Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005284 excitation 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】
〔産業上の利用分野〕
本発明は弾性表面波共振子を隣接させ、共振子相互間の
音響的結合を利用した弾性表面波多重モードフィルタに
関し、特に、該多重モードフィルタの広帯域化に関する
。Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a surface acoustic wave multimode filter that uses surface acoustic wave resonators adjacent to each other and utilizes acoustic coupling between the resonators. Regarding widening the band of filters.
従来９弾性表面波共振子間の音響的結合を利用した多重
モードフィルタが提案されている（例えば、 Ｈ，Ｆ、
Ｔｉｅｒｅｔｅｎ ｅｔ ａｌ １９７５Ｐｒｏｃ、
Ｕｌｔｒａｓｏｎｉｃｓ ５７５ｐ、１）１） ２９３
〜２９４）。Multimode filters that utilize acoustic coupling between nine surface acoustic wave resonators have been proposed (for example, H, F,
Tierten et al 1975 Proc.
Ultrasonics 575p, 1) 1) 293
~294).
このタイプのフィルタの比帯域は構成する共振子の幅り
と共振子間の距離Ｇで決まる。The fractional band of this type of filter is determined by the width of the constituent resonators and the distance G between the resonators.
上述した従来の弾性表面波多重モードフィルタでは、フ
ィルタ帯域を広帯域化するには、共振子の幅りと共振子
間の距離Ｇとを可能な限り狭くする必要がある。しかし
、共振子の幅を狭くすることはフィルタとしての電気イ
ンピーダンスが高くなり、使いにくいという欠点がある
。In the conventional surface acoustic wave multimode filter described above, in order to widen the filter band, it is necessary to make the width of the resonators and the distance G between the resonators as narrow as possible. However, narrowing the width of the resonator increases the electrical impedance of the filter, making it difficult to use.
また、最も広帯域になるのは共振子の幅りが０λ（λ：
インターディジタル形電極の周期）であり、実質的に不
可能である。Furthermore, the widest band is obtained when the resonator width is 0λ (λ:
period of interdigital electrodes) and is virtually impossible.
本発明の目的は、各共振子の幅を狭くすることなく、広
帯域化が可能な弾性表面波多重モードフィルタを提供す
ることにある。An object of the present invention is to provide a surface acoustic wave multimode filter that can provide a wide band without narrowing the width of each resonator.
本発明によれば、圧電基板上に、インターディジタル形
電極を有する弾性表面波共振子を。According to the present invention, a surface acoustic wave resonator having interdigitated electrodes is provided on a piezoelectric substrate.
弾性表面波の伝搬方向に直角に相隣接するように配置し
、前記弾性表面波共振子相互間の音響的結合を利用した
多重モードフィルタにおいて。A multimode filter that utilizes acoustic coupling between the surface acoustic wave resonators, which are arranged adjacent to each other at right angles to the propagation direction of surface acoustic waves.
前記弾性表面波共振子の数が６個以上であり。The number of the surface acoustic wave resonators is six or more.
かつ、入力用弾性表面波共振子と出力用弾性表面波共振
子が相交互に配置され、前記入力用及び前記出力用弾性
表面波共振子のうち、入力用か出力用かに注目した機能
が同じ共振子同志が互に電気的に並列接続されているこ
とを特徴とする弾性表面波多重モードフィルタが得られ
る。Further, the surface acoustic wave resonators for input and the surface acoustic wave resonators for output are arranged alternately, and the function focuses on whether the surface acoustic wave resonators for input or output are for input or output. A surface acoustic wave multimode filter characterized in that the same resonators are electrically connected in parallel can be obtained.
以下憩日 〔実施例〕 次に本発明の実施例について図面を参照して説明する。The following rest days 〔Example〕 Next, embodiments of the present invention will be described with reference to the drawings.
第１図を参照すると９本発明の一実施例による弾性表面
波多重モードフィルタは、圧電基板１０上に、形成され
た４個の弾性衣°面波共振子２１．２２．２３及び２４
を有している。弾性表面波共振子２１．２２．２５及び
２４の各々は、入力用又は出力用インターディジタル形
電極１１又は１２と、その両側に位置する一対の反射器
１３及び１４とを有している。４個のインターディジタ
ル形電極１１及び１２の各々は２両手の指（電極指）を
組み合わせたような形状の電極である。電極指の各々は
２図示してないが。Referring to FIG. 1, a surface acoustic wave multimode filter according to an embodiment of the present invention includes four elastic surface wave resonators 21, 22, 23, and 24 formed on a piezoelectric substrate 10.
have. Each of the surface acoustic wave resonators 21, 22, 25 and 24 has an input or output interdigital electrode 11 or 12 and a pair of reflectors 13 and 14 located on both sides thereof. Each of the four interdigital electrodes 11 and 12 is shaped like a combination of fingers (electrode fingers) of two hands. Each of the electrode fingers is shown in two figures (not shown).
第１図のＡ−Ａ’ラインに平行に延びている。本実施例
による弾性表面波多重モードフィルタは。It extends parallel to line AA' in FIG. The surface acoustic wave multimode filter according to this embodiment is as follows.
圧電基板１０上に１弾性表面波共振子２１．２２゜２３
及び２４を９弾性表面波の伝搬方向（第１図のＡ−Ａ’
ラインに垂直な方向）に直角に（即ち、横方向に）相隣
接するように配置し１弾性表面波共振子相互間の音響的
結合を利用する。1 surface acoustic wave resonator 21.22°23 on the piezoelectric substrate 10
and 24 is 9 the propagation direction of the surface acoustic wave (A-A' in Figure 1).
The surface acoustic wave resonators are arranged adjacent to each other at right angles (that is, in the lateral direction) to the line (perpendicular to the line), and acoustic coupling between one surface acoustic wave resonator is utilized.
入力用弾性表面波共振子２１及び２６と出力用弾性表面
波共振子２２及び２４とは相交互に配置されている。入
力用弾性表面波共振子２１及び２６同志は、互に電気的
に並列接続されて入力端子ＩＮに接続される。出力用弾
性表面波共振子２２及び２４同志も、互に電気的に並列
接続されて出力端子ＯＵＴに接続される。即ち。The input surface acoustic wave resonators 21 and 26 and the output surface acoustic wave resonators 22 and 24 are arranged alternately. The input surface acoustic wave resonators 21 and 26 are electrically connected in parallel to each other and connected to the input terminal IN. The output surface acoustic wave resonators 22 and 24 are also electrically connected in parallel to each other and connected to the output terminal OUT. That is.
入力用か出力用かに注目した機能が同じ共振子同志が互
に電気的に接続されている。Resonators having the same function, whether for input or output, are electrically connected to each other.
第１図つ弾性表面波多重モードフィルタは。Figure 1 shows a surface acoustic wave multimode filter.
入力用の弾性表面波共振子に信号が印加されると、入力
用の弾性表面波共振子には、それぞれ同相の弾性表面波
が励振され、伝搬する。このフィルタは導波路として離
散的な固有モードのみ伝搬可能で、それらのモードの中
でも、第２図にこのフィルタの横モード分布を示したよ
うに、上述の励振分布と結合可能なモード５１゜５２の
み伝搬し、入出力用め弾性表面波共振子間で音響結合さ
れ、フィルタとして機能する。When a signal is applied to the input surface acoustic wave resonators, in-phase surface acoustic waves are excited and propagate in the input surface acoustic wave resonators. This filter can propagate only discrete eigenmodes as a waveguide, and among these modes, as shown in the transverse mode distribution of this filter in Fig. 2, there are modes 51, 52, which can be combined with the excitation distribution described above. It is acoustically coupled between the input and output surface acoustic wave resonators, and functions as a filter.
なお、５１はＳｏ対称モード、５２はａ１反対称モード
を示している。Note that 51 indicates the So symmetric mode, and 52 indicates the a1 antisymmetric mode.
本実施例において９例えば、４つの共振子２１．２２．
２３及び２４の横方向の端から端までの距離Ｗが３０人
とすると、導波路としては多数の固有モードが存在し１
例えば第３図のように、対称モードｓｏ ＋ ８１ ＋
反対称モードａＯｒａ１の計４つある。しかし、第１図
に示したように、入力用及び出力用共振子を交互に配置
し。In this embodiment, nine, for example, four resonators 21, 22 .
Assuming that the distance W between the ends of 23 and 24 in the lateral direction is 30 people, there are many eigenmodes as a waveguide, and 1
For example, as shown in Figure 3, the symmetric mode so + 81 +
There are a total of four antisymmetric modes aOra1. However, as shown in FIG. 1, the input and output resonators are arranged alternately.
電気的に並列接続することにより、第２図で示すＳｏモ
ードとａ１モードのみ入出力の結合が可能となる。この
時、フィルタの帯域はＳ。とａ１フィルタの場合、モー
ド結合は、第５図に示すように＋ＳＯ対称モード６１と
ａｎ反対称モード６２であって、第３図において＋ＳＯ
とａＯの周波数上昇率の差はη２である。By electrically connecting in parallel, input and output can be coupled only in the So mode and the a1 mode shown in FIG. 2. At this time, the filter band is S. In the case of the and a1 filter, the mode coupling is a +SO symmetric mode 61 and an antisymmetric mode 62 as shown in FIG.
The difference in frequency increase rate between and aO is η2.
第１図の実施例のη１は１２にくらべ、２〜３倍の値が
可能であり、このことは本発明により。Compared to 12 in the embodiment of FIG. 1, .eta.1 can be 2 to 3 times as large as 12, and this is achieved by the present invention.
この種のフィルタの大幅な広帯域化が可能となり、設計
に自由度を与えることができることを電気的に直列接続
した第６図に示す２重モード２段フィルタがあるが、広
帯域化は不可能であり２本発明とのちがいは明らかであ
る。There is a dual-mode two-stage filter shown in Figure 6, which is electrically connected in series, which makes it possible to significantly widen the band of this kind of filter and give flexibility in design, but it is not possible to widen the band. The difference between this invention and the present invention is obvious.
第７図を参照すると２本発明の他の実施例による弾性表
面波多重モードフィルタは、３個の弾性表面波共振子３
１．３２及び６６で構成され。Referring to FIG. 7, a surface acoustic wave multimode filter according to another embodiment of the present invention includes three surface acoustic wave resonators 3.
1.32 and 66.
出力用インターディジタル形電極１２同志が互に電気的
に並列接続されている。この第７図のフィルタも、第１
図のフィルタと同様に機能し。The output interdigital electrodes 12 are electrically connected in parallel. This filter in Fig. 7 also has the first
Works similarly to the filter in the diagram.
フィルタ帯域の広帯域化が可能となる。It becomes possible to widen the filter band.
以上説明したように２本発明では、各共振子の幅を狭く
することなく、フィルタ帯域の広帯域化が可能な弾性表
面波多重モードフィルタが得られる。As explained above, in the second aspect of the present invention, a surface acoustic wave multi-mode filter can be obtained in which the filter band can be widened without narrowing the width of each resonator.
は１余８is 1 remainder 8
第１図は本発明の一実施例による弾性表面波多重モード
フィルタの構成図、第２図は第１図のフィルタのＡ −
Ａ’面で見たモード分布を示した図、第３図は第１図の
フィルタの機能を説明するために、モード毎の周波数上
昇率の導波路幅Ｗとの関係を示した図、第４図は従来の
弾性表面波多重モードフィルタの構成図、第５図は第４
図の弾性表面波多重モードフィルタのＢ−Ｂ′面で見た
モード分布を示した図、第６図は従来の別の弾性表面波
多重モードフィルタの構成図、第７図は本発明の他の実
施例による弾性表面波多重モードフィルタの構成図であ
る。
１０・・・圧電基板、１１・・・入力用インターディジ
タル形電極、１２・・・出力用インターディジタル形電
極、１３及び１４・・・反射器、２１，２２゜２３．２
４，３１．３２及び６６・・・弾性表面波共振子。
第６図
第７図FIG. 1 is a block diagram of a surface acoustic wave multimode filter according to an embodiment of the present invention, and FIG. 2 is a diagram of the filter A-
Figure 3 is a diagram showing the mode distribution seen in the A' plane, and Figure 3 is a diagram showing the relationship between the frequency increase rate of each mode and the waveguide width W in order to explain the function of the filter in Figure 1. Figure 4 is a configuration diagram of a conventional surface acoustic wave multimode filter, and Figure 5 is a diagram of a conventional surface acoustic wave multimode filter.
FIG. 6 is a diagram showing the mode distribution of the surface acoustic wave multimode filter as seen in the plane B-B', FIG. 6 is a configuration diagram of another conventional surface acoustic wave multimode filter, and FIG. FIG. 2 is a configuration diagram of a surface acoustic wave multimode filter according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Piezoelectric substrate, 11... Interdigital electrode for input, 12... Interdigital electrode for output, 13 and 14... Reflector, 21, 22° 23.2
4, 31, 32 and 66... surface acoustic wave resonators. Figure 6 Figure 7
Claims (1)
弾性表面波共振子を、弾性表面波の伝搬方向に直角に相
隣接するように配置し、前記弾性表面波共振子相互間の
音響的結合を利用した弾性表面波多重モードフィルタに
おいて、前記弾性表面波共振子の数が３個以上であり、
かつ、入力用弾性表面波共振子と出力用弾性表面波共振
子が相交互に配置され、前記入力用及び前記出力用弾性
表面波共振子のうち、入力用か出力用かに注目した機能
が同じ共振子同志が互に電気的に並列接続されているこ
とを特徴とする弾性表面波多重モードフィルタ。1. Surface acoustic wave resonators having interdigital electrodes are arranged adjacent to each other at right angles to the propagation direction of the surface acoustic waves on a piezoelectric substrate, and acoustic coupling between the surface acoustic wave resonators is achieved. In the surface acoustic wave multimode filter used, the number of surface acoustic wave resonators is three or more,
Further, the surface acoustic wave resonators for input and the surface acoustic wave resonators for output are arranged alternately, and the function focuses on whether the surface acoustic wave resonators for input or output are for input or output. A surface acoustic wave multimode filter characterized in that resonators of the same type are electrically connected in parallel to each other.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11904087A JPH0654858B2 (en) | 1987-05-18 | 1987-05-18 | Surface acoustic wave multiple mode filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11904087A JPH0654858B2 (en) | 1987-05-18 | 1987-05-18 | Surface acoustic wave multiple mode filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63285018A true JPS63285018A (en) | 1988-11-22 |
| JPH0654858B2 JPH0654858B2 (en) | 1994-07-20 |
Family
ID=14751457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11904087A Expired - Lifetime JPH0654858B2 (en) | 1987-05-18 | 1987-05-18 | Surface acoustic wave multiple mode filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0654858B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02182012A (en) * | 1989-01-06 | 1990-07-16 | Murata Mfg Co Ltd | Surface acoustic wave device |
| JPH03119816A (en) * | 1989-10-03 | 1991-05-22 | Kokusai Electric Co Ltd | Two-terminal pair surface acoustic wave resonator and surface acoustic wave filter |
| JPH06216694A (en) * | 1992-11-25 | 1994-08-05 | Rf Monolithics Inc | Surface acoustic wave device for generating only symmetric vibration mode elastic wave itself or generating output signal having only it |
| US5581141A (en) * | 1993-10-08 | 1996-12-03 | Matsushita Electric Industrial Co., Ltd. | Surface acoustic wave filter |
| US6043726A (en) * | 1995-09-26 | 2000-03-28 | Thomson-Csf | Surface acoustic wave filter utilizing the coupling of three acoustic pathways |
| US6140890A (en) * | 1997-11-12 | 2000-10-31 | Nec Corporation | Saw filter with multiple reflector pairs |
| US6348845B2 (en) * | 1996-05-23 | 2002-02-19 | Matsushita Electric Industrial Co., Ltd. | Surface acoustic wave filter and multistage surface acoustic wave filter |
| 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 |
-
1987
- 1987-05-18 JP JP11904087A patent/JPH0654858B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02182012A (en) * | 1989-01-06 | 1990-07-16 | Murata Mfg Co Ltd | Surface acoustic wave device |
| JPH03119816A (en) * | 1989-10-03 | 1991-05-22 | Kokusai Electric Co Ltd | Two-terminal pair surface acoustic wave resonator and surface acoustic wave filter |
| JPH06216694A (en) * | 1992-11-25 | 1994-08-05 | Rf Monolithics Inc | Surface acoustic wave device for generating only symmetric vibration mode elastic wave itself or generating output signal having only it |
| US5581141A (en) * | 1993-10-08 | 1996-12-03 | Matsushita Electric Industrial Co., Ltd. | Surface acoustic wave filter |
| US5932950A (en) * | 1993-10-08 | 1999-08-03 | Matsushita Electric Industrial Co., Ltd. | Surface acoustic wave filter |
| US6043726A (en) * | 1995-09-26 | 2000-03-28 | Thomson-Csf | Surface acoustic wave filter utilizing the coupling of three acoustic pathways |
| US6348845B2 (en) * | 1996-05-23 | 2002-02-19 | Matsushita Electric Industrial Co., Ltd. | Surface acoustic wave filter and multistage surface acoustic wave filter |
| 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 |
| US6140890A (en) * | 1997-11-12 | 2000-10-31 | Nec Corporation | Saw filter with multiple reflector pairs |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0654858B2 (en) | 1994-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6329888B1 (en) | Reflection inversion surface acoustic wave transducer and filter | |
| KR100290204B1 (en) | Multimode surface acoustic wave filter | |
| JP2957159B2 (en) | Differential input / output surface acoustic wave device with proximity coupling | |
| JPH06260876A (en) | Surface acoustic wave filter | |
| KR970008851A (en) | Surface acoustic wave device | |
| JPS6294009A (en) | Staggered surface acoustic resonator for differential detection | |
| JP3651291B2 (en) | Surface acoustic wave device | |
| JPH0758585A (en) | Surface acoustic wave filter | |
| JPH10145173A (en) | Interdigital transducer and surface acoustic wave multimode filter | |
| JPH0654858B2 (en) | Surface acoustic wave multiple mode filter | |
| JP3918497B2 (en) | Edge reflection type surface acoustic wave device | |
| JP4432968B2 (en) | Resonator type SAW filter | |
| US6037700A (en) | Surface acoustic wave device | |
| JPS61192112A (en) | Surface acoustic wave device | |
| JPS6247206A (en) | Surface acoustic wave multimode filter | |
| JP3154402B2 (en) | SAW filter | |
| JPH09214284A (en) | Surface acoustic wave device | |
| JP3393945B2 (en) | Vertically coupled dual mode SAW filter | |
| JPH10284988A (en) | Surface acoustic wave filter | |
| JPH04373304A (en) | Surface acoustic wave filter | |
| JP3203796B2 (en) | Multi-mode surface acoustic wave filter | |
| JP3117021B2 (en) | Surface acoustic wave filter | |
| JP3132109B2 (en) | 2-port SAW resonator | |
| JP3480785B2 (en) | Longitudinal mode resonator surface acoustic wave filter | |
| JPH04113711A (en) | Longitudinal dual mode surface acoustic wave filter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |