JPH04132409A - Surface acoustic wave resonator - Google Patents
Surface acoustic wave resonatorInfo
- Publication number
- JPH04132409A JPH04132409A JP25197590A JP25197590A JPH04132409A JP H04132409 A JPH04132409 A JP H04132409A JP 25197590 A JP25197590 A JP 25197590A JP 25197590 A JP25197590 A JP 25197590A JP H04132409 A JPH04132409 A JP H04132409A
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- surface acoustic
- acoustic wave
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- resonator
- attenuation
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- 238000010897 surface acoustic wave method Methods 0.000 title claims abstract description 60
- 239000011295 pitch Substances 0.000 claims abstract description 26
- 239000002131 composite material Substances 0.000 claims abstract description 13
- 239000000758 substrate Substances 0.000 claims description 2
- 230000015556 catabolic process Effects 0.000 abstract 2
- 238000006731 degradation reaction Methods 0.000 abstract 2
- 238000010586 diagram Methods 0.000 description 14
- 230000000694 effects Effects 0.000 description 8
- 230000007423 decrease Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 238000004891 communication Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000006096 absorbing agent Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
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- 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器で構成する帯域通過フィルタ
、あるいは帯域阻止フィルタに係り、特に阻止帯域での
高減衰特性の実現に好適な共振器構造に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a bandpass filter or a bandstop filter composed of surface acoustic wave resonators, and particularly relates to a resonance filter suitable for realizing high attenuation characteristics in the stopband. Regarding vessel structure.
従来の弾性表面波共振器は、特願昭６０−６０６４５に
記載のように、多数対の交差指電極からなる弾性表面波
トランスデユーサが、共振器内全体で同一の電極ピッチ
となっていた。このときの共振特性は、単一ピークの反
共振点を有していた。また、上記構造で、かつ共振周波
数（電極ピッチ）の異なる複数個の弾性表面波共振器を
直列に接続し、共振器部の電極とアース間の容量を利用
して帯域通過フィルタ、あるいは帯域阻止フィルタを構
成していた。本弾性表面波共振器では、フィルタとして
の通過帯域を共振周波数近傍に、また阻止帯域を***振
周波数近傍に設定して、所望の特性を実現していた。In a conventional surface acoustic wave resonator, as described in Japanese Patent Application No. 60-60645, a surface acoustic wave transducer consisting of multiple pairs of interdigital electrodes had the same electrode pitch throughout the resonator. . The resonance characteristics at this time had a single peak anti-resonance point. In addition, multiple surface acoustic wave resonators with the above structure and different resonant frequencies (electrode pitches) are connected in series, and the capacitance between the electrodes of the resonator section and the ground is used to create a bandpass filter or a bandstop filter. It was configuring a filter. In this surface acoustic wave resonator, the pass band as a filter is set near the resonant frequency, and the stop band is set near the anti-resonant frequency to achieve desired characteristics.
上記従来技術は、各弾性表面波共振器の***振点におけ
る減衰特性の改善の点について配慮がされておらず、隣
り合う***振点間の減衰量が低下し、阻止帯域の高減衰
特性が実現されない問題があった。The above conventional technology does not take into consideration the improvement of the attenuation characteristics at the anti-resonance points of each surface acoustic wave resonator, and the amount of attenuation between adjacent anti-resonance points decreases, resulting in the high attenuation characteristics in the stop band. There was a problem that could not be realized.
第２図に従来技術による１開口弾性表面波共振器を示す
。１は入力端子、２は出力端子、３は入力側共通電極、
４は出力側共通電極、７は圧電基板である。各共通電極
には交互に間挿された電極指が接続されており、多数対
トランスデユーサによる１開口共振器を構成している。FIG. 2 shows a conventional one-aperture surface acoustic wave resonator. 1 is an input terminal, 2 is an output terminal, 3 is an input side common electrode,
4 is an output side common electrode, and 7 is a piezoelectric substrate. Alternately interposed electrode fingers are connected to each common electrode, forming a single-aperture resonator with multiple pairs of transducers.
このとき、各電極指の配列ピッチ（図中Ｐ）は、共振器
内で同一に設定されている。At this time, the arrangement pitch (P in the figure) of each electrode finger is set to be the same within the resonator.
この共振器の等価回路を第３図（ａ）に示す。An equivalent circuit of this resonator is shown in FIG. 3(a).
１０は電極間の静電容量Ｃ０１１１，１２は共振による
インダクタンスＬ１と容量Ｃ１である。このような共振
器のインピーダンス特性は、同図（ｂ）に示すように、
共振周波数ｆ、でインピーダンスがほぼ零、***振周波
数ｆ＆でほぼ無限大となる。10 is the electrostatic capacitance C0111 between the electrodes, and 12 is the inductance L1 and capacitance C1 due to resonance. The impedance characteristics of such a resonator are as shown in FIG.
The impedance becomes almost zero at the resonant frequency f, and becomes almost infinite at the anti-resonant frequency f&.
第４図は１開口弾性表面波共振器を複数個用いる弾性表
面波共振器複合形フィルタの従来構成例である。本例で
は説明の単純化のため、３個の１開口共振器を直列接続
した構成となっている。FIG. 4 shows a conventional configuration example of a surface acoustic wave resonator composite filter using a plurality of one-aperture surface acoustic wave resonators. In order to simplify the explanation, this example has a configuration in which three single-aperture resonators are connected in series.
１５〜１８は外部回路との整合用インダクタ。15 to 18 are inductors for matching with an external circuit.
１３−１〜３は共振周波数の異なる１開口共振器。13-1 to 13-3 are single-aperture resonators with different resonance frequencies.
１４−１〜４は共振器間を接続する共通電極である。Common electrodes 14-1 to 14-4 connect the resonators.
この構成のフィルタの特性は同図（ｂ）に示すように、
***振周波数が異なる３つの１開口共振器の特性１９，
２０，２１の総合特性２２となる。The characteristics of the filter with this configuration are as shown in the same figure (b).
Characteristics of three single-aperture resonators with different anti-resonant frequencies 19,
Comprehensive characteristic 22 of 20 and 21 is obtained.
総合特性２２の減衰極２３，２４．２５は、３つの１開
口共振器の***振周波数ｆ１． ｆ２． ｆ３ に対応
している。The attenuation poles 23, 24, 25 of the overall characteristic 22 correspond to the anti-resonance frequencies f1. of the three one-aperture resonators. f2. Compatible with f3.
本従来例では、上記第 図（ｂ）のように、各減衰極間
の中央部２６．２７において、減衰量が小さくなること
が問題であった。従来は、中央部における減衰特性の劣
化を防ぐために、１開口共振器間の***振周波数の差を
小さくシ、減衰極を接近させる方法を用いていた。しか
し、本方法では、フィルタに要求される帯域幅を確保す
るために、より多数の１開口共振器を必要とするにのた
め、フィルタ全体の損失増となること、およびチップサ
イズが大となり素子歩留りが低下することが欠点となっ
ていた。In this conventional example, the problem is that the amount of attenuation becomes small at the central portions 26 and 27 between the attenuation poles, as shown in FIG. 2B. Conventionally, in order to prevent deterioration of the attenuation characteristics in the central portion, a method has been used in which the difference in anti-resonance frequencies between single-aperture resonators is made small and the attenuation poles are brought closer together. However, this method requires a larger number of single-aperture resonators in order to secure the bandwidth required for the filter, which increases the loss of the entire filter and increases the chip size. The disadvantage was that the yield decreased.
本発明の目的は、１開口弾性表面波共振器に新たな電極
構成の多数対トランスデユーサを採用し、減衰極間の特
性劣化が少ないＳＡＷフィルタを提供することにある。An object of the present invention is to provide a SAW filter in which a multi-pair transducer with a new electrode configuration is employed in a single-aperture surface acoustic wave resonator, and the characteristics between attenuation poles are less deteriorated.
上記目的を達成するために、本発明においては、１開口
弾性表面波共振器の多数対トランスデユーサを、少なく
とも２つ以上の電極ピッチが異なる領域の組み合せで構
成したものである。これにより、複数の減衰極を有する
１開口弾性表面波共振器が実現される。In order to achieve the above object, in the present invention, a multi-pair transducer of a one-aperture surface acoustic wave resonator is configured by a combination of at least two or more regions having different electrode pitches. As a result, a one-aperture surface acoustic wave resonator having multiple attenuation poles is realized.
また、挿入損失の増加やチップサイズの増大を伴わない
で減衰特性を改善するために、複数個の上記１開口弾性
表面波共振器を電気的に直列あるいは並列接続してフィ
ルタを構成したものである。In addition, in order to improve the attenuation characteristics without increasing insertion loss or chip size, a filter is constructed by electrically connecting a plurality of the above single-aperture surface acoustic wave resonators in series or parallel. be.
このとき、各１開口共振器の複数の減衰極周波数と、そ
れらの平均減衰極周波数を適当に設定して、減衰極間の
特性劣化を抑圧したものである。At this time, a plurality of attenuation pole frequencies of each one-aperture resonator and their average attenuation pole frequency are appropriately set to suppress characteristic deterioration between the attenuation poles.
多数対トランスデユーサを電極指ピッチが異なる複数の
領域で構成した、１開口弾性表面波共振器の共振特性は
、複数の電極ピッチに対応した複数の減衰極を有する。The resonance characteristics of a single-aperture surface acoustic wave resonator in which a multi-pair transducer is configured with a plurality of regions having different electrode finger pitches have a plurality of attenuation poles corresponding to a plurality of electrode pitches.
それによって、複数の上記１開口弾性表面波共振器で構
成した共振器複合形フィルタは、１開口共振器の総数に
比べて多数の減衰極を有するために、減衰極間の周波数
差を小さく設定でき、減衰極間の特性劣化を抑圧するこ
とができる。また、従来と同一の共振器数で、減衰極数
の増加が実現されるので、共振器増に伴う挿入損失の増
加、あるいはチップサイズの増大や歩留りの低下などの
問題を解消できる。As a result, since the resonator composite filter composed of a plurality of single-aperture surface acoustic wave resonators has a large number of attenuation poles compared to the total number of single-aperture resonators, the frequency difference between the attenuation poles is set small. This makes it possible to suppress characteristic deterioration between the attenuation poles. Furthermore, since the number of attenuation poles can be increased with the same number of resonators as in the conventional method, problems such as an increase in insertion loss due to an increase in the number of resonators, an increase in chip size, and a decrease in yield can be solved.
以下、本発明の一実施例を第１図により説明する。第１
図（ａ）、（ｂ）は１本発明による１開口弾性表面波共
振器と、そのインピーダンス特性を示す。An embodiment of the present invention will be described below with reference to FIG. 1st
Figures (a) and (b) show a single-aperture surface acoustic wave resonator according to the present invention and its impedance characteristics.
同図（ａ）において、５−１〜２はトランスデユーサの
電極指ピッチがＰｌの領域、６−１〜３は電極指ピッチ
がＰ２の領域である。本実施例ではＰＬ＞Ｐ２の条件に
埋定した場合について説明する。In the figure (a), 5-1 to 2 are regions in which the electrode finger pitch of the transducer is Pl, and 6-1 to 3 are regions in which the electrode finger pitch is P2. In this embodiment, a case where the condition of PL>P2 is satisfied will be explained.
同図（ｂ）の８，９はインピーダンス特性のピークであ
り、８は電極指ピッチＰ１のトランスデユーサによる反
共振点に対応し、９は電極指ピッチＰ２に対応した***
振点である。この場合、トランスデユーサの対数は、電
極指ピッチＰ１とＰ２の領域の総和が同一の対数となる
ように設定してあり、領域５−１．５−２はそれぞれＮ
対。8 and 9 in the figure (b) are peaks of the impedance characteristics, 8 corresponds to the anti-resonance point due to the transducer with the electrode finger pitch P1, and 9 is the anti-resonance point corresponding to the electrode finger pitch P2. In this case, the logarithm of the transducer is set so that the sum of the areas of electrode finger pitches P1 and P2 has the same logarithm, and the areas 5-1 and 5-2 are each N
versus.
領域６−２はＮ対、６−１．６−３はＮ／２対の関係で
ある。したがって、多数対トランスデユーサの総対数が
４００対の場合、Ｎは１００対となる。The area 6-2 has a relationship of N pairs, and the area 6-1.6-3 has a relationship of N/2 pairs. Therefore, if the total number of many-pair transducer pairs is 400, then N is 100 pairs.
第５図は、上記１開口弾性表面波共振器の、入力端子１
から出力端子２に電気信号を通電した場合の振幅周波数
特性である。２９は２種類の電極ピッチで構成した本発
明による特性で、３１゜３２の２つの減衰極を有する。FIG. 5 shows the input terminal 1 of the one-aperture surface acoustic wave resonator.
This is the amplitude frequency characteristic when an electric signal is applied to the output terminal 2 from . Reference numeral 29 indicates a characteristic according to the present invention that is configured with two types of electrode pitches, and has two attenuation poles of 31° and 32°.
３３は本発明の共振器に発生する***振点近傍のリップ
ルである。33 is a ripple generated in the resonator of the present invention near the anti-resonance point.
また、２８は比較のために示した従来構成の場合の特性
である。多数対トランスデユーサが同一ピッチのため、
単一の減衰極３ｏを有する。Further, 28 is the characteristic of the conventional configuration shown for comparison. Because many pairs of transducers have the same pitch,
It has a single attenuation pole 3o.
ｆ８０．ｆ＆□は本実施例の共振器の減衰極周波数、ｆ
＆。は従来構成の共振器の減衰極周波数である。f80. f&□ is the attenuation pole frequency of the resonator in this example, f
&. is the attenuation pole frequency of the conventionally configured resonator.
本実施例の１開口弾性表面波共振器の振幅周波数特性は
、従来構成に比べて、阻止域の帯域幅が広がると共に、
減衰極における減衰量が減少する。The amplitude-frequency characteristics of the one-aperture surface acoustic wave resonator of this example have a wider stopband bandwidth than the conventional configuration, and
The amount of attenuation at the attenuation pole decreases.
以上に述べたように１本発明により、２つの減衰極を有
する１開口弾性表面波共振器が実現される。As described above, according to the present invention, a one-aperture surface acoustic wave resonator having two attenuation poles is realized.
第６図（、）〜（ｅ）は、第１図の実施例と同様に複数
の減衰極周波数を有する１開口弾性表面波共振器の、別
の実施例を簡略して示している。6(a) to 6(e) schematically show another embodiment of a one-aperture surface acoustic wave resonator having a plurality of attenuation pole frequencies, similar to the embodiment of FIG. 1.
同図（ａ）は、２つの減衰極周波数ｆ、工＋ｆａｚを有
する領域が、図中の破線を境界に、それぞれ一つ存在す
る場合、図（ｂ）は３つの領域で構成し、かつ、ｆ ａ
、の領域とｆ ａ２の領域におけるトランスデユーサの
電極対数を同一にした場合、図（ｃ）は減衰極周波数の
関係が図（ｂ）と逆の場合である。また、図（ｄ）は、
さらに領域の数を増加した場合、図（ｅ）は３種類の電
極ピッチで構成して、３つの減衰極周波数を有する場合
である。In the figure (a), there is one region each having two attenuation pole frequencies f and f + faz, with the dashed line in the figure as the boundary, and in the figure (b), there are three regions, and fa
When the number of electrode pairs of the transducer in the region of , and the region of f a2 are made the same, the relationship between the attenuation pole frequencies is reversed in FIG. In addition, figure (d) is
When the number of regions is further increased, Figure (e) shows a case where the electrodes are configured with three types of electrode pitches and have three attenuation pole frequencies.
以上に示した他にも、領域の配置、対数の組合せ、減衰
極周波数の組合せは自由に選択することができる。また
、実施例では減衰極周波数ｆ、□とｆ ＆、の領域にお
けるトランスデユーサの電極対数が同一の場合について
説明したが、対数が異なる場合でも同様の効果を得るこ
とができる。In addition to those shown above, the arrangement of regions, the combination of logarithms, and the combination of attenuation pole frequencies can be freely selected. Further, in the embodiment, a case has been described in which the number of electrode pairs of the transducer in the regions of attenuation pole frequencies f, □ and f & is the same, but the same effect can be obtained even if the number of electrodes is different.
なお、多数の領域に分割して、個々の領域の電極対数が
少数対になった場合は、明確な２つの減衰極が得られず
、共振器全体の平均的な電極ピッチで定まる単一ピーク
の状態に近づく、シたがって、各領域に形成する電極対
数は、少なくとも１０対以上が望ましい。Note that if the number of electrode pairs in each region is small after dividing into many regions, two distinct attenuation poles will not be obtained, and a single peak will be determined by the average electrode pitch of the entire resonator. Therefore, it is desirable that the number of electrode pairs formed in each region be at least 10 or more.
各領域における減衰極周波数の値は、各領域の電極ピッ
チを変えることにより任意に選べるが。The value of the attenuation pole frequency in each region can be arbitrarily selected by changing the electrode pitch in each region.
本発明を適用する弾性表面波フィルタの帯域設計によっ
て決定されるべきものである。また１本発明は特願昭６
３−１７０８９に記載のシリーズ形１開口弾性表面波共
振器のような、他の電極構造においても同様の効果を有
する。This should be determined by the band design of the surface acoustic wave filter to which the present invention is applied. In addition, the present invention was patented in 1986.
Other electrode structures, such as the series-type one-aperture surface acoustic wave resonator described in No. 3-17089, have similar effects.
第７図に、中間電極３４で多数対トランスデユーサを分
割したシリーズ形１開口弾性表面波共振器の構造を一例
として示す。FIG. 7 shows an example of the structure of a series type one-aperture surface acoustic wave resonator in which multiple pairs of transducers are divided by an intermediate electrode 34.
第８図は、本発明のもう一つの実施例で、第１図の構造
の１開口弾性表面波共振器を、第４図と同様に、３個用
いて構成した弾性表面波共振器複合形フィルタである。FIG. 8 shows another embodiment of the present invention, in which a composite surface acoustic wave resonator is constructed using three one-aperture surface acoustic wave resonators having the structure shown in FIG. 1, as in FIG. It's a filter.
図は簡略して、減衰極周波数に対応した領域で示してい
る。１開ロ弾性表面波共振器１３−１〜３の二つの減衰
極周波数は、それぞれｆ工、とＪ工２．ｆ２□とｆ２□
、ｆ、１とｆ。である。The diagram simply shows the region corresponding to the attenuation pole frequency. The two attenuation pole frequencies of the 1-opening surface acoustic wave resonators 13-1 to 13-3 are f, J and 2, respectively. f2□ and f2□
, f, 1 and f. It is.
第９図は、上記弾性表面波共振器複合形フィルタの、阻
止域における振幅周波数特性である。FIG. 9 shows the amplitude frequency characteristics in the stopband of the surface acoustic wave resonator composite filter.
３５〜３７は１開ロ弾性表面波共振器１３−１〜３の単
体特性、３８はこれらの総和として得られる共振器複合
形フィルタの特性、また４０−１〜５は各減衰極周波数
間の減衰量が最小となる部分である。本実施例では、各
減衰極周波数の値を、ｆ １１からｆ３□までの帯域が
ほぼ等分に分割されるように設定しており、このとき４
０−１〜５はほぼ同じ減衰量となる。３９は比較のため
に示した従来構成の場合のフィルタ特性である６二つの
フィルタを、最も減衰特性が劣化する４０−１〜５と４
１−１〜２の部分で比較すると、本実施例の減衰量の方
が大となっている。この減衰量の改善は本発明の効果に
よるものである。35 to 37 are the individual characteristics of the 1-opening surface acoustic wave resonators 13-1 to 3, 38 are the characteristics of the resonator composite filter obtained as the sum of these, and 40-1 to 5 are the characteristics between each attenuation pole frequency. This is the part where the amount of attenuation is minimum. In this example, the value of each attenuation pole frequency is set so that the band from f11 to f3□ is divided into approximately equal parts, and in this case, 4
0-1 to 5 have approximately the same amount of attenuation. 39 shows filter characteristics in the case of a conventional configuration shown for comparison. 6 Two filters are shown in 40-1 to 40-1 to 40-5, which have the worst attenuation characteristics.
Comparing parts 1-1 and 1-2, the amount of attenuation in this example is larger. This improvement in attenuation is due to the effect of the present invention.
第１０図は、第８図と同様のフィルタ構成において、減
衰極周波数の設定に関する別の実施例を示している。４
２〜４４は各１開口弾性表面波共振器の単体特性である
。この場合も、各減衰極はｆ工、からｆ。までの帯域を
、はぼ等分に分割するように設定しである。しかし、４
３の単体特性が有する二つの減衰極間の周波数差Ｃ１，
□−ｆ２□）は、他の周波数差Ｃｆ１□−ｆ工、） 、
Ｃｆ３２−ｆ、、）に比べて大となっている。したが
って、本実施例によるフィルタの特性は、第９図の特性
３８とは正確に一致しないが、はぼ同等の減衰量の改善
効果を得ることができる。また、上記実施例の他にも、
同様の減衰極周波数関係に設定することにより、同等の
効果が得られる。FIG. 10 shows another embodiment regarding the setting of the attenuation pole frequency in a filter configuration similar to that of FIG. 8. 4
2 to 44 are individual characteristics of each one-aperture surface acoustic wave resonator. Again, each attenuation pole is f, to f. The band is set to be divided into approximately equal parts. However, 4
The frequency difference C1 between the two attenuation poles of the single characteristic of 3,
□-f2□) is the other frequency difference Cf1□-f,),
It is larger than Cf32-f, , ). Therefore, although the characteristics of the filter according to this embodiment do not exactly match the characteristics 38 in FIG. 9, it is possible to obtain an effect of improving the amount of attenuation that is approximately the same. In addition to the above embodiments,
Equivalent effects can be obtained by setting similar attenuation pole frequency relationships.
本発明は、各種の構成の弾性表面波共振器複合形フィル
タに適用することができる。その−例として、特願昭６
１−２７８６４２に記載のフィルタ構成を第１１図に示
す。４５−１〜６は１開口弾性表面波共振器の共通電極
、４６−１〜２はギャップ容量用電極、４７−１〜６は
共振器から漏洩した表面波の吸収剤である。同図の共振
器複合形フィルタは、入力端子１からギャップ容量を介
して出力端子２に至る直列腕と、共通電極４５−２．４
５−５から大地に至る並列腕の、それぞれ２個の１開口
弾性表面波共振器により構成した。バンドパスタイプの
フィルタである。これらの１開口弾性表面波共振器に本
発明を実施することにより、減衰特性が改善される。ま
た、同図のフィルタ構成に、第７図のシリーズ形１開口
弾性表面波共振器を適用した場合においても、同様の改
善効果を得ることができる。The present invention can be applied to surface acoustic wave resonator composite filters of various configurations. As an example,
1-278642 is shown in FIG. 11. 45-1 to 6 are common electrodes of the one-aperture surface acoustic wave resonator, 46-1 to 2 are electrodes for gap capacitance, and 47-1 to 6 are absorbers for surface waves leaked from the resonator. The resonator composite filter shown in the figure has a series arm extending from an input terminal 1 to an output terminal 2 via a gap capacitance, and a common electrode 45-2.4.
Each of the parallel arms extending from 5-5 to the ground was composed of two single-aperture surface acoustic wave resonators. It is a bandpass type filter. By applying the present invention to these one-aperture surface acoustic wave resonators, the attenuation characteristics are improved. Further, the same improvement effect can be obtained even when the series-type one-aperture surface acoustic wave resonator shown in FIG. 7 is applied to the filter configuration shown in the same drawing.
本発明の弾性表面波共振器複合形フィルタを、移動無線
端末などの通信装置に用いることにより、装置の性能を
改善することができる。By using the surface acoustic wave resonator composite filter of the present invention in a communication device such as a mobile radio terminal, the performance of the device can be improved.
本発明よれば、複数の減衰極を有する１開口弾性表面波
共振器を実現できる。また、従来と同数の１開口弾性表
面波共振器で、共振器複合形フィルタの減衰特性が改善
されるので、挿入損失の増加やチップサイズの増大を伴
なわずにフィルタの性能を向上できる。さらに、本発明
のフィルタを通信装置に用いることにより、消費電力の
低減をはかることができる。According to the present invention, a one-aperture surface acoustic wave resonator having a plurality of attenuation poles can be realized. Furthermore, since the attenuation characteristics of the resonator composite filter are improved using the same number of single-aperture surface acoustic wave resonators as in the past, the performance of the filter can be improved without increasing insertion loss or chip size. Furthermore, by using the filter of the present invention in a communication device, power consumption can be reduced.
第１図は、本発明の一実施例の１開口弾性表面波共振器
の構造図とインピーダンス特性図、第２図は従来例の１
開口弾性表面波共振器の構造図、第３図（ａ）、（ｂ）
は、第２図の共振器の等価回路とインピーダンス特性図
、第４図（ａ）。
（ｂ）は従来構成の一例の弾性表面波共振器複合形フィ
ルタの構造図とその振幅周波数特性図、第５図は本発明
の実施例による共振器の振幅周波数特性図、第６図は本
発明の１開口弾性表面波共振器の別の実施例の模式的構
成図、第７図はシリーズ形１開口弾性表面波共振器の構
造図、第８図は本発明の一実施例の共振器複合形フィル
タの模式的構成図、第９図、第１０図は本発明の実施例
によるフィルタの振幅周波数特性図、第１１図はバンド
パスタイプの弾性表面波共振器複合形フィルタの構造図
である。
１・・入力端子、２・・・出力端子、３〜４・・・共通
電極、５−１〜２．６−１〜３・・・特定の電極ピッチ
の領域、２９・・・本発明の１開口弾性表面波共振器の
特Ｙ
図
第４図
（の
Ｉｆｆ謔（Ｉ
（Ｈｚ）
ｒ
力
め
図
（α）
（ｂ）
貞
第
図
（久）
（ＩＩ）
（ｂ）
（Ｃ）
■ｌ ｆａｒ Ｉ■
猶
図
固濠廖支 （Ｈ１ンFigure 1 is a structural diagram and impedance characteristic diagram of a one-aperture surface acoustic wave resonator according to an embodiment of the present invention, and Figure 2 is a diagram of a conventional example.
Structural diagram of an aperture surface acoustic wave resonator, Fig. 3 (a), (b)
FIG. 4(a) is an equivalent circuit and impedance characteristic diagram of the resonator in FIG. 2. (b) is a structural diagram and its amplitude-frequency characteristic diagram of a surface acoustic wave resonator composite filter as an example of a conventional configuration, FIG. 5 is an amplitude-frequency characteristic diagram of a resonator according to an embodiment of the present invention, and FIG. 6 is a diagram of the present invention. A schematic configuration diagram of another embodiment of the one-aperture surface acoustic wave resonator of the invention, FIG. 7 is a structural diagram of a series type one-aperture surface acoustic wave resonator, and FIG. 8 is a resonator of an embodiment of the invention. 9 and 10 are amplitude frequency characteristic diagrams of a filter according to an embodiment of the present invention, and FIG. 11 is a structural diagram of a bandpass type surface acoustic wave resonator composite filter. be. DESCRIPTION OF SYMBOLS 1...Input terminal, 2...Output terminal, 3-4...Common electrode, 5-1-2.6-1-3...Specific electrode pitch area, 29...According to the present invention Characteristics of single-aperture surface acoustic wave resonator far I■ Yutu solid moat branch (H1
Claims (3)
対よりなる弾性表面波トランスデューサを弾性表面波の
伝搬方向に配置した弾性表面波共振器において、該弾性
表面波トランスデューサが複数の領域で構成されており
、該領域は複数の交差指電極対が同一ピッチで連続して
配列されてなること、および隣り合った該領域の交差指
電極対のピッチが異なることを特徴とする弾性表面波共
振器。1. In a surface acoustic wave resonator in which a surface acoustic wave transducer consisting of a plurality of pairs of interdigital electrodes is arranged in the propagation direction of the surface acoustic wave on a substrate that propagates surface acoustic waves, the surface acoustic wave transducer is composed of a plurality of regions. surface acoustic wave resonance characterized in that the area is formed by a plurality of pairs of interdigital electrodes arranged consecutively at the same pitch, and the pitches of the pairs of interdigital electrodes in adjacent areas are different. vessel.
面波トランスデューサを構成する複数の領域が、それぞ
れ少なくとも１０対以上の交差指電極対からなることを
特徴とする弾性表面波共振器。2. 2. The surface acoustic wave resonator according to claim 1, wherein each of the plurality of regions constituting the surface acoustic wave transducer comprises at least 10 interdigital electrode pairs.
に直列あるいは並列接続した構成よりなることを特徴と
する弾性表面波共振器複合形フィルタ。3. A surface acoustic wave resonator composite filter comprising the surface acoustic wave resonators according to claim 1 or 2 electrically connected in series or in parallel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25197590A JPH04132409A (en) | 1990-09-25 | 1990-09-25 | Surface acoustic wave resonator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25197590A JPH04132409A (en) | 1990-09-25 | 1990-09-25 | Surface acoustic wave resonator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04132409A true JPH04132409A (en) | 1992-05-06 |
Family
ID=17230786
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25197590A Pending JPH04132409A (en) | 1990-09-25 | 1990-09-25 | Surface acoustic wave resonator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04132409A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09331233A (en) * | 1996-06-12 | 1997-12-22 | Toyo Commun Equip Co Ltd | Surface acoustic wave filter |
| EP1168614A2 (en) * | 2000-06-26 | 2002-01-02 | Murata Manufacturing Co., Ltd. | Longitudinally coupled resonator type surface accoustic wave filter |
| WO2006004199A1 (en) * | 2004-07-06 | 2006-01-12 | Seiko Epson Corporation | Resonator saw filer |
| JP2007013414A (en) * | 2005-06-29 | 2007-01-18 | Seiko Epson Corp | Surface acoustic wave element strip, surface acoustic wave device, and electronic apparatus |
| WO2010047112A1 (en) * | 2008-10-24 | 2010-04-29 | エプソントヨコム株式会社 | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module device |
| JP2010104031A (en) * | 2010-01-09 | 2010-05-06 | Epson Toyocom Corp | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module device |
| JP2013085273A (en) * | 2012-12-11 | 2013-05-09 | Seiko Epson Corp | Surface acoustic wave resonator, surface acoustic wave oscillator and surface acoustic wave module device |
| JP2016517190A (en) * | 2012-12-13 | 2016-06-09 | エプコス アクチエンゲゼルシャフトＥｐｃｏｓ Ａｇ | Electroacoustic bandpass filter with flattened insertion loss. |
| WO2019154655A1 (en) * | 2018-02-08 | 2019-08-15 | RF360 Europe GmbH | Filter circuit with a notch filter |
-
1990
- 1990-09-25 JP JP25197590A patent/JPH04132409A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09331233A (en) * | 1996-06-12 | 1997-12-22 | Toyo Commun Equip Co Ltd | Surface acoustic wave filter |
| EP1168614A2 (en) * | 2000-06-26 | 2002-01-02 | Murata Manufacturing Co., Ltd. | Longitudinally coupled resonator type surface accoustic wave filter |
| WO2006004199A1 (en) * | 2004-07-06 | 2006-01-12 | Seiko Epson Corporation | Resonator saw filer |
| US7579932B2 (en) | 2004-07-06 | 2009-08-25 | Seiko Epson Corporation | Resonator SAW filter having a control interdigital transducer between input and output interdigital transducers |
| JP4743491B2 (en) * | 2005-06-29 | 2011-08-10 | セイコーエプソン株式会社 | Surface acoustic wave element, surface acoustic wave device, and electronic device |
| JP2007013414A (en) * | 2005-06-29 | 2007-01-18 | Seiko Epson Corp | Surface acoustic wave element strip, surface acoustic wave device, and electronic apparatus |
| US8358177B2 (en) | 2008-10-24 | 2013-01-22 | Seiko Epson Corporation | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module unit |
| WO2010047112A1 (en) * | 2008-10-24 | 2010-04-29 | エプソントヨコム株式会社 | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module device |
| JP5163746B2 (en) * | 2008-10-24 | 2013-03-13 | セイコーエプソン株式会社 | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module device |
| US8803625B2 (en) | 2008-10-24 | 2014-08-12 | Seiko Epson Corporation | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module unit |
| JP2010104031A (en) * | 2010-01-09 | 2010-05-06 | Epson Toyocom Corp | Surface acoustic wave resonator, surface acoustic wave oscillator, and surface acoustic wave module device |
| JP2013085273A (en) * | 2012-12-11 | 2013-05-09 | Seiko Epson Corp | Surface acoustic wave resonator, surface acoustic wave oscillator and surface acoustic wave module device |
| JP2016517190A (en) * | 2012-12-13 | 2016-06-09 | エプコス アクチエンゲゼルシャフトＥｐｃｏｓ Ａｇ | Electroacoustic bandpass filter with flattened insertion loss. |
| WO2019154655A1 (en) * | 2018-02-08 | 2019-08-15 | RF360 Europe GmbH | Filter circuit with a notch filter |
| CN111684716A (en) * | 2018-02-08 | 2020-09-18 | Rf360欧洲有限责任公司 | Filter circuit with notch filter |
| US11563422B2 (en) | 2018-02-08 | 2023-01-24 | RF360 Europe GmbH | Filter circuit with a notch filter |
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