JPS6040213B2 - piezoelectric filter - Google Patents
piezoelectric filterInfo
- Publication number
- JPS6040213B2 JPS6040213B2 JP10098579A JP10098579A JPS6040213B2 JP S6040213 B2 JPS6040213 B2 JP S6040213B2 JP 10098579 A JP10098579 A JP 10098579A JP 10098579 A JP10098579 A JP 10098579A JP S6040213 B2 JPS6040213 B2 JP S6040213B2
- Authority
- JP
- Japan
- Prior art keywords
- resonator
- electrode
- piezoelectric
- frequency
- capacitor
- 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
- 239000003990 capacitor Substances 0.000 claims description 12
- 239000000758 substrate Substances 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- 239000000463 material Substances 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
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
- H03H9/56—Monolithic crystal filters
- H03H9/566—Electric coupling means therefor
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic devices; Electromechanical resonators
- H03H9/46—Filters
- H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
- H03H9/56—Monolithic crystal filters
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Description
【発明の詳細な説明】
本発明は圧電７戸波器に関し、より詳しくは多重モード
共振子と単共振子とによって構成した梯子型炉波器（ラ
ダー型フィル夕）の高域側減衰度の改善に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric 7-channel wave generator, and more specifically, to improving the high-frequency side attenuation of a ladder type wave generator (ladder type filter) configured with a multimode resonator and a single resonator. Regarding.
この種のラダー型フィル夕としては、例えば第１図に示
すように、チタン酸ジルコン酸鉛等の圧電材料を四角形
状に焼成加工した一枚の庄電磁器板１に厚み振動エネル
ギー閉じ込め型の三端子型多重モード共振子２および単
一モードで振動する二端子型単共振子３を形成し、多重
モード共振子２の入力側の分割電極２ａは接続電極４を
介して端子電極５に、出力側の分割電極２ｂおよび上記
単共振子３の一方の電極３ａとは接続電極６ａによって
互いに接続するとともに接続電極６ｂを介して端子電極
７に、また、上記単共振子３の他方の電極３ｂは接続電
極８を介して端子電極９に夫々接続し、共通電極２ｃに
はなにも接続しないでおくことにより、第２図に示すよ
うに、上言己多重モード共振子２をその斜対称モード共
振を利用する共振子として、ラダー型フィル夕の直列腕
とする一方、上記単共振子３を並列腕とするようにした
ものが本出願人によって出願されている。For example, as shown in Fig. 1, this type of ladder-type filter is a type that confines vibrational energy through the thickness of a single Sho electromagnetic plate 1 made of a piezoelectric material such as lead zirconate titanate fired into a rectangular shape. A three-terminal multi-mode resonator 2 and a two-terminal single resonator 3 vibrating in a single mode are formed, and the split electrode 2a on the input side of the multi-mode resonator 2 is connected to the terminal electrode 5 via the connecting electrode 4. The divided electrode 2b on the output side and one electrode 3a of the single resonator 3 are connected to each other by a connecting electrode 6a, and to the terminal electrode 7 via the connecting electrode 6b, and the other electrode 3b of the single resonator 3 is connected to the terminal electrode 7 via the connecting electrode 6b. are respectively connected to the terminal electrodes 9 via the connection electrodes 8, and are not connected to the common electrode 2c, thereby making the multimode resonator 2 with its diagonal symmetry as shown in FIG. As a resonator utilizing mode resonance, the present applicant has applied for a resonator in which the series arm of a ladder type filter is used, and the single resonator 3 is used in parallel arms.
一枚の圧電基板にフィル夕の直列腕、並列腕を設ける場
合、上記のようにすれば、多重モード共振子２の斜対称
モード振動が単共振子３の場合よりも高い共振周波数お
よび反共振周波数を有しているため、容易に、比較的広
い通過帯域中を得ることができるが、上記多車モード共
振子および単共振子３はいずれも一枚の圧電磁器板１上
に形成されて同一の厚み振動モードで振動するため、上
記多重モード共振子２および単共振子３の各共振周波数
および反共振周波数を独立して設計することが困難で、
例えば、中心周波数が１０．７ＭＨＺのＦＭ中間周波増
中器のフィルタに適用した場合について、第３図に曲線
１．に示すように、高城側の減衰暖か甘くなる問題があ
った。本発明は従来の圧電炉波器における上記問題を解
消すべくなされたものであって、一枚の圧電基板に形成
した多重モード共振子および単共振子を夫々直列腕およ
び並列腕とする梯子型炉波器の直列腕の入力側と出力側
との間にコンデンサを接続し、高域側ポールを形成する
直列腕の反共振周波数を低下させることにより、高城側
減衰度の改善を図り、減衰特性の対称性を向上させた圧
電炉波器を提供することを目的としている。When providing series arms and parallel arms of a filter on a single piezoelectric substrate, if the above steps are taken, the obliquely symmetrical mode vibration of the multimode resonator 2 will be higher than that of the single resonator 3, and the resonant frequency will be higher than that of the single resonator 3. frequency, it is possible to easily obtain a relatively wide passband, but both the multi-vehicle mode resonator and the single resonator 3 are formed on a single piezoelectric ceramic plate 1. Since they vibrate in the same thickness vibration mode, it is difficult to independently design each resonant frequency and anti-resonant frequency of the multimode resonator 2 and single resonator 3,
For example, when applied to the filter of an FM intermediate frequency intensifier with a center frequency of 10.7 MHz, curve 1. As shown in the figure, there was a problem with the attenuation of the Takagi side becoming warmer and sweeter. The present invention has been made to solve the above-mentioned problems in conventional piezoelectric wave generators, and is a ladder type resonator in which a multi-mode resonator and a single resonator formed on a single piezoelectric substrate are used as series arms and parallel arms, respectively. By connecting a capacitor between the input side and the output side of the series arm of the reactor wave generator, and lowering the anti-resonance frequency of the series arm that forms the high frequency side pole, the degree of attenuation on the high side side is improved and the attenuation is reduced. The purpose of this invention is to provide a piezoelectric wave generator with improved symmetry of characteristics.
以下、本発明の実施例を示す図面を参照して詳細に説明
する。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
本発明においては、例えば、第１図のラダ−型フィル夕
を使用する場合、第４図に示すように、多重モード共振
子の入力側の分割電極２ａに導適する端子電極５と、単
共振子３の一方の電極を介して多重モード共振子の出力
側の分割電極２ｂに導適する端子電極７との間にコンデ
ンサＣを接続するようにしている。In the present invention, for example, when using the ladder type filter shown in FIG. 1, as shown in FIG. A capacitor C is connected between one electrode of the child 3 and a terminal electrode 7 which is conductive to the divided electrode 2b on the output side of the multimode resonator.
圧電炉波器を上記構成とすれば、第５図に示すように、
多重モード共振子２および単共振子３を夫々直列腕およ
び並列腕とするラダー型フィル夕の上記直列腕の入力側
と出力側との間をコンデンサＣで橋絡した回路構成とな
り、高城側ポールを形成する上記多重モード共振子２の
斜対称モード共振を利用する共振子の反共振周波数が低
下し、上記圧電炉波器の減衰域の高域側の減衰度が大き
くなる。If the piezoelectric wave generator has the above configuration, as shown in FIG.
The circuit configuration is such that a capacitor C bridges the input side and output side of the series arm of a ladder type filter in which the multimode resonator 2 and the single resonator 3 are the series arm and the parallel arm, respectively. The anti-resonance frequency of the resonator that utilizes the obliquely symmetrical mode resonance of the multi-mode resonator 2 forming the piezoelectric wave generator decreases, and the degree of attenuation on the high-frequency side of the attenuation range of the piezoelectric wave generator increases.
ちなみに、圧電磁器板１として、厚さ２０５仏肌のＰＺ
Ｔ系のものを使用し、分割電極２ａ，２ｂの長さａおよ
びｂをａ＝０．８柵，ｂ＝０．４５側、上記分割電極２
ａと２ｂとの間のギャップｇをｇ＝０．２脚、共通電極
２ｃの寸法を（１．１肋）×（０．８伽）とし、単共振
子３の電極３ａ，３ｂの直径を夫々０．９側めとする一
方、コンデンサＣの容量をＣ＝６．８ｐＦとして減衰特
性を測定すれば、第３図において曲線１２で示すような
特性が得られる。By the way, the piezoelectric ceramic plate 1 is made of PZ with a thickness of 205 mm.
T-type electrodes are used, and the lengths a and b of the divided electrodes 2a and 2b are set to a = 0.8 fence, b = 0.45 side, and the above divided electrode 2.
The gap g between a and 2b is g = 0.2 feet, the dimensions of the common electrode 2c are (1.1 ribs) x (0.8 feet), and the diameters of the electrodes 3a and 3b of the single resonator 3 are If the attenuation characteristics are measured with the capacitance of the capacitor C set to C=6.8 pF while each is on the 0.9 side, a characteristic as shown by curve 12 in FIG. 3 is obtained.
上記第３図から明らかなように、第１図のラダー型フィ
ル夕では、高城側の減衰極Ｐ，の周波数が１１．１７８
ＭＨ２であるのに対して、第４図のラダー型フィル夕で
は、高域側の減衰極Ｐ２の周波数が１１．０１９Ｍ日２
と低域側に移動しており、高域側の減衰特性が改善され
ていることが分る。なお、コンデンサＣの容量は、中心
周波数が１０．７ＭＨ２の場合、数ＰＦ〜ｌＯＰＦ程度
である。また、減衰極がＰ．からＰ２に移動することに
より、第１図のラダー型フィル夕のシェープフアク夕（
＝減衰極間々隔／紅Ｂ帯域中）では、（１１．１７５一
１０．４４）／（１０．９１−１０．５９５）±２．３
５となるのに対し、第４図のラダー型フィル夕では、シ
ェープフアクタは（１１．０１５−１０．４４）／（１
０．８５一１０．５９）＝２．１３となり、減衰特性も
対称となる。As is clear from Fig. 3 above, in the ladder type filter shown in Fig. 1, the frequency of the attenuation pole P on the Takagi side is 11.178.
MH2, whereas in the ladder type filter shown in Fig. 4, the frequency of the attenuation pole P2 on the high frequency side is 11.019Mday2.
It can be seen that the attenuation characteristics on the high frequency side have been improved. Note that the capacitance of the capacitor C is approximately several PF to lOPF when the center frequency is 10.7 MH2. Also, the attenuation pole is P. By moving from to P2, the shape factor (
= Attenuation pole spacing/Red B band) is (11.175 - 10.44) / (10.91 - 10.595) ± 2.3
5, whereas in the ladder type filter shown in Figure 4, the shape factor is (11.015-10.44)/(1
0.85 - 10.59) = 2.13, and the attenuation characteristics are also symmetrical.
以上の説明において本発明の基本的な実施例について説
明したが、本発明は上記実施例に限定されるものではな
く、例えば、コンデンサＣは電極端子５と７との間に外
付けする代りに、圧電磁器板１上に多重モード共振子２
等とともに一体に形成するようにしてもよい。その具体
的構造は従来公知のいかなるものでも適用可能である。
また、一枚の圧電磁器板１に２セクション以上のラダー
型フィル夕を多段に形成したものにも適用することもで
きる。以上、詳細に説明したことからも明らかなように
、本発明は多重モード共振子によって形成した梯子型炉
波器の直列腕の入力側と出力側との間にコンデンサを接
続し、高城側ポ−ルを形成する直列腕の反共振周波数を
低下させるようにしたかり、コンデンサを接続するだけ
で比較的簡単に梯子型炉波器の高域側減衰度が大きくな
って、減衰特性の対称性を向上させることができる。Although the basic embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, instead of connecting the capacitor C externally between the electrode terminals 5 and 7, , a multimode resonator 2 on a piezoelectric ceramic plate 1
It may be formed integrally with the other components. Any conventionally known specific structure can be used.
Furthermore, the present invention can also be applied to a structure in which two or more sections of ladder-type filters are formed in multiple stages on a single piezoelectric ceramic plate 1. As is clear from the above detailed explanation, the present invention connects a capacitor between the input side and the output side of the series arm of a ladder type reactor waver formed by a multimode resonator, and connects a capacitor to the Takagi side port. - We want to lower the anti-resonance frequency of the series arms that form the loop, and we can relatively easily increase the high-frequency attenuation of the ladder-type reactor by simply connecting a capacitor, thereby improving the symmetry of the attenuation characteristics. can be improved.
また、上記コンデンサにより上記直列腕の反共振周波数
を変化させるため、二重モード共振子および単共振子の
周波数配置の設計も容易となる。Further, since the anti-resonance frequency of the series arm is changed by the capacitor, it becomes easy to design the frequency arrangement of the double mode resonator and the single resonator.
第１図は従釆の圧電炉波器の斜視図、第２図は第１図の
等価回路図、第３図は第１図および第４図の炉波器の減
衰特性図、第４図は本発明に係る圧電炉波器の斜視図、
第５図は第４図の等価回路図である。
１・・・・・・圧電磁器板、２・・・・・・多重モード
共振子（２ａ，２ｂ…・・・分割電極）、３・…・・単
共振子、５，７，９・・・・・・端子電極、Ｃ・・・・
・・コンデンサ。
第１図第２図
第４図
第５図Figure 1 is a perspective view of a secondary piezoelectric wave generator, Figure 2 is an equivalent circuit diagram of Figure 1, Figure 3 is a diagram of the attenuation characteristics of the wave generator shown in Figures 1 and 4, and Figure 4. is a perspective view of a piezoelectric wave device according to the present invention,
FIG. 5 is an equivalent circuit diagram of FIG. 4. 1...Piezoelectric ceramic plate, 2...Multi-mode resonator (2a, 2b...divided electrode), 3...Single resonator, 5, 7, 9... ...Terminal electrode, C...
...Capacitor. Figure 1 Figure 2 Figure 4 Figure 5
Claims (1)
ド共振子と単共振子とを少くとも一対形成し、上記多重
モード共振子をその斜対称モード共振を利用する共振子
として梯子型濾波器の直列腕とする一方、上記単共振子
を並列腕とするようにした濾波器において、上記直列腕
の入力側と出力側との間にコンデンサを接続したことを
特徴とする圧電濾波器。1. At least one pair of an energy-trapped multimode resonator and a single resonator are formed on one piezoelectric substrate, and the multimode resonator is used as a resonator that utilizes its obliquely symmetrical mode resonance, and a ladder filter is connected in series. 1. A piezoelectric filter in which the single resonator is used as an arm and the single resonator is used as a parallel arm, characterized in that a capacitor is connected between an input side and an output side of the series arm.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10098579A JPS6040213B2 (en) | 1979-08-07 | 1979-08-07 | piezoelectric filter |
| US06/113,449 US4287493A (en) | 1979-01-25 | 1980-01-21 | Piezoelectric filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10098579A JPS6040213B2 (en) | 1979-08-07 | 1979-08-07 | piezoelectric filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5624821A JPS5624821A (en) | 1981-03-10 |
| JPS6040213B2 true JPS6040213B2 (en) | 1985-09-10 |
Family
ID=14288608
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10098579A Expired JPS6040213B2 (en) | 1979-01-25 | 1979-08-07 | piezoelectric filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6040213B2 (en) |
-
1979
- 1979-08-07 JP JP10098579A patent/JPS6040213B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5624821A (en) | 1981-03-10 |
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