JPS6217412B2 - - Google Patents
Info
- Publication number
- JPS6217412B2 JPS6217412B2 JP7297978A JP7297978A JPS6217412B2 JP S6217412 B2 JPS6217412 B2 JP S6217412B2 JP 7297978 A JP7297978 A JP 7297978A JP 7297978 A JP7297978 A JP 7297978A JP S6217412 B2 JPS6217412 B2 JP S6217412B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- basic configuration
- configuration section
- oscillator
- gradually
- 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
- 238000000034 method Methods 0.000 claims description 4
- 230000007423 decrease Effects 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
Landscapes
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Description
【発明の詳細な説明】
本発明は多素子で構成される梯子型圧電フイル
タに係り、その目的は周波数の異なる圧電振動子
を組み合わせてフイルタを実現することにある。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ladder-type piezoelectric filter composed of multiple elements, and its purpose is to realize a filter by combining piezoelectric vibrators having different frequencies.
本発明の結果にしたがえば、圧電振動子の周波
数微調整が不要となり、大量かつ安価に梯子型圧
電フイルタの提供が可能となる。 According to the results of the present invention, fine adjustment of the frequency of the piezoelectric vibrator becomes unnecessary, and it becomes possible to provide ladder-type piezoelectric filters in large quantities and at low cost.
従来、第１図に示すような梯子型フイルタを設
計する場合、直列に配置される振動子A1，A2，
…Ａnの共振周波数と並列に配置される振動子
B1，B2…Ｂoの反共振周波数をフイルタの中心周
波数０においてすべて一致させることが特徴で
あり、０においてインピーダンス整合をとつて
いる。したがつてこれは直列に配置される圧電振
動子Ａの共振周波数と並列に配置される圧電振動
子Ｂの反共振周波数を一致させるという性格のも
のであるからフイルタに組み込む振動子の周波数
は０近傍に限られ、０からなり離れると通過
域に大きなリツプルが生じ、相当数の振動子を周
波数調整する必要があつた。 Conventionally, when designing a ladder-type filter as shown in Fig. 1, oscillators A 1 , A 2 ,
...An oscillator placed in parallel with the resonant frequency of A n
The feature is that the anti-resonance frequencies of B 1 , B 2 . . . B o all match at the filter center frequency 0 , and impedance matching is achieved at 0 . Therefore, since this is to match the resonant frequency of piezoelectric vibrator A arranged in series with the anti-resonance frequency of piezoelectric vibrator B arranged in parallel, the frequency of the vibrator incorporated in the filter is 0. It is limited to the vicinity, and when it is far from 0 , large ripples occur in the passband, making it necessary to adjust the frequency of a considerable number of oscillators.
455KHzの中間周波フイルタはPZT系圧電磁器
の円板あるいは角板の拡がり振動を利用した梯子
型フイルタが数多く実用化されている。 Many 455KHz intermediate frequency filters have been put into practical use, such as ladder-type filters that utilize the spreading vibration of PZT-based piezoelectric ceramic discs or square plates.
このフイルタを例にとれば、例えば円板振動子
の場合には、あらかじめ所望の周波数より低くな
るように造つておき、円周部を研摩して共振周波
数を高くして所望の値に周波数調整する方法がと
られている。また角板振動子の場合には、辺を研
摩して周波数を上げたり、あるいは辺の中央部に
切り欠きを設けて周波数を下げる方法で調整が行
なわれている。 Taking this filter as an example, for example, in the case of a disc resonator, it is made in advance to have a lower frequency than the desired frequency, and the circumference is polished to raise the resonant frequency and the frequency is adjusted to the desired value. A method is being taken to do so. In the case of a square plate vibrator, adjustment is carried out by polishing the sides to increase the frequency, or by providing a cutout in the center of the side to lower the frequency.
圧電磁器では、原料や製造ロツトが変わると音
速が変化することが避けられないこと、また円板
あるいは角板の寸法の加工精度でも共振周波数が
若干変化するので、前述のような周波数調整は必
要不可欠の工程と考えられてきた。 In piezoelectric ceramics, the speed of sound inevitably changes when the raw material or manufacturing lot changes, and the resonant frequency changes slightly depending on the machining accuracy of the disc or square plate dimensions, so frequency adjustment as described above is necessary. It has been considered an essential process.
このような周波数調整は多数の人手と高額な設
備が必要であり、量産時における障害になると同
時に梯子型フイルタを高価なものにする大きな要
因であつた。 Such frequency adjustment requires a large number of manpower and expensive equipment, which is a hindrance in mass production and is a major factor in making ladder filters expensive.
これに対し本発明によるフイルタは、第２図に
示すように直列に配置される振動子Ａi，Ａi+1，
…，Ａi+nを順に共振周波数r(Ai)，r(Ai+1)，
……，r(Ai+n)，並列に配置される振動子Ｂk，
Ｂk+1，……，Ｂk+oを順に反共振周波数a(Bk)，
a(Bk+1)，……，Ｂk+oを順に反共振周波数a(B
ｋ），a(Bk+1)，……，a(Bk+o)とすると、直列
に配置される振動子についてr(Ai)＞r(Ai+1)＞
……＞r(Ai+n)としたときに並列に配置される
振動子についてa(Bk)＞a(Bk+1)＞……＞a(B
ｋ＋ｏ）に設定し、また逆にr(Ai)＜r(Ai+1)＜……
＜r(Ai+n)としたときにa(Bk)＜a(Bk+1)＜…
…＜a(Bk+o)に設定し、これを基本構成区間と
する。一方前記基本構成区間に縦続接続される基
本構成区間は、前段にある区間が入力側から順次
周波数が高くなるように設定されている場合には
順次周波数が低くなるように振動子を配置し、今
度は逆に前段にある区間が入力側から順次周波数
が低くなるように設定されている場合には順次周
波数が高くなるように振動子を配置し、その接続
点において前段の最後尾の振動子とそれに続く後
段の最初の振動子とは比較的近接した周波数に設
定することを特徴とするものである。したがつて
本発明によれば、各基本区間の周波数が互に異な
ることが特徴であるため、製造条件のばらつきに
よつて生ずる各振動子の周波数のばらつきは、周
波数調整をして何ら補正する必要がなくなり、上
記従来フイルタ構成法の欠点を除くことが可能と
なり工業的価値は多大である。 On the other hand, the filter according to the present invention has vibrators A i , A i+1 , and
..., A i+n in order as resonant frequency r(Ai) , r(Ai+1) ,
..., r(Ai+n) , oscillators B k arranged in parallel,
B k+1 , ..., B k+o in order as anti-resonant frequency a(Bk) ,
a(Bk+1) , ..., B k+o in order as anti-resonant frequency a(B
k) , a(Bk+1) , ..., a(Bk+o) , then r(Ai) ＞ r(Ai+1) ＞ for the oscillators arranged in series.
……＞ r(Ai+n) For the oscillators arranged in parallel, a(Bk) ＞ a(Bk+1) ＞……＞ a(B
k+o) , and conversely r(Ai) < r(Ai+1) <...
When ＜ r(Ai+n) , a(Bk) ＜ a(Bk+1) ＜…
...< a(Bk+o) , and make this the basic configuration interval. On the other hand, in the basic configuration section connected in cascade to the basic configuration section, if the section in the previous stage is set so that the frequency increases sequentially from the input side, the oscillators are arranged so that the frequency decreases sequentially, This time, conversely, if the frequency of the section in the previous stage is set to decrease sequentially from the input side, the transducers are arranged so that the frequency increases sequentially, and at the connection point, the last transducer in the previous stage The first transducer and the first transducer in the succeeding stage are characterized by being set at relatively close frequencies. Therefore, according to the present invention, since the frequencies of each basic section are different from each other, variations in the frequency of each vibrator caused by variations in manufacturing conditions can be corrected by frequency adjustment. This eliminates the need for this method, and it becomes possible to eliminate the drawbacks of the conventional filter construction method described above, which is of great industrial value.
次に本発明の一例として、第３図に示す中心周
波数が455KHzで角板状PZT系圧電磁器から構成
した９素子梯子型フイルタについて説明する。第
３図で直列に配置される振動子a1，a2，a3，a4，
a5はすべて並列容量C0の値が75pF、共振反共振
周波数差△の値が10.8KHz、振動子の機械的Ｑ
nの値が1500であり、並列に配置される振動子
b1，b2，b3，b4はすべてC0が600pF、△が
10.3KHz、Ｑn1500となつている。またa1，a2，a3
の共振周波数をそれぞれ454.0，455.0，456.0K
Hz、b1，b2の反共振周波数をそれぞれ454.3，
455.3KHzに設定しこれを第１基本構成区間とす
る。次にそれに接続される第２基本構成区間につ
いて、振動子a4，a5の共振周波数をそれぞれ
455.4，454.4KHz，振動子b4，b5の反共振周波数
についてそれぞれ455.6，454.6KHzに設定した。 Next, as an example of the present invention, a nine-element ladder-type filter shown in FIG. 3 having a center frequency of 455 KHz and constructed from square plate-shaped PZT-based piezoelectric ceramics will be described. In Fig. 3, the oscillators a 1 , a 2 , a 3 , a 4 , arranged in series,
A 5 is all parallel capacitance C 0 value is 75pF, resonance anti-resonance frequency difference △ value is 10.8KHz, mechanical Q of the resonator
The value of n is 1500 and the oscillators are arranged in parallel
b 1 , b 2 , b 3 , b 4 all have C 0 of 600 pF and △
It is 10.3KHz, Q n 1500. Also a 1 , a 2 , a 3
The resonant frequencies of 454.0, 455.0, and 456.0K, respectively.
Hz, anti-resonant frequencies of b 1 and b 2 are respectively 454.3,
It is set to 455.3KHz and this is the first basic configuration section. Next, for the second basic configuration section connected to it, the resonant frequencies of oscillators a 4 and a 5 are determined respectively.
The anti-resonance frequencies of vibrators b 4 and b 5 were set to 455.4 and 454.4 KHz, respectively, and 455.6 and 454.6 KHz.
本フイルタの通過域動作減衰量特性を第４図に
実線で示す。また同図の点線はC0，△，Ｑnを
前記実施例に等しくし、直列に配置される振動子
a1，a2，a3，a4，a5の共振周波数と並列に配置さ
れる振動子b1，b2，b3，b4の反共振周波数を等し
く455.0KHzに調整したときのフイルタ特性を示
している。両者がほとんど一致することが認めら
れる。 The passband operation attenuation characteristic of this filter is shown by a solid line in FIG. In addition, the dotted line in the same figure shows the oscillators arranged in series with C 0 , △, and Q n equal to those in the previous embodiment.
Filter when the resonant frequencies of a 1 , a 2 , a 3 , a 4 , and a 5 and the anti-resonant frequencies of the vibrators b 1 , b 2 , b 3 , and b 4 arranged in parallel are adjusted to 455.0 KHz. It shows the characteristics. It is recognized that the two are almost identical.
また同図中の一点鎖線は、本発明の一例として
用いた振動子をそのまま使用して、その配列を直
列に配置された振動子どおし、並列に配置された
振動子どおしで、本発明にしたがわない全くラン
ダムな形で行なつたときの通過域特性を示してい
る。 In addition, the dashed-dotted line in the figure shows the arrangement of the transducers used as an example of the present invention, with the transducers arranged in series and the transducers arranged in parallel. It shows the passband characteristics when performed in a completely random manner not according to the invention.
以上の実施例から明らかなように、周波数の異
なつた振動子を無作意に組み合わせれば、フイル
タの通過域特性が乱れ大きなリツプルが生じる。
これに対して本発明にしたがう配列をとれば、通
過域が乱れずに各振動子を455.0KHzに周波数調
整したフイルタと全く同等の特性を得ることがで
きる。 As is clear from the above embodiments, if vibrators with different frequencies are randomly combined, the passband characteristics of the filter will be disturbed and large ripples will occur.
On the other hand, if the arrangement according to the present invention is adopted, it is possible to obtain characteristics completely equivalent to a filter in which the frequency of each vibrator is adjusted to 455.0 KHz without disturbing the passband.
したがつて、本発明によれば、振動子の周波数
許容幅を著るしく増大せしめ、低廉価、高性能の
梯子型圧電フイルタの製造が可能となり、その工
業的価値は多大である。 Therefore, according to the present invention, the frequency tolerance range of the vibrator is significantly increased, and a low-cost, high-performance ladder-type piezoelectric filter can be manufactured, which has great industrial value.
第１図は梯子型圧電フイルタの電気的結線図
で、A1，A2，……，Ａnは直列に配置される振動
子、B1，B2，……，Ｂoは並列に配置される振動
子を示す。第２図は本発明の基本構成区間を示
し、Ａi，Ａi+1，……，Ａi+nは直列に配置される
振動子、Ｂk，Ｂk+1，……，Ｂk+oは並列に配置さ
れる振動子である。第３図は実施例で用いた９素
子梯子型圧電フイルタの結線図で、a1，a2，a3，
a4，a5は直列に配置される振動子、b1，b2，b3，
b4は並列に配置される振動子を示す。第４図は実
施例で用いた９素子梯子型圧電フイルタの通過域
動作減衰量特性を示し、実線は本発明にしたがつ
た場合の特性、点線はa1，a2，a3，a4，a5の各振
動子の共振周波数およびb1，b2，b3，b4の各振動
子の反共振周波数を455.0KHzに一致させた場合
の特性、また一点鎖線は本発明による実施例と同
じ周波数設定において配列の仕方を本発明にした
がわないでa1，a2，a3，a4，a5の各振動子および
b1，b2，b3，b4の各振動子どおしを全くランダム
な形に配列した場合の特性を示す。
Figure 1 is an electrical connection diagram of a ladder-type piezoelectric filter, where A 1 , A 2 , ..., A n are vibrators arranged in series, and B 1 , B 2 , ..., B o are arranged in parallel. The oscillator shown is shown below. FIG. 2 shows the basic configuration sections of the present invention, where A i , A i+1 , ..., A i+n are oscillators arranged in series, B k , B k+1 , ..., B k +o is an oscillator placed in parallel. Figure 3 is a wiring diagram of the 9-element ladder-type piezoelectric filter used in the example, in which a 1 , a 2 , a 3 ,
a 4 , a 5 are vibrators arranged in series, b 1 , b 2 , b 3 ,
b 4 indicates oscillators arranged in parallel. FIG. 4 shows the passband operation attenuation characteristics of the 9-element ladder-type piezoelectric filter used in the example, where the solid line is the characteristic according to the present invention, and the dotted line is a 1 , a 2 , a 3 , a 4 , a 5 , and the anti-resonance frequency of each vibrator b 1 , b 2 , b 3 , b 4 are matched to 455.0 KHz, and the dashed-dotted line shows an example according to the present invention. At the same frequency setting, each vibrator a 1 , a 2 , a 3 , a 4 , a 5 and
The characteristics are shown when the vibrators b 1 , b 2 , b 3 , and b 4 are arranged in a completely random manner.
Claims (1)
側から順に次第に高くなるように配列するか、あ
るいは低くなるように配列しかつ並列に配置され
る振動子について反共振周波数を同様に入力側か
ら直列に配置される振動子の共振周波数の配列方
向と同じく、次第に高くなるように配列するか低
くなるように配列したものを基本構成区間ｉと
し、それに縦続に接続される基本構成区間ｉ＋１
と基本構成区間ｉとの接続点において、基本構成
区間ｉの最後尾の振動子の周波数と、基本構成区
間ｉ＋１の最初の振動子の周波数を比較的近接し
た値に設定し、さらに基本構成区間ｉの振動子に
ついて入力側から周波数が次第に高くなるように
配列した場合基本構成区間ｉ＋１の振動子につい
て周波数が次第に低くなるように配列し、あるい
は逆に基本構成区間ｉについて次第に周波数が低
くなるように配列した場合、基本構成区間ｉ＋１
について次第に周波数が高くなるように配列し、
このようにして多段に接続することを特徴とする
梯子型圧電フイルタの構成法。1. Arrange the resonant frequencies of the transducers arranged in series so that they gradually increase from the input side, or arrange them so that they become lower, and similarly increase the anti-resonant frequencies of the transducers arranged in parallel from the input side. The basic configuration section i is one in which the resonant frequencies of the vibrators arranged in series are arranged so as to gradually become higher or lower, in the same direction as the arrangement direction, and the basic configuration section i+1 is connected in cascade to it.
At the connection point between basic configuration section i, the frequency of the last oscillator of basic configuration section i and the frequency of the first oscillator of basic configuration section i+1 are set to relatively close values, and If the oscillator in i is arranged so that the frequency gradually increases from the input side, the oscillator in basic configuration section i+1 is arranged so that the frequency gradually decreases, or conversely, the frequency becomes gradually lower in basic configuration section i. , the basic configuration interval i+1
Arranged so that the frequency gradually increases,
A method of configuring a ladder-type piezoelectric filter characterized by connecting it in multiple stages in this way.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7297978A JPS54163654A (en) | 1978-06-15 | 1978-06-15 | Method of constituting ladderrtype piezooelectric felter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7297978A JPS54163654A (en) | 1978-06-15 | 1978-06-15 | Method of constituting ladderrtype piezooelectric felter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS54163654A JPS54163654A (en) | 1979-12-26 |
| JPS6217412B2 true JPS6217412B2 (en) | 1987-04-17 |
Family
ID=13505006
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7297978A Granted JPS54163654A (en) | 1978-06-15 | 1978-06-15 | Method of constituting ladderrtype piezooelectric felter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS54163654A (en) |
-
1978
- 1978-06-15 JP JP7297978A patent/JPS54163654A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54163654A (en) | 1979-12-26 |
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