JPS622725B2 - - Google Patents
Info
- Publication number
- JPS622725B2 JPS622725B2 JP53117138A JP11713878A JPS622725B2 JP S622725 B2 JPS622725 B2 JP S622725B2 JP 53117138 A JP53117138 A JP 53117138A JP 11713878 A JP11713878 A JP 11713878A JP S622725 B2 JPS622725 B2 JP S622725B2
- Authority
- JP
- Japan
- Prior art keywords
- surface acoustic
- reflection
- converter
- acoustic wave
- reflection grating
- 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
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
- H03H9/46—Filters
- H03H9/64—Filters using surface acoustic waves
- H03H9/6406—Filters characterised by a particular frequency characteristic
- H03H9/6413—SAW comb filters
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
- H03H9/02—Details
- H03H9/02535—Details of surface acoustic wave devices
- H03H9/02637—Details concerning reflective or coupling arrays
- H03H9/02685—Grating lines having particular arrangements
- H03H9/02716—Tilted, fan shaped or slanted grating lines
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H2250/00—Indexing scheme relating to dual- or multi-band filters
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】
本発明は複数周波数通過型の弾性表面波フイル
ターに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a surface acoustic wave filter that passes multiple frequencies.
本発明の目的は、複数の狭帯域パスバンドを持
つフイルターを安価に供給することである。 It is an object of the invention to provide a filter with multiple narrow passbands at low cost.
従来、複数の狭帯域パスバンドが必要とされる
多チヤンネル通信器には、複数個の圧電共振子を
切り換えて用いる場合が一般的であるが、多くの
圧電共振子が必要となり、コストアツプ、寸法増
大などの欠点がある。このため、最近ではフエイ
ズロツクループの適用により、数少ない圧電共振
子を用いるのみで多チヤンネルの通信が可能とな
つてきたが、回路構成が第１図に示す如く複雑で
あるため、コストアツプにつながる。 Conventionally, in multi-channel communication devices that require multiple narrow passbands, it is common to use multiple piezoelectric resonators by switching between them. There are drawbacks such as increased size. For this reason, in recent years, the application of phase lock loops has made it possible to perform multi-channel communication using only a few piezoelectric resonators, but the circuit configuration is complex as shown in Figure 1, leading to increased costs. .
第１図はフエイズロツクループを適用した多チ
ヤンネル通信器用の複数周波数発生器のブロツク
図を示す。第１図において、１は圧電共振子の発
振回路、２は可変分周比を有する分周回路、３は
混合回路、４は低域漏波器、５は電圧制御発振回
路、６は周波数逓倍回路、７は可変分周比を有す
る分周回路、８は増巾器である。 FIG. 1 shows a block diagram of a multi-frequency generator for a multi-channel communication device using a phase lock loop. In Fig. 1, 1 is a piezoelectric resonator oscillation circuit, 2 is a frequency divider circuit with a variable frequency division ratio, 3 is a mixing circuit, 4 is a low-frequency leaker, 5 is a voltage-controlled oscillation circuit, and 6 is a frequency multiplier. 7 is a frequency dividing circuit having a variable frequency division ratio, and 8 is an amplifier.
本発明はかかる欠点を除した通信器を実現させ
るための複数周波数通過型の弾性表面波フイルタ
ーである。 The present invention is a surface acoustic wave filter that passes multiple frequencies to realize a communication device that eliminates such drawbacks.
この実施例を第２図に示す。第２図において、
９は圧電体もしくは表面に圧電体層を有する基
体、１０は送波変換器、１１は受波変換器、１
２，１３，１４，１５は弾性表面波の反射格子
で、反射格子を構成する各反射器は弾性表面波の
伝搬方向に対し図の如く45゜の角度に設けられ
る。弾性表面波は反射格子１２，１３，１４，１
５で順次反射され、反射ループを構成するもので
ある。反射格子１４で反射され送波変換器と受波
変換器とを結ぶ伝搬路上に戻された弾性表面波
は、反射格子１５により送波変換器１０と受波変
換器１１とを結ぶ伝搬路上で干渉する。前記反射
ループは無限に繰り返されるため多重干渉構造と
なるのである。又、各反射格子の傾斜角度を伝搬
方向に対して45゜にしたのは、反射波振幅の低下
がなく反射効率が良好で、多重干渉による効果が
大きいためである。又、反射格子に対する弾性表
面波の入射角は45゜と言えるので、反射角は90゜
になる。反射格子１２，１５は送波変換器１０と
受波変換器を結ぶ弾性表面波の伝搬路上に設けら
れる。 This embodiment is shown in FIG. In Figure 2,
9 is a piezoelectric body or a base having a piezoelectric layer on the surface; 10 is a transmitting transducer; 11 is a receiving transducer;
Numerals 2, 13, 14, and 15 are reflection gratings for surface acoustic waves, and each reflector constituting the reflection grating is provided at an angle of 45° with respect to the propagation direction of the surface acoustic waves, as shown in the figure. For surface acoustic waves, reflection gratings 12, 13, 14, 1
5 and constitutes a reflection loop. The surface acoustic wave reflected by the reflection grating 14 and returned to the propagation path connecting the transmitting converter and the receiving converter 11 is reflected by the reflecting grating 15 onto the propagation path connecting the transmitting converter 10 and the receiving converter 11. have a finger in the pie. Since the reflection loop is repeated infinitely, it becomes a multiple interference structure. Furthermore, the reason why the inclination angle of each reflection grating is set to 45 degrees with respect to the propagation direction is that the reflected wave amplitude does not decrease, the reflection efficiency is good, and the effect of multiple interference is large. Also, since the angle of incidence of the surface acoustic wave on the reflection grating can be said to be 45°, the angle of reflection is 90°. The reflection gratings 12 and 15 are provided on a propagation path of surface acoustic waves connecting the transmitting converter 10 and the receiving converter.
第３図の模式図により、第２図の実施例の作動
原理を説明する。 The operating principle of the embodiment of FIG. 2 will be explained with reference to the schematic diagram of FIG. 3.
第３図において、１６は送波変換器、１７は受
波変換器、１８，１９，２０，２１は反射格子で
ありａ，ｂ，ｃ，ｄの伝搬路を有する反射ループ
を作成する。伝搬路ａ，ｂ，ｃ，ｄの距離をＬと
し、弾性表面波の伝搬速度をＶとし、送波変換器
から送波される弾性表面波信号をS1（ｔ）、受波
変換器へ入射する弾性表面波信号をS2（ｔ）とす
ると、
S2（ｔ）＝KS1（ｔ−τ）
＋ｋδS1（ｔ−τ−Ｌ／Ｖ）＋……
＋……＋ＫδnS1（ｔ−τ−ｎＬ／Ｖ）＋ ……
となる。ここでｋ・τは定数、δは反射ループを
１回通過した時の減衰率、ｎ＝１，２，３…。さ
らに反射格子の反射率が大で減衰率δが１に近い
時S2（ｔ）のフーリエ変換S2（ｆ）は
S2（ｆ）
＝KS1（ｆ）δ｛−（０±ｍＶ／Ｌ）｝ ……
となる。ここでＫは定数、δはデルタ関数、０
は中心周波数、ｍ＝１，２，３……
従つて、第１図に示す弾性表面波フイルターの
伝達関数は第４図の如くなる。 In FIG. 3, 16 is a transmitting converter, 17 is a receiving converter, and 18, 19, 20, and 21 are reflection gratings, which create a reflection loop having propagation paths a, b, c, and d. The distances of the propagation paths a, b, c, and d are L, the propagation speed of the surface acoustic wave is V, and the surface acoustic wave signal transmitted from the transmitting converter is S 1 (t) to the receiving converter. If the incident surface acoustic wave signal is S 2 (t), then S 2 (t)=KS 1 (t-τ) +kδS 1 (t-τ-L/V)+... +...+Kδ n S 1 ( t-τ-nL/V)+... Here, k·τ is a constant, δ is the attenuation rate when passing through the reflection loop once, and n=1, 2, 3, etc. Furthermore, when the reflectance of the reflection grating is large and the attenuation factor δ is close to 1, the Fourier transform S 2 (f) of S 2 (t) is S 2 (f) = KS 1 (f) δ{−( 0 ±mV/ L)} …… becomes. Here K is a constant, δ is a delta function, 0
is the center frequency, m=1, 2, 3... Therefore, the transfer function of the surface acoustic wave filter shown in FIG. 1 is as shown in FIG. 4.
第５図は送波変換器、受波変換器を構成する交
叉指電極に重みづけを施し、反射格子の反射器を
蝕刻で形成した本発明による弾性表面波フイルタ
ーの特性例を示す。Ｔは伝達関数である。 FIG. 5 shows an example of the characteristics of a surface acoustic wave filter according to the present invention in which the interdigitated electrodes constituting the transmitter and receiver converter are weighted and the reflector of the reflection grating is formed by etching. T is a transfer function.
第５図は複数の狭帯域パスバンドや形成される
ことを示しているが、式より各パスバンド間の
中心周波数はＶ／Ｌ＝０／ｍだけ離れており、Ｖに対
す
る適当なＬを選択することにより、各狭帯域パス
バンド間隔が得られた。 Figure 5 shows that multiple narrow band passbands are formed, but from the formula, the center frequencies between each passband are separated by V/L = 0 /m, and an appropriate L for V is selected. By doing so, each narrow band passband spacing was obtained.
本発明により、単一の素子を用いることにより
複数の狭帯域パスバンドを有するフイルターが得
られ、構成の簡易な低コストの通信器が実現する
もである。 According to the present invention, a filter having a plurality of narrow passbands can be obtained by using a single element, and a low-cost communication device with a simple configuration can be realized.
第６図に本発明による弾性表面波フイルターの
他の実施例の模式図を示す。 FIG. 6 shows a schematic diagram of another embodiment of the surface acoustic wave filter according to the present invention.
第６図において、２２は送波変換器、２３は受
波変換器、２４，２５，２６，２７，２８，２９
は反射格子である。送波変換器２２により送波さ
れた弾性表面波が反射格子２４へ入射した後の伝
搬経路としては、
Ａ
BCD，＝Ａ＋Ｌ
AEFGA，＝Ａ＋2L
BCDEFGA，＝Ａ＋3L
AEFGAEFGA，＝Ａ＋4L
等となり、各反射格子間の距離を適宜設定するこ
とにより、第２図の例に比し、各狭帯域パスバン
ドの帯域巾をさらに低減できる。 In FIG. 6, 22 is a transmitting converter, 23 is a receiving converter, 24, 25, 26, 27, 28, 29
is a reflection grating. The propagation path after the surface acoustic wave transmitted by the transmitting converter 22 enters the reflection grating 24 is A BCD, = A + L AEFGA, = A + 2L BCDEFGA, = A + 3L AEFGAEFGA, = A + 4L, etc., and each reflection grating By appropriately setting the distance between them, the bandwidth of each narrow passband can be further reduced compared to the example shown in FIG.
第１図は複数周波数発生器のブロツク図を示
す。第２図は本発明の実施例を示す。第３図は第
２図の作動原理を示す。第４図は伝達関数を示
す。第５図は本発明による特性例を示す。第６図
は本発明による他の実施例の模式図を示す。
１……発振回路、２……分周回路、３……混合
回路、４……低域漏波器、５……電圧制御発振回
路、６……周波数逓倍回路、７……分周回路、８
……増巾器、９……基本、１０……送波変換器、
１１……受波変換器、１２……反射格子、１３…
…反射格子、１４……反射格子、１５……反射格
子、１６……送波変換器、１７……受波変換器、
１８……反射格子、１９……反射格子、２０……
反射格子、２１……反射格子、２２……送波変換
器、２３……受波変換器、２４……反射格子、２
５……反射格子、２６……反射格子、２７……反
射格子、２８……反射格子、２９……反射格子。
FIG. 1 shows a block diagram of a multiple frequency generator. FIG. 2 shows an embodiment of the invention. FIG. 3 shows the operating principle of FIG. Figure 4 shows the transfer function. FIG. 5 shows an example of characteristics according to the present invention. FIG. 6 shows a schematic diagram of another embodiment according to the invention. 1... Oscillation circuit, 2... Frequency dividing circuit, 3... Mixing circuit, 4... Low frequency leaker, 5... Voltage controlled oscillation circuit, 6... Frequency multiplier circuit, 7... Frequency dividing circuit, 8
...Amplifier, 9...Basic, 10...Transmission converter,
11... Receiving converter, 12... Reflection grating, 13...
...reflection grating, 14...reflection grating, 15...reflection grating, 16...transmission converter, 17...reception converter,
18...Reflection grating, 19...Reflection grating, 20...
Reflection grating, 21... Reflection grating, 22... Transmission converter, 23... Receiving converter, 24... Reflection grating, 2
5...Reflection grating, 26...Reflection grating, 27...Reflection grating, 28...Reflection grating, 29...Reflection grating.
Claims (1)
換器１１を対向させて設けた圧電体９と、前記送
波変換器１０と前記受波変換器１１とを結ぶ前記
弾性表面波の伝搬路上に配置され前記弾性表面波
を90゜の反射角で反射するように伝搬路に対し45
゜傾けた第１反射格子１２と、前記第１反射格子
１２から反射した弾性表面波を再び前記送波変換
器１０と前記受波変換器１１とを結ぶ伝搬路上に
戻すよう各々弾性表面波の伝搬路に対して45゜傾
けて配置される複数の第２反射格子１３，１４
と、前記送波変換器１０と前記受波変換器１１と
を結ぶ前記弾性表面波の伝搬路上に配置され、前
記第２反射格子１３，１４により反射された弾性
表面波を前記受波変換器１１方向に90゜に反射す
る第３反射格子１５とからなり、前記第１反射格
子１２と前記複数の第２反射格子１３，１４と前
記第３反射格子１５とで前記弾性表面波の伝搬路
上に反射ループを構成したことを特徴とする弾性
表面波フイルター。1. A piezoelectric body 9 having a surface acoustic wave transmitting transducer 10 and a receiving transducer 11 disposed facing each other on its surface, and a piezoelectric body 9 having a surface acoustic wave transmitting converter 10 and a receiving transducer 11 arranged facing each other, and a piezoelectric body 9 that connects the transmitting transducer 10 and the receiving converter 11. 45° to the propagation path so as to reflect the surface acoustic waves at a reflection angle of 90°.
The first reflection grating 12 tilted at an angle of 12 degrees and the surface acoustic waves reflected from the first reflection grating 12 are adjusted so that the surface acoustic waves are returned to the propagation path connecting the transmitting converter 10 and the receiving converter 11. A plurality of second reflection gratings 13 and 14 arranged at an angle of 45 degrees with respect to the propagation path.
is arranged on the propagation path of the surface acoustic wave connecting the transmitting converter 10 and the receiving converter 11, and transmits the surface acoustic waves reflected by the second reflection gratings 13 and 14 to the receiving converter. The first reflection grating 12, the plurality of second reflection gratings 13, 14, and the third reflection grating 15 reflect on the propagation path of the surface acoustic wave. A surface acoustic wave filter comprising a reflection loop.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11713878A JPS5544253A (en) | 1978-09-22 | 1978-09-22 | Surface acoustic wave filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11713878A JPS5544253A (en) | 1978-09-22 | 1978-09-22 | Surface acoustic wave filter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5544253A JPS5544253A (en) | 1980-03-28 |
| JPS622725B2 true JPS622725B2 (en) | 1987-01-21 |
Family
ID=14704387
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11713878A Granted JPS5544253A (en) | 1978-09-22 | 1978-09-22 | Surface acoustic wave filter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5544253A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02279863A (en) * | 1989-04-19 | 1990-11-15 | Daido Steel Sheet Corp | Heat insulating panel and joining structure thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2290786A1 (en) * | 1974-11-08 | 1976-06-04 | Thomson Csf | SURFACE ELASTIC WAVE SELECTIVE REFLECTION DEVICE |
-
1978
- 1978-09-22 JP JP11713878A patent/JPS5544253A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02279863A (en) * | 1989-04-19 | 1990-11-15 | Daido Steel Sheet Corp | Heat insulating panel and joining structure thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5544253A (en) | 1980-03-28 |
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