GB834544A - Improvements in and relating to electrical filters - Google Patents
Improvements in and relating to electrical filtersInfo
- Publication number
- GB834544A GB834544A GB2134955A GB2134955A GB834544A GB 834544 A GB834544 A GB 834544A GB 2134955 A GB2134955 A GB 2134955A GB 2134955 A GB2134955 A GB 2134955A GB 834544 A GB834544 A GB 834544A
- Authority
- GB
- United Kingdom
- Prior art keywords
- band
- network
- crystal
- pass
- elimination
- 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
- 239000013078 crystal Substances 0.000 abstract 6
- 238000003379 elimination reaction Methods 0.000 abstract 4
- 230000008030 elimination Effects 0.000 abstract 3
- 230000005540 biological transmission Effects 0.000 abstract 1
- 230000000295 complement effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 abstract 1
- 238000005286 illumination Methods 0.000 abstract 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
- H03H9/542—Filters comprising resonators of piezoelectric or electrostrictive material including passive elements
Landscapes
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
Abstract
834,544. Band-illumination filters. BRITISH TELECOMMUNICATIONS RESEARCH Ltd. July 11, 1956 [July 22, 1955], No. 21349/55. Class 40 (8). A band-elimination filter comprises a lowpass network and a high-pass network connected in parallel, with a piezo-electric crystal arranged to produce an elimination band in one of the networks. The low-pass network 11 and high-pass network 12 are of conventional design and together provide an all-pass transmission characteristic between input terminals 13, 14 and output terminals 15, 16. The elimination band is provided by a crystal 20 in the low-pass network 11, shunt capacitance 19 being adjusted to compensate the capacitance of the crystal. The cut-off frequencies of the networks are arranged to be co-incident at a frequency such that the network 11 has a high degree of attenuation at any undesired overtone frequencies of the crystal. The Provisional Specification describes a circuit comprising a band-pass network and a complementary band-stop network connected in parallel to provide an all-pass overall characteristic in which a narrow elimination band is provided by a crystal arranged as a shunt element in the band-pass network. Such a circuit may be used to eliminate the effects of coupled resonances both below and above the fundamental resonance of the crystal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2134955A GB834544A (en) | 1955-07-22 | 1955-07-22 | Improvements in and relating to electrical filters |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB2134955A GB834544A (en) | 1955-07-22 | 1955-07-22 | Improvements in and relating to electrical filters |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB834544A true GB834544A (en) | 1960-05-11 |
Family
ID=10161391
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB2134955A Expired GB834544A (en) | 1955-07-22 | 1955-07-22 | Improvements in and relating to electrical filters |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB834544A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008145659A1 (en) * | 2007-05-29 | 2008-12-04 | Epcos Ag | Multiband filter |
-
1955
- 1955-07-22 GB GB2134955A patent/GB834544A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008145659A1 (en) * | 2007-05-29 | 2008-12-04 | Epcos Ag | Multiband filter |
| US8384496B2 (en) | 2007-05-29 | 2013-02-26 | Epcos Ag | Multiband filter |
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