US3624564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric ceramic band-pass filter
Assignee: Panasonic Holdings Corp
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Filing: 1970-01-20
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Granted: 1971-11-30
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Expires: 1990-01-20
Abstract
Abstract A band-pass wave filter comprising of a first piezoelectric ceramic resonator which is provided with a pair of first input electrodes and a pair of first output electrodes, and which has a resonant mode of vibration at a predetermined frequency, a second piezoelectric ceramic resonator which is provided with a pair of second input electrodes and a pair of second output electrodes, and which has a resonant mode of vibration at a said predetermined frequency, a first shunt inductance combined in parallel with said pair of first input electrodes, a second shunt inductance connected between said pair of first output electrodes and said pair of second input electrodes, and a third shunt inductance which is connected in parallel with said pair of second output electrodes and which is opposite in the polarity to said pair of second input electrodes.
Inventors
- 👤 Yukihiko Ise
- 👤 Yuichi Kaname
- 👤 Kingo Wada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:47
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/542; H03H9/56; H03H9/562; H03H9/58; H03H9/581
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
A band-pass wave filter comprising a first piezoelectric ceramic resonator which is provided with a pair of first input electrodes and a pair of first output electrodes, and which has a resonant mode of vibration at a predetermined frequency; a second piezoelectric ceramic resonator which is provided with a pair of second input electrodes and a pair of second output electrodes, and which has a resonant mode of vibration at a said predetermined frequency; a first shunt inductance combined in parallel with said pair of first input electrodes; a second shunt inductance being in a shunt between said pair of first output electrodes and said pair of second input electrodes; and a third shunt inductance which is connected in parallel with said pair of second output electrodes and which is opposite in the polArity to said pair of second input electrodes; said first shunt inductance tuning with a capacitance between said pair of first input electrodes; said second shunt inductance tuning with a combination of a capacitance between said pair of first output electrodes and a capacitance between said pair of second input electrodes; and said third inductance tuning with a capacitance between said pair of second output electrodes.
Claim 2
Dependent Claim
199 words
A band-pass wave filter comprising a first piezoelectric ceramic resonator which is provided with a pair of first input electrodes and a pair of first output electrodes, and which has a resonant mode of vibration at a predetermined frequency; a second piezoelectric ceramic resonator which is provided with a pair of second input electrodes and a pair of second output electrodes, and which has a resonant mode of vibration at a said predetermined frequency; a first shunt inductance combined in parallel with said pair of first input electrodes; a second shunt inductance being in a shunt between said pair of first output electrodes and said pair of second input electrodes; and a third shunt inductance which is connected in parallel with said pair of second output electrodes and which is opposite in the polArity to said pair of second input electrodes; said first shunt inductance tuning with a capacitance between said pair of first input electrodes; said second shunt inductance tuning with a combination of a capacitance between said pair of first output electrodes and a capacitance between said pair of second input electrodes; and said third inductance tuning with a capacitance between said pair of second output electrodes.
Claim 3
Dependent Claim
152 words
A band-pass wave filter according to claim 1 wherein one of said two resonators have an input electrode and an output electrode positioned on one major surface thereof and two common electrodes positioned on another major surface thereof, and the other of said two resonators has an input electrode and a common electrode positioned on one major surface thereof and a common electrode and an output electrode positioned on another major surface thereof, whereby said input electrode at said one major surface is faced to said common electrode at said another major surface through a ceramic body of said resonator, said piezoelectric ceramic resonators being a thin rectangular plate and having a longitudinal resonant mode of vibration, all of said electrodes being extended on opposite major surfaces in parallel with the longitudinal axis of said resonator and being positioned symmetrically against said longitudinal axis, and all of said common electrodes being grounded.
Claim 4
Dependent Claim
152 words
A band-pass wave filter according to claim 2 wherein said one piezoelectric ceramic resonator has the following relation in connection with capacitance thereof: where Cs is a coupling capacitance between said input and output electrodes; Co is a shunt capacitance between said input electrode and said common electrode; Fr and Fa are resonant and antiresonant frequencies of said resonator, respectively; F Infinity 1 is a predetermined frequency of a pole of attenuation with reference to a transmission characteristic of said resonator; and said another resonator has the following relation in connection with capacitance thereof: where Cs'' is a coupling capacitance between said input and output electrodes; Co'' is a shunt capacitance between said input electrode and said common electrode; Fr'' and Fa'' are resonant and antiresonant frequencies of said resonator, respectively; F Infinity '' is a predetermined frequency of a pole of attenuation with reference to a transmission characteristic of said resonator.
Claim 5
Dependent Claim
122 words
A band-pass wave filter according to claim 3 wherein said first inductance has a value approximately equal to (1/(2 pi Fr)2C01 where Fr is a resonant frequency of said first resonator, and C01 is a shunt capacitance between said pair of first input electrodes; said second inductance has a value approximately equal to 1/(2 pi Fr)2 (C02 +C01'') where C02 is a shunt capacitance between said pair of first output electrodes, and C 01'' is a shunt capacitance between said pair of second input electrodes; said third shunt inductance has a value approximately equal to 1/(2 pi Fr'')2 C02'' where Fr'' is a resonant frequency of said second resonator, and C02'' is a shunt capacitance between said pair of second output electrodes.
Claim 6
Dependent Claim
38 words
A band-pass wave filter according to claim 1 wherein each of said first and second piezoelectric resonators is a thin rectangular plate having a width/length ratio selected from the group consisting of 0.14, 0.18, 0.22, 0.27 and 0.36.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |