US3593218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric filter network
Assignee: Motors Liquidation Co
•
Filing: 1970-03-05
•
Granted: 1971-07-13
•
Expires: 1990-03-05
Abstract
Abstract A plurality of piezoelectric disc resonators are connected to form various filter networks each exhibiting a composite frequency response curve having the desirable selectivity characteristics of the individual frequency response curves of he several resonators. The selectivity of the composite frequency response curves is sufficient to permit the utilization of each of the filter networks as an IF filter in a conventional superheterodyne radio receiver.
Inventors
- 👤 Paul W Wood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:59
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/46; H03H9/54; H03H9/58; H03H9/581; H03H9/15; H03H9/17; H03H9/176; H03H9/542; H03H9/56; H03H9/562
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
322 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the high frequency side of the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, and a second circular electrode concentrically mounted on the other side of the disc; a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the second circular electrode of the first resonator, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode and connected with the other output terminal; and a resistor connected from between the second circular electrode of the first resonator and the first circular electrode of the second resonator to the other input terminal and the one output terminal for providing an impedance matching the input and output impedances; whereby the frequency response curve of the first resonator and the frequency response curve of the second resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 2
Dependent Claim
322 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the high frequency side of the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, and a second circular electrode concentrically mounted on the other side of the disc; a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the second circular electrode of the first resonator, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode and connected with the other output terminal; and a resistor connected from between the second circular electrode of the first resonator and the first circular electrode of the second resonator to the other input terminal and the one output terminal for providing an impedance matching the input and output impedances; whereby the frequency response curve of the first resonator and the frequency response curve of the second resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 3
Dependent Claim
311 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode; and a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the other output terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and the one output terminal, and an annular electrode concentrically mounted on the one side oF the disc enclosing the first circular electrode and connected with the annular electrode of the first resonator; whereby the frequency response curve of the first resonator and the inverse of the frequency response curve of the second resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 4
Dependent Claim
311 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode; and a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the other output terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and the one output terminal, and an annular electrode concentrically mounted on the one side oF the disc enclosing the first circular electrode and connected with the annular electrode of the first resonator; whereby the frequency response curve of the first resonator and the inverse of the frequency response curve of the second resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 5
Dependent Claim
81 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network as recited in claim 2 including an impedance connected from between the annular electrode of the first resonator and the annular electrode of the second resonator to the other input terminal and the one output terminal for smoothing out the top portion of the composite frequency response curve of the filter network.
Claim 6
Dependent Claim
439 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the high frequency side on the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, and a second circular electrode concentrically mounted on the other side of the disc; a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the second circular electrode of the first resonator, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode; a resistor connected from between the second circular electrode of the first resonator and the first circular electrode of the second resonator to the other input terminal and the one output terminal to provide an impedance matching the input and output impedances; and a third piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the third resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the other output terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and the one output terminal, and an annular electrode concentrically mounted on the one side of the disc and enclosing the first circular electrode and connected with the annular electrode of the second resonator; whereby the frequency response curve of the first resonator and the frequency response curve of the second resonator and the inverse of the frequency response curve of the third resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 7
Dependent Claim
439 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network comprising: a first piezoelectric resonator providing a frequency response curve exhibiting a resonance at a given frequency and having a relatively sharp falloff on the high frequency side on the given frequency, the first resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with one input terminal, and a second circular electrode concentrically mounted on the other side of the disc; a second piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the second resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the second circular electrode of the first resonator, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and one output terminal, and an annular electrode concentrically mounted on the one side of the disc enclosing the first circular electrode; a resistor connected from between the second circular electrode of the first resonator and the first circular electrode of the second resonator to the other input terminal and the one output terminal to provide an impedance matching the input and output impedances; and a third piezoelectric resonator providing a frequency response curve exhibiting a resonance at the given frequency and having a relatively sharp falloff on the low frequency side of the given frequency, the third resonator including a ferroelectric ceramic disc, a first circular electrode concentrically mounted on one side of the disc and connected with the other output terminal, a second circular electrode concentrically mounted on the other side of the disc and connected with the other input terminal and the one output terminal, and an annular electrode concentrically mounted on the one side of the disc and enclosing the first circular electrode and connected with the annular electrode of the second resonator; whereby the frequency response curve of the first resonator and the frequency response curve of the second resonator and the inverse of the frequency response curve of the third resonator are effectively superimposed with respect to the given frequency so as to form a composite frequency response curve for the filter network which is nominally centered about the given frequency and which exhibits a relatively sharp falloff on both the high and low frequency sides of the given frequency.
Claim 8
Dependent Claim
81 words
In an electrical system providing a low input impedance across a pair of input terminals and a low output impedance across a pair of output terminals, a filter network as recited in claim 4 iNcluding an impedance connected from between the annular electrode of the second resonator and the annular electrode of the third resonator to the other input terminal and the one output terminal for smoothing out the top portion of the composite frequency response curve for the filter network.
References Cited (Backward Citations)
US3345588A
Cited
US3495105A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-12 | 1975-01-11 | 1975-07-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-12 | 1979-01-11 | 1979-07-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-12 | 1983-01-11 | 1983-07-13 | $7700.00 | Window Closed / Lapsed |