US3796970A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Orthogonal resonant filter for planar transmission lines
Assignee: AT&T Inc
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Filing: 1973-04-04
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Granted: 1974-03-12
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Expires: 1993-04-04
Abstract
Abstract The conductor pattern on a dielectric substrate includes a rectangular element of finite thickness whose two surface dimensions are chosen so that each is one-half the wavelength of a desired frequency. Accordingly, the element will support two resonant orthogonal standing waves and external coupling to each wave may be provided independently. Common coupling to both waves may also be provided so that the dual resonant structure may be used as a three-port device for frequency combining and separating and is particularly well-suited for frequency conversion applications. A two-port arrangement permits generation of specific filter characteristics.
Inventors
- 👤 W Snell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:52
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/213; H01P1/2135
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
203 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a resonant filter operative in a selected frequency band, said filter being included in said conductive pattern and comprising: a rectangular element of conductive material having a first pair of opposite edges being dimensioned equal to one-half the wavelength of a first selected frequency and the other pair of opposite edges adjacent the first edge being dimensioned equal to one-half the wavelength of a second selected frequency, both said first and second frequencies being within said frequency band, said element being capable of supporting two orthogonal resonant standing waves, the first wave producing a first resonant mode between the two edges of the other pair of edges, the second wave producing a second resonant mode orthogonal to the first and between the two edges of the first pair of edges, at least three ports, means for exclusively coupling energy between the first port and the first resonant mode, means for exclusively coupling energy between the second port and the second resonant mode, and means for simultaneously couplinG energy between the third port and the orthogonal first and second resonant modes.
Claim 2
Dependent Claim
203 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a resonant filter operative in a selected frequency band, said filter being included in said conductive pattern and comprising: a rectangular element of conductive material having a first pair of opposite edges being dimensioned equal to one-half the wavelength of a first selected frequency and the other pair of opposite edges adjacent the first edge being dimensioned equal to one-half the wavelength of a second selected frequency, both said first and second frequencies being within said frequency band, said element being capable of supporting two orthogonal resonant standing waves, the first wave producing a first resonant mode between the two edges of the other pair of edges, the second wave producing a second resonant mode orthogonal to the first and between the two edges of the first pair of edges, at least three ports, means for exclusively coupling energy between the first port and the first resonant mode, means for exclusively coupling energy between the second port and the second resonant mode, and means for simultaneously couplinG energy between the third port and the orthogonal first and second resonant modes.
Claim 3
Dependent Claim
54 words
A resonant filter as claimed in claim 1 wherein each means for coupling energy between a port and a resonant mode includes a conductor lead, an edge of the lead being positioned parallel to an edge of the element and spaced apart therefrom so that capacitive coupling exists between the lead and the element.
Claim 4
Dependent Claim
36 words
A resonant filter as claimed in claim 2 wherein the spacing between the edge of the lead and the edge of the element is selected to establish the Q of the resonance coupled via said lead.
Claim 5
Dependent Claim
41 words
A resonant filter as claimed in claim 2 wherein at least one of the leads has its side positioned parallel to and spaced apart from the edge of the element so that inductive coupling exists between the lead and the element.
Claim 6
Dependent Claim
50 words
A resonant filter as claimed in claim 1 wherein said means for exclusively coupling energy between the first port and the first mode includes a first conductor lead being positioned symmetrically with respect to the centerline perpendicularly bisecting the electrical length of one edge of the other pair of edges.
Claim 7
Dependent Claim
51 words
A resonant filter as claimed in claim 5 wherein said means for exclusively coupling energy between the second port and the second resonant mode includes a second conductor lead being positioned symmetrically with respect to the centerline perpendicularly bisecting the electrical length of one edge of the first pair of edges.
Claim 8
Dependent Claim
50 words
A resonant filter as claimed in claim 1 wherein said means for simultaneously coupling energy between the third port and the orthogonal first and second resonant modes includes a common conductor lead being positioned at a first corner of the element to couple substantially equally to both orthogonal resonating modes.
Claim 9
Dependent Claim
79 words
A resonant filter as claimed in claim 7 wherein said means for simultaneously coupling energy between the third port and the orthogonal first and second resonating modes further includes an auxiliary conductor lead being positioned at a second corner of the element adjacent the first corner to couple substantially equally to both orthogonal modes, the energy of one of said modes being shifted in phase by 180 degrees from the energy of that mode coupled at the first corner.
Claim 10
Dependent Claim
139 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a frequency converter circuit included in said conductive pattern and comprising: a rectangular element of conductive material being dimensioned to support two orthogonal resonant modes at two selected frequencies, at least three ports, means for exclusively coupling a pump signal at the first port to resonate in a first mode within the element, means for exclusively coupling energy between the second port and a second resonant mode orthogonal to the first mode within the element, means for simultaneously coupling energy between a common point and both orthogonal modes, and mixing means connected to the common point and to the third port for interacting the pump signal and another signal applied thereto to produce a third signal.
Claim 11
Dependent Claim
139 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a frequency converter circuit included in said conductive pattern and comprising: a rectangular element of conductive material being dimensioned to support two orthogonal resonant modes at two selected frequencies, at least three ports, means for exclusively coupling a pump signal at the first port to resonate in a first mode within the element, means for exclusively coupling energy between the second port and a second resonant mode orthogonal to the first mode within the element, means for simultaneously coupling energy between a common point and both orthogonal modes, and mixing means connected to the common point and to the third port for interacting the pump signal and another signal applied thereto to produce a third signal.
Claim 12
Dependent Claim
70 words
A frequency converter circuit as claimed in claim 9 wherein an RF signal is applied via the second port to the element and both the pump signal and the input RF signal are coupled from the element at the common point, and wherein said mixing means is a Schottky Barrier Diode which heterodynes the pump signal and the input RF signal to produce an IF output at the third port.
Claim 13
Dependent Claim
63 words
A frequency converter circuit as claimed in claim 9 wherein an input IF signal is applied to the mixing means via the third port, and the pump signal is coupled from the element at the common point, and wherein said mixing means is a varactor diode which parametrically amplifies the input IF signal to produce an RF output signal at the common point.
Claim 14
Dependent Claim
86 words
In a planar transmission circuit having a ground plane, a substrate, and A conductive pattern on the substrate parallel to the ground plane, a resonant filter included in said conductive pattern, and comprising: a rectangular element of conductive material being dimensioned to support two orthogonal resonant modes at a first and second frequency, respectively, means for coupling energy from external the element to excite the two orthogonal resonant modes, and common means for simultaneously coupling energy from both the excited orthogonal modes to external the element.
Claim 15
Dependent Claim
86 words
In a planar transmission circuit having a ground plane, a substrate, and A conductive pattern on the substrate parallel to the ground plane, a resonant filter included in said conductive pattern, and comprising: a rectangular element of conductive material being dimensioned to support two orthogonal resonant modes at a first and second frequency, respectively, means for coupling energy from external the element to excite the two orthogonal resonant modes, and common means for simultaneously coupling energy from both the excited orthogonal modes to external the element.
Claim 16
Dependent Claim
68 words
A resonant filter as claimed in claim 12, wherein said filter has a first and second port, and wherein said means for coupling energy from external the element is a single input conductor lead located at one corner of the element and wherein said common means for simultaneously coupling energy from both the excited orthogonal modes is an output conductor lead located at another corner of the element.
Claim 17
Dependent Claim
62 words
A resonant filter as claimed in claim 13 wherein the element is nearly square, the locations of the input and output leads being selected so that energy of each of said resonant modes couples to the output conductor lead with constructive addition to produce a doubly-tuned frequency response with the center frequency of the response located between the first and second frequencies.
Claim 18
Dependent Claim
46 words
A resonant filter as claimed in claim 13 wherein the element is nearly square, the location of said leads being selected so that the energy of each of the resonant modes couples to the output conductor lead with destructive interference to produce a notch frequency response.
Claim 19
Dependent Claim
184 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a resonant filter operative in a selected frequency band, said filter being included in said conductive pattern and comprising: a rectangular element of conductive material having a first pair of opposite edges being dimensioned equal to one-half the wavelength of a first selected frequency, and means for coupling energy into the element to excite a resonant standing wave at the first frequency, characterized in that the other pair of opposite edges of the element adjacent the first edges are dimensioned equal to one-half the wavelength of a second selected frequency, both said first and second frequencies being in said selected frequency band, said element is capable of supporting two orthogonal resonant standing waves at the first and second frequencies, said means for coupling energy includes at least one conductor lead and is capable of exciting the two orthogonal resonating waves, and said filter further includes means for simultaneously coupling energy from both the excited resonant orthogonal waves to external the element.
Claim 20
Dependent Claim
184 words
In a planar transmission circuit having a ground plane, a substrate, and a conductive pattern on the substrate parallel to the ground plane, a resonant filter operative in a selected frequency band, said filter being included in said conductive pattern and comprising: a rectangular element of conductive material having a first pair of opposite edges being dimensioned equal to one-half the wavelength of a first selected frequency, and means for coupling energy into the element to excite a resonant standing wave at the first frequency, characterized in that the other pair of opposite edges of the element adjacent the first edges are dimensioned equal to one-half the wavelength of a second selected frequency, both said first and second frequencies being in said selected frequency band, said element is capable of supporting two orthogonal resonant standing waves at the first and second frequencies, said means for coupling energy includes at least one conductor lead and is capable of exciting the two orthogonal resonating waves, and said filter further includes means for simultaneously coupling energy from both the excited resonant orthogonal waves to external the element.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-03-11 | 1977-09-10 | 1978-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-11 | 1981-09-10 | 1982-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-11 | 1985-09-10 | 1986-03-12 | $7700.00 | Window Closed / Lapsed |