US3840828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature-stable dielectric resonator filters for stripline
Assignee: AT&T Inc
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Filing: 1973-11-08
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Granted: 1974-10-08
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Expires: 1993-11-08
Abstract
Abstract There is disclosed a band-reject dielectric resonator filter for stripline, the resonators being disposed over the principal conductor and separated therefrom by a dielectric spacer and offset from the symmetry position over the stripline conductor. The offset is selected so that the magnetic field lines of the stripline pass through the planar, parallel surfaces of the resonator to a maximum degree. Large scale fabrication of the stripline is facilitated, while accurate normal positioning of the resonator is assured; and resonator to stripline coupling is relatively insensitive to small variations in the lateral position. Further, the principal conductor has no substantial degradation of the resonator Q. Strong coupling has been demonstrated with the use of low dielectric constant materials that are readily-temperature compensated. Also, disclosed are a plurality of such resonators coupled together to create specially-shaped reject bands or pass bands.
Inventors
- 👤 D Linn
- 👤 J Plourde
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:28
CPC Classifications
H; H01; H01P; H01P7/00; H01P7/10; H01P1/00; H01P1/20; H01P1/201; H01P1/203; H01P1/20309
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
116 words
A microwave circuit comprising a stripline including a planar dielectric substrate and a principal conductor deposited on one surface of said substrate, and means for filtering a portion of the frequencies of microwave radiation transmitted through said stripline, comprising a dielectric resonator having planar surfaces parallel to the plane of said substrate and having a composition selected for temperature compensation of its resonant frequencies, and a dielectric spacer between said resonator and said conductor, said resonator being offset from symmetrical alignment over said conductor and adapted to support a TE01 mode of its resonant frequencies, the degree of offset being selected to maximize the degree of coupling of said mode from said stripline to said resonator.
Claim 2
Dependent Claim
116 words
A microwave circuit comprising a stripline including a planar dielectric substrate and a principal conductor deposited on one surface of said substrate, and means for filtering a portion of the frequencies of microwave radiation transmitted through said stripline, comprising a dielectric resonator having planar surfaces parallel to the plane of said substrate and having a composition selected for temperature compensation of its resonant frequencies, and a dielectric spacer between said resonator and said conductor, said resonator being offset from symmetrical alignment over said conductor and adapted to support a TE01 mode of its resonant frequencies, the degree of offset being selected to maximize the degree of coupling of said mode from said stripline to said resonator.
Claim 3
Dependent Claim
51 words
A microwave circuit according to claim 1 in which the composition of the dielectric resonator is selected to have positive coefficient of frequency variation with respect to temperature and the substrate of the stripline and housing effects are selected to have a negative coefficient of frequency variation with respect to temperature.
Claim 4
Dependent Claim
34 words
A microwave circuit according to claim 1 in which the center-to-center offset spacing of the dielectric resonator with respect to the principal conductor is substantially less than the half width of the dielectric resonator.
Claim 5
Dependent Claim
45 words
A microwave circuit according to claim 3 including a ground plane having a metallic housing structure about the dielectric resonator, the housing structure being selected to have the opposite coefficient frequency variation with respect to temperature as compared to that possessed by the dielectric resonator.
Claim 6
Dependent Claim
18 words
A microwave circuit according to claim 4 including means for tuning the filter characteristic of the dielectric resonator.
Claim 7
Dependent Claim
51 words
A microwave circuit according to claim 1 including a plurality of the dielectric resonators disposed at least partially over the principal conductor and separated by odd multiples of a quarter wavelengths from one another to minimize spurious coupling resonances therebetween, said circuit including a metallic housing structure intruding between said resonators.
Claim 8
Dependent Claim
31 words
A microwave circuit according to claim 1 in which the dielectric spacer is composed of a readily-machinable dielectric material, whereby the spacing between two of its surfaces may be acCurately determined.
Claim 9
Dependent Claim
90 words
A microwave circuit according to claim 1 including a waveguide housing that is proportioned to be beyond cut-off for a band of frequencies to be propagated and including a plurality of dielectric resonators disposed within said housing with spacings for mutual coupling therebetween to provide propagation through the housing for the band of frequencies, the stripline comprising a planar dielectric substrate extending completely through the housing and a principal conductor that is broken in at least one region within said housing in proximity to one or more of the resonators.
Claim 10
Dependent Claim
27 words
A microwave circuit according to claim 8 in which the principal conductor is terminated under the end resonators of the plurality of resonators and is absent therebetween.
Claim 11
Dependent Claim
65 words
A microwave circuit according to claim 8 in which the plurality of dielectric resonators have spacings between adjacent resonators substantially equal to a quarterwave length for the center frequency of the band of frequencies and the principal conductor includes segments extending between adjacent resonators, so that the principal conductor lacks continuity only in a plurality of limited regions respectively adjacent to each of the resonators.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |