US5600740A
Expired / Lapsed
US
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Narrowband waveguide filter
Assignee: Zeneca Inc
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Filing: 1995-06-20
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Granted: 1997-02-04
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Expires: 2015-06-20
Abstract
Abstract The present invention is a passband-type waveguide filter in which a periodic distortion is employed which has a sinusoidal, or alternately configured, distortion, which changes phase at a point along the periodic distortion. The passband filter comprises essentially any waveguide, designed as a waveguide, with a periodic distortion added to at least one of the sides of the waveguide. The waveguide can be a rectangular cross section metallic microwave type, cylindrical, elliptical, or microstrip. The waveguide may be optical, a SAW type waveguide or any waveguide of the prior art. In a preferred embodiment a waveguide structure supports propagation of a wave along the waveguide, the waveguide structure containing a boundary and the waveguide structure containing a filter portion having a portion of said boundary with a sinusoidal distortion following: f(z)=1+A sin (k.sub.w z) for 0<=z<=L/2 f(z)=1-A sin (k.sub.w z) for L/2<=z<=L where f(z) is a distance perpendicular to the boundary, z is a distance along the wall in the direction of wave propagation, A is a dimensionless amplitude <<1, kw is the boundary wave number chosen to satisfy the Bragg condition k w =2k m , and L is the length of the filter portion waveguide.
Inventors
- 👤 Omar R. Asfar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:08
CPC Classifications
H; H01; H01P; H01P1/00; H01P1/20; H01P1/207; G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/124; G02B2006/12083; G02B2006/12107; G02B2006/12109
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
118 words
A waveguide filter comprising: a waveguide structure which supports propagation of a wave along the waveguide, said waveguide structure containing a boundary, said waveguide structure containing a filter portion having a portion of said boundary with a distortion following: f(z)=1+A F.sub.p (K.sub.w z) for 0≦z≦L/2, and f(z)=1-A F.sub.p (K.sub.w z) for L/2≦z≦L where F p (K w z) is a periodic function with period ##EQU4## f(z) is a distance perpendicular to the boundary, z is a distance along the structure in the direction of wave propagation A is a dimensionless amplitude <<1 k w is the boundary wave number chosen to satisfy the Bragg condition k w =2k m L is the length of the filter portion waveguide.
Claim 2
Dependent Claim
118 words
A waveguide filter comprising: a waveguide structure which supports propagation of a wave along the waveguide, said waveguide structure containing a boundary, said waveguide structure containing a filter portion having a portion of said boundary with a distortion following: f(z)=1+A F.sub.p (K.sub.w z) for 0≦z≦L/2, and f(z)=1-A F.sub.p (K.sub.w z) for L/2≦z≦L where F p (K w z) is a periodic function with period ##EQU4## f(z) is a distance perpendicular to the boundary, z is a distance along the structure in the direction of wave propagation A is a dimensionless amplitude <<1 k w is the boundary wave number chosen to satisfy the Bragg condition k w =2k m L is the length of the filter portion waveguide.
Claim 3
Dependent Claim
20 words
The waveguide filter of claim 1 wherein said distortion is sinusoidal and F p (K w z)=Sin K w z.
Claim 4
Dependent Claim
13 words
The waveguide filter of claim 1 wherein said distortion is rectangular and ##EQU5##
Claim 5
Dependent Claim
13 words
The waveguide filter of claim 1 wherein said distortion is triangular and ##EQU6##
Claim 6
Dependent Claim
57 words
The waveguide filter of claim 1, wherein said waveguide structure comprises a transparent slab with a reflecting top and bottom surface forming said boundary and configured to propagate light along said slab, with said distortion being formed in one of said top and bottom surfaces so as to vary the distance between said top and bottom surfaces.
Claim 7
Dependent Claim
65 words
The waveguide filter of claim 1, wherein said waveguide structure comprises a hollow or dielectric filled rectangular cross-section conductive tube configured to propagate electromagnetic waves, the inner side of said conductive tube forming said boundary and wherein said distortion is formed along at least one side of said rectangular tube so as to vary the width of said tube along said at least one side.
Claim 8
Dependent Claim
58 words
The waveguide filter of claim 1, wherein said waveguide structure comprises a hollow or dielectric filled elliptical cross-section conductive tube configured to propagate electromagnetic waves, the inner side of said conductive tube forming said boundary and wherein said distortion is formed as a variation of the major and minor radius of the inner side of said conductive tube.
Claim 9
Dependent Claim
63 words
The waveguide filter of claim 1, wherein said waveguide structure comprises a thin rectangular slab which supports a vibrational wave along said slab, said boundary being the side surfaces of said rectangular slab, and wherein said distortion is formed along at least one side of said rectangular slab so as to vary the width of said slab along said at least one side.
Claim 10
Dependent Claim
54 words
The waveguide filter of claim 1, wherein said waveguide structure comprises a conductive plane and an elongated conductive strip above said conductive plane and wherein said distortion is formed along at least one edge of said elongated conductive strip so as to vary the width of said strip along said at least one edge.
Claim 11
Independent Claim
131 words
A method of filtering a wave signal comprising: injecting an electromagnetic or vibrational wave into a waveguide having a boundary and filter portion, and receiving or detecting the portion of the wave transmitted by said waveguide wherein the said filter portion of said waveguide contains a portion which has a distortion following: f(z)=1+A F.sub.p (K.sub.w z) for 0≦z≦L/2, and f(z)=1-A F.sub.p (K.sub.w z) for L/2≦z≦L where F p (K w z) is a periodic function with period ##EQU7## f(z) is a distance perpendicular to the boundary, z is a distance along the boundary in the direction of wave propagation A is a dimensionless amplitude <<1 k w is the boundary wave number chosen to satisfy the Bragg condition k w =2k m L is the length of the filter portion waveguide.
Claim 12
Independent Claim
131 words
A method of filtering a wave signal comprising: injecting an electromagnetic or vibrational wave into a waveguide having a boundary and filter portion, and receiving or detecting the portion of the wave transmitted by said waveguide wherein the said filter portion of said waveguide contains a portion which has a distortion following: f(z)=1+A F.sub.p (K.sub.w z) for 0≦z≦L/2, and f(z)=1-A F.sub.p (K.sub.w z) for L/2≦z≦L where F p (K w z) is a periodic function with period ##EQU7## f(z) is a distance perpendicular to the boundary, z is a distance along the boundary in the direction of wave propagation A is a dimensionless amplitude <<1 k w is the boundary wave number chosen to satisfy the Bragg condition k w =2k m L is the length of the filter portion waveguide.
Claim 13
Dependent Claim
24 words
The method of filtering a wave signal of claim 10 wherein said distortion is sinusoidal and F p (K w z)=Sin K w z.
Claim 14
Dependent Claim
17 words
The method of filtering a wave signal of claim 10 wherein said distortion is rectangular and ##EQU8##
Claim 15
Dependent Claim
17 words
The method of filtering a wave signal of claim 10 wherein said distortion is triangular and ##EQU9##
Claim 16
Dependent Claim
60 words
The method of filtering a wave signal of claim 10, wherein said waveguide comprises a transparent slab with a reflecting top and bottom surface forming said boundary and configured to propagate light along said slab, with said distortion being formed in one of said top and bottom surfaces so as to vary the distance between said top and bottom surfaces.
Claim 17
Dependent Claim
70 words
The method of filtering a wave signal of claim 10, wherein said waveguide comprises a a hollow or dielectric filled rectangular cross section conductive tube configured to propagate electromagnetic waves, the inner side of said conductive tube forming said boundary and wherein said distortion is formed along at least one side of said rectangular tube so as to vary the width of said tube along said at least one side.
Claim 18
Dependent Claim
62 words
The method of filtering a wave signal of claim 10, wherein said waveguide comprises a hollow or dielectric filled elliptical cross section conductive tube configured to propagate electromagnetic waves, the inner side of said conductive tube forming said boundary and wherein said distortion is formed as a variation of the major and minor radius of the inner side of said conductive tube.
Claim 19
Dependent Claim
66 words
The method of filtering a wave signal of claim 10, wherein said waveguide comprises a thin rectangular slab which supports a vibrational wave along the slab, said boundary being the side surfaces of said rectangular slab, and wherein said distortion is formed along at least one side of said rectangular slab so as to vary the width of said slab along said at least one side.
Claim 20
Dependent Claim
57 words
The method of filtering a wave signal of claim 10, wherein said waveguide comprises a conductive plane and an elongated conductive strip above said conductive plane and wherein said distortion is formed along at least one edge of said elongated conductive strip so as to vary the width of said strip along said at least one edge.
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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) | 2000-02-04 | 2000-08-05 | 2001-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-04 | 2004-08-05 | 2005-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-04 | 2008-08-05 | 2009-02-04 | $7700.00 | Window Closed / Lapsed |