US4320401A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Broadband microstrip antenna with automatically progressively shortened resonant dimensions with respect to increasing frequency of operation
Assignee: BAE Systems Space & Mission Systems Inc
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Filing: 1980-02-15
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Granted: 1982-03-16
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Expires: 2000-02-15
Abstract
Abstract Variable impedance devices (e.g., series resonant circuits and/or transmission line tuning stubs) are connected to predetermined locations on a microstrip radiator patch for effectively changing the effective resonant dimensions of the antenna as a function of frequency and thereby permitting effective operation over a broad range of frequencies.
Inventors
- 👤 Frank J. Schiavone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:29
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/0407; H01Q9/0421; H01Q5/00; H01Q5/30; H01Q5/307; H01Q5/314; H01Q5/328; H01Q9/0442
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
121 words
An improved microstrip antenna of the type which includes a resonant-dimensioned conductive radiator patch closely spaced over an underlying conductive surface and otherwise normally exhibiting a narrow VSWR bandwidth of only approximately 2-5%, said improved antenna comprising: a plurality of frequency responsive impedance means connected to the radiator patch at predetermined locations along a predetermined path to automatically and progressively change the effective resonant dimensions of the cavity defined between at least one edge of the patch, said predetermined path and the underlying surface for signals of differing frequencies thereby automatically providing efficient antenna operation over a frequency bandwidth which is substantially greater than the otherwise expected bandwidth of only approximately 2-5 percent for operation at less than a two-to-one VSWR.
Claim 2
Dependent Claim
121 words
An improved microstrip antenna of the type which includes a resonant-dimensioned conductive radiator patch closely spaced over an underlying conductive surface and otherwise normally exhibiting a narrow VSWR bandwidth of only approximately 2-5%, said improved antenna comprising: a plurality of frequency responsive impedance means connected to the radiator patch at predetermined locations along a predetermined path to automatically and progressively change the effective resonant dimensions of the cavity defined between at least one edge of the patch, said predetermined path and the underlying surface for signals of differing frequencies thereby automatically providing efficient antenna operation over a frequency bandwidth which is substantially greater than the otherwise expected bandwidth of only approximately 2-5 percent for operation at less than a two-to-one VSWR.
Claim 3
Dependent Claim
31 words
An improved antenna as in claim 1, wherein said impedance means comprises a series resonant circuit of discrete inductive and capacitive elements connected between the radiator patch and the underlying surface.
Claim 4
Dependent Claim
51 words
An improved antenna as in claim 1 wherein said impedance means comprises a transmission line having a predetermined electrical length at a predetermined frequency and a predetermined electrical termination at one end, the other end of said transmission line being electrically connected to said radiator patch at one of said locations.
Claim 5
Dependent Claim
43 words
An improved antenna as in any of claims 1, 2 or 3 wherein said plurality of impedance means are each connected to respectively corresponding spaced-apart locations on the radiator patch thereby defining first resonant dimensions for said cavity at a predetermined first frequency.
Claim 6
Dependent Claim
42 words
An improved antenna as in claim 4 comprising a further plurality of said impedance means, each being connected to respectively corresponding spaced-apart further locations on the radiator patch and thereby defining second resonant dimensions for said cavity at a predetermined second frequency.
Claim 7
Dependent Claim
53 words
An improved antenna as in claim 4 wherein: one portion of the radiator patch is electrically shorted to the underlying surface while an edge is left open-circuited to define a radiating aperture, and said spaced-apart locations substantially lie on a path parallel to said edge and spaced therefrom by a first predetermined amount.
Claim 8
Dependent Claim
76 words
An improved antenna as in claim 5 wherein: one portion of the radiator patch is electrically shorted to the underlying surface while an edge is left open-circuited to define a radiating aperture; said spaced-apart locations lie on a first path substantially parallel to said edge and spaced therefrom by a first predetermined amount; and said spaced-apart further locations lie on a second path substantially parallel to said edge and spaced therefrom by a second predetermined amount.
Claim 9
Dependent Claim
107 words
An improved antenna as in claim 7 wherein: the distance from said edge to said first path is substantially equal to one-fourth wavelength at a first high frequency where the respectively corresponding impedance means are responsive; the distance from said edge to said second path is substantially equal to one-fourth wavelength at a second medium frequency where the respectively corresponding impedance means are responsive; and the distance from said edge to said shorted portion is substantially equal to one-fourth wavelength at a third low frequency whereby the antenna is made capable of effective operation over a range of frequencies extending from said low to said high frequency.
Claim 10
Dependent Claim
17 words
An improved antenna as in claim 1 wherein said patch is substantially square or rectangular in shape.
Claim 11
Dependent Claim
15 words
An improved antenna as in claim 1 wherein said patch is substantially circular in shape.
Claim 12
Dependent Claim
97 words
A broadband microstrip antenna comprising: a resonant-dimensioned conductive radiator patch closely spaced over an underlying conductive surface; and a plurality of separate means connected to the radiator patch at respectively predetermined locations along plural predetermined paths for automatically and progressively electrically shortening the resonant dimensions of the antenna along successive ones of said paths for higher frequency electrical signals supplied to/from the radiator patch thereby automatically simultaneously providing efficient antenna operation over a frequency bandwidth which is substantially greater than the otherwise expected bandwidth of only approximately 2-5 percent for operation at less than a two-to-one VSWR.
Claim 13
Dependent Claim
97 words
A broadband microstrip antenna comprising: a resonant-dimensioned conductive radiator patch closely spaced over an underlying conductive surface; and a plurality of separate means connected to the radiator patch at respectively predetermined locations along plural predetermined paths for automatically and progressively electrically shortening the resonant dimensions of the antenna along successive ones of said paths for higher frequency electrical signals supplied to/from the radiator patch thereby automatically simultaneously providing efficient antenna operation over a frequency bandwidth which is substantially greater than the otherwise expected bandwidth of only approximately 2-5 percent for operation at less than a two-to-one VSWR.
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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) | 1985-03-15 | 1985-09-14 | 1986-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-15 | 1989-09-14 | 1990-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-15 | 1993-09-14 | 1994-03-16 | $7700.00 | Window Closed / Lapsed |