US5914696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unbalanced antenna system
Assignee: Quarterhill Inc
•
Filing: 1997-09-11
•
Granted: 1999-06-22
•
Expires: 2017-09-11
Abstract
Abstract An antenna system (20) provides low radio frequency interference (RFI) using an unbalanced antenna (21) comprised of three eighths wavelength whip antenna element (22) and associated counterpoise (23). Antenna counterpoise (23) may be formed by an EMI shielding conductor which is isolated at the frequency of operation of antenna system (20) from EMI shielding serving as host interface ground conductor (28) using resonant structure (25). Resonant structure (25) isolates antenna counterpoise (23) from host interface ground conductor (28) thereby improving antenna efficiency, and substantially eliminating RFI effects arising from use of antenna system (20).
Inventors
- 👤 Ronald J. Vanderhelm
- 👤 Larry J. Zibrik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:27
CPC Classifications
H; H01; H01Q; H01Q1/00; H01Q1/12; H01Q1/22; H01Q1/2258; H01Q1/2275; H01Q9/00; H01Q9/04; H01Q9/30; H01Q9/32; H01Q9/38
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
194 words
An antenna system for reducing radio frequency interference, the antenna system to be used in association with a personal computer memory card, the antenna system comprising: an unbalanced antenna having an unbalanced antenna element and an antenna counterpoise coupled to the unbalanced antenna element; an antenna feed having a first conductor coupled to the unbalanced antenna and having a radio frequency ground element coupled to the antenna counterpoise; a host interface having a host interface ground element coupled to and integrally mounted with the antenna counterpoise; a resonant element which couples the host interface ground element to the unbalanced antenna, the resonant element electrically insulating the unbalanced antenna from the host interface ground element at a frequency of operation; and the resonant element is embodied within the personal computer memory card and further comprises: a capacitive element which electrically insulates the antenna counterpoise from the host interface ground element and has a net capacitive reactance value at the frequency of operation; and an inductive element which provides a low loss conductive connection between the antenna counterpoise and the host interface ground element and has a net inductive reactance value at the frequency of operation.
Claim 2
Dependent Claim
194 words
An antenna system for reducing radio frequency interference, the antenna system to be used in association with a personal computer memory card, the antenna system comprising: an unbalanced antenna having an unbalanced antenna element and an antenna counterpoise coupled to the unbalanced antenna element; an antenna feed having a first conductor coupled to the unbalanced antenna and having a radio frequency ground element coupled to the antenna counterpoise; a host interface having a host interface ground element coupled to and integrally mounted with the antenna counterpoise; a resonant element which couples the host interface ground element to the unbalanced antenna, the resonant element electrically insulating the unbalanced antenna from the host interface ground element at a frequency of operation; and the resonant element is embodied within the personal computer memory card and further comprises: a capacitive element which electrically insulates the antenna counterpoise from the host interface ground element and has a net capacitive reactance value at the frequency of operation; and an inductive element which provides a low loss conductive connection between the antenna counterpoise and the host interface ground element and has a net inductive reactance value at the frequency of operation.
Claim 3
Dependent Claim
58 words
The antenna system of claim 1 wherein the antenna counterpoise further comprises: a low loss conductive material in the form of a protective enclosure for electromagnetic interference shielding; a matching network within the protective enclosure which is coupled to the unbalanced antenna; and a low loss conductive connection between the antenna counterpoise and the radio frequency ground element.
Claim 4
Dependent Claim
58 words
The antenna system of claim 1 wherein the inductive element and capacitive element embodied in the personal computer memory card have reactance values which when the inductive element and the capacitive element combine in parallel result in a parallel resonant circuit at the frequency of operation, thereby substantially isolating the antenna counterpoise from the host interface ground element.
Claim 5
Dependent Claim
148 words
An antenna system for reducing radio frequency interference in an unbalanced antenna having an unbalanced antenna element and an antenna counterpoise, the unbalanced antenna integrally mounted on a personal computer memory card, the antenna system comprising: a host interface having a host interface ground element; an insulated gap positioned between the antenna counterpoise and the host interface ground element, the insulated gap electrically insulates the antenna counterpoise from the host interface ground element and the antenna counterpoise, host interface ground element and insulated gap form a capacitive element having a net capacitive reactance value at a frequency of operation associated with the unbalanced antenna; and an inductor coupled between the host interface ground element and the antenna counterpoise, the inductor providing a low loss conductive connection between the antenna counterpoise and the host interface ground element and has a net inductive reactance value at the frequency of operation.
Claim 6
Dependent Claim
148 words
An antenna system for reducing radio frequency interference in an unbalanced antenna having an unbalanced antenna element and an antenna counterpoise, the unbalanced antenna integrally mounted on a personal computer memory card, the antenna system comprising: a host interface having a host interface ground element; an insulated gap positioned between the antenna counterpoise and the host interface ground element, the insulated gap electrically insulates the antenna counterpoise from the host interface ground element and the antenna counterpoise, host interface ground element and insulated gap form a capacitive element having a net capacitive reactance value at a frequency of operation associated with the unbalanced antenna; and an inductor coupled between the host interface ground element and the antenna counterpoise, the inductor providing a low loss conductive connection between the antenna counterpoise and the host interface ground element and has a net inductive reactance value at the frequency of operation.
Claim 7
Dependent Claim
31 words
An antenna system as defined in claim 4, wherein the antenna counterpoise comprises a first electromagnetic interference shield and the unbalanced antenna element is mounted on the first electromagnetic interference shield.
Claim 8
Dependent Claim
20 words
An antenna system as defined in claim 5, wherein the host interface ground element comprises a second electromagnetic interference shield.
Claim 9
Dependent Claim
33 words
An antenna system as defined in claim 6, wherein the first and second electromagnetic interference shields and the insulated gap positioned between the first and second electromagnetic interference shields form the capacitive element.
Claim 10
Dependent Claim
44 words
An antenna system as defined 7, wherein the inductor and capacitive element have reactance values which result in a parallel resonant circuit at the frequency of operation associated with the unbalanced antenna which substantially isolates the antenna counterpoise from the host interface ground element.
Claim 11
Dependent Claim
44 words
An antenna system as defined 7, wherein the inductor and capacitive element have reactance values which result in a parallel resonant circuit at the frequency of operation associated with the unbalanced antenna which substantially isolates the antenna counterpoise from the host interface ground element.
Claim 12
Dependent Claim
19 words
An antenna system as defined in claim 4, wherein the insulated gap is formed using a multilayer board assembly.
Claim 13
Dependent Claim
28 words
An antenna system as defined in claim 7, wherein the capacitive element and inductor are coupled in parallel between the host interface ground element and the antenna counterpoise.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-06-21 | 2002-12-21 | 2003-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-06-21 | 2006-12-21 | 2007-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-06-21 | 2010-12-21 | 2011-06-22 | $7700.00 | Window Closed / Lapsed |