US4383260A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low profile electric field sensor
Assignee: Foster Airdata Systems Inc
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Filing: 1981-03-27
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Granted: 1983-05-10
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Expires: 2001-03-27
Abstract
Abstract A low profile electric field sensor is arranged to sense electric field potentials with respect to a local ground plane. The sensor includes an antenna in a generally planar format with a major dimension extending generally parallel to the local ground plane. To maintain signal to noise ratio, while at the same time minimizing the height of the antenna so as to provide a low profile, the antenna is coupled to a charge amplifier. The charge amplifier comprises an operational amplifier, preferably with a capacitor feedback between output and an inverting input, and the antenna is conductively connected to the inverting input.
Inventors
- 👤 Paul A. Ryan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:32
CPC Classifications
H; H01; H01Q; H01Q9/00; H01Q9/04; H01Q9/0407; H01Q23/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
119 words
A low profile electric field sensor adapted for use in sensing atmospheric weather disturbances by sensing an RF electric field at 1 MHz or below in relation to a local ground plane in which an output signal is produced which is relatively independent of height from said local ground plane within a given range of heights, comprising: an antenna comprised of metallic material, generally planar in form, having a major dimension generally parallel to said local ground plane, quasi-charge amplifying means responsive to charge and producing an output signal, and connecting means conductively connecting said antenna to said quasi-charge amplifying means, whereby sensor height can be freely selected within said given range without accepting a reduction in output signal.
Claim 2
Dependent Claim
119 words
A low profile electric field sensor adapted for use in sensing atmospheric weather disturbances by sensing an RF electric field at 1 MHz or below in relation to a local ground plane in which an output signal is produced which is relatively independent of height from said local ground plane within a given range of heights, comprising: an antenna comprised of metallic material, generally planar in form, having a major dimension generally parallel to said local ground plane, quasi-charge amplifying means responsive to charge and producing an output signal, and connecting means conductively connecting said antenna to said quasi-charge amplifying means, whereby sensor height can be freely selected within said given range without accepting a reduction in output signal.
Claim 3
Dependent Claim
38 words
The sensor of claim 1 wherein said quasi-charge amplifying means includes an operational amplifier, capacitive feedback means connecting an output of said amplifier to an inverting input, and wherein said connecting means is coupled to said inverting input.
Claim 4
Dependent Claim
22 words
The sensor of claims 1 or 2 in which said antenna extends no further than 3 cm. from said local ground plane.
Claim 5
Dependent Claim
28 words
The sensor of claims 1 or 2 in which said antenna has an effective height of less than or equal to 3 cm. from said local ground plane.
Claim 6
Dependent Claim
18 words
The sensor of claims 1 or 2 in which said antenna has an effective height of 2 cm.
Claim 7
Dependent Claim
81 words
A low profile electric field sensor adapted for use in sensing atmospheric weather disturbances by sensing an RF electric field at 1 MHz or below in relation to a local ground plane comprising: an antenna comprised of metallic material with generally planar form having a major dimension generally parallel to said local ground plane, and an effective height from said local ground plane of no more than 3 cm; and amplifying means including a quasi-charge amplifier conductively connected to said antenna.
Claim 8
Dependent Claim
81 words
A low profile electric field sensor adapted for use in sensing atmospheric weather disturbances by sensing an RF electric field at 1 MHz or below in relation to a local ground plane comprising: an antenna comprised of metallic material with generally planar form having a major dimension generally parallel to said local ground plane, and an effective height from said local ground plane of no more than 3 cm; and amplifying means including a quasi-charge amplifier conductively connected to said antenna.
Claim 9
Dependent Claim
19 words
The apparatus of claim 6 wherein said amplifying means includes an amplifier with feedback impedance of net capacitive reactance.
Claim 10
Dependent Claim
39 words
The apparatus of claim 6 wherein said quasi-charge amplifier comprises an operational amplifier with an inverting input and an output, capacitive feedback means coupled between said output and said inverting input, and said antenna coupled to said inverting input.
Claim 11
Dependent Claim
16 words
The sensor of claim 1 in which said quasi-charge amplifying means has a low input impedance.
Claim 12
Dependent Claim
15 words
The sensor of claim 6 or 9 which operates in the vicinity of 50 KHz.
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) | 1986-05-09 | 1986-11-08 | 1987-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-09 | 1990-11-08 | 1991-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-09 | 1994-11-08 | 1995-05-10 | $7700.00 | Window Closed / Lapsed |