US4001696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic antenna
Assignee: Individual
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Filing: 1974-08-02
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Granted: 1977-01-04
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Expires: 1994-08-02
Abstract
Abstract An electronic antenna adapted for concealment in an automobile or similar vehicle is tuned by the RF tuning circuits of a conventional radio receiver. In the preferred embodiment, the antenna is designed for the AM and FM broadcast bands and includes a concealed metal plate which may be suitably mounted at a convenient location on the vehicle such as being embedded in the crash panel. RF signals are received by the metal plate pick-up which is connected to both low frequency and high frequency RF amplifiers which amplify them and, after suitable filtering, provide a highly selective output to the conventional radio receiver. This is due to the fact that when the conventional radio receiver is tuned to a station, it presents a very high impedance load at that frequency thereby causing the low frequency or high frequency RF amplifier of the electronic antenna to amplify that frequency in preference to all others.
Inventors
- 👤 George Louis Bannerman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:59
CPC Classifications
H; H01; H01Q; H01Q23/00; H04; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/18
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
361 words
An electronic antenna adapted to be used with the conventional radio receiver having at least one tunable RF circuit, said antenna being tuned by said tunable RF circuit, and comprising: a concealable electromagnetic pick-up, an input transformer having primary and secondary windings, said pick-up being connected to said primary winding of said input transformer, and broad band RF pre-amplifier means having an input coupled to said secondary winding of said input transformer and an output coupled to said tunable RF circuit in said conventional radio receiver as a load for selectively amplifying only the frequencies to which said tunable RF circuit is tuned, said conventional radio receiver being tunable over at least two different broadcast bands and including a separate tunable RF circuit for each broadcast band, said broad band RF pre-amplifier means comprising: first pre-amplifier means directly connected to said secondary winding of said input transformer for amplifying signals in a first of said broadcast bands, a first tuned circuit connected between the output of said first pre-amplifier means and the tunable RF circuit for the first broadcast band in said conventional radio receiver, second pre-amplifier means coupled to said secondary winding of said input transformer for amplifying signals in a second of said broadcast bands, and a second tuned circuit connected between the output of said second pre-amplifier means and the tunable RF circuit for the second broadcast band in said conventional radio receiver, and said at least two broadcast bands being the AM and FM broadcast bands, respectively, and said first preamplifier means comprises: a first transistor having a base, a collector and an emitter, said base being directly connected to said secondary winding of said input transformer, said first transistor being connected as a grounded collector stage, a second transistor having a base, a collector, and an emitter, said second transistor being connected as a common emitter stage, a high impedance coupling circuit including an inductor and a capacitor connected in series between the emitter of said first transistor and the base of said second transistor, and a high-pass filter connected in the emitter circuit of said second transistor to attenuate frequencies below said AM broadcast band.
Claim 2
Dependent Claim
361 words
An electronic antenna adapted to be used with the conventional radio receiver having at least one tunable RF circuit, said antenna being tuned by said tunable RF circuit, and comprising: a concealable electromagnetic pick-up, an input transformer having primary and secondary windings, said pick-up being connected to said primary winding of said input transformer, and broad band RF pre-amplifier means having an input coupled to said secondary winding of said input transformer and an output coupled to said tunable RF circuit in said conventional radio receiver as a load for selectively amplifying only the frequencies to which said tunable RF circuit is tuned, said conventional radio receiver being tunable over at least two different broadcast bands and including a separate tunable RF circuit for each broadcast band, said broad band RF pre-amplifier means comprising: first pre-amplifier means directly connected to said secondary winding of said input transformer for amplifying signals in a first of said broadcast bands, a first tuned circuit connected between the output of said first pre-amplifier means and the tunable RF circuit for the first broadcast band in said conventional radio receiver, second pre-amplifier means coupled to said secondary winding of said input transformer for amplifying signals in a second of said broadcast bands, and a second tuned circuit connected between the output of said second pre-amplifier means and the tunable RF circuit for the second broadcast band in said conventional radio receiver, and said at least two broadcast bands being the AM and FM broadcast bands, respectively, and said first preamplifier means comprises: a first transistor having a base, a collector and an emitter, said base being directly connected to said secondary winding of said input transformer, said first transistor being connected as a grounded collector stage, a second transistor having a base, a collector, and an emitter, said second transistor being connected as a common emitter stage, a high impedance coupling circuit including an inductor and a capacitor connected in series between the emitter of said first transistor and the base of said second transistor, and a high-pass filter connected in the emitter circuit of said second transistor to attenuate frequencies below said AM broadcast band.
Claim 3
Dependent Claim
108 words
An electronic antenna as recited in claim 1 wherein said second pre-amplifier means comprises: a second double-tuned transformer tuned to said FM broadcast band, said second transformer having primary and secondary windings, said primary winding of said second transformer being coupled to said secondary winding of said first transformer, a third transistor having a base, a collector and an emitter, said base of said third transistor being coupled to said secondary winding of said second transformer, said third transistor being connected as a common emitter stage, and a low frequency attenuator connected in the emitter circuit of said third transistor to attentuate frequencies below said FM broadcast band.
Claim 4
Dependent Claim
45 words
An electronic antenna as recited in claim 2 wherein said first and second transformers are printed circuit transformers, comprising a printed circuit substrate having first and second planes, said primary and secondary windings being printed on said first and second planes opposite to one another.
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) | 1980-01-04 | 1980-07-05 | 1981-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-04 | 1984-07-05 | 1985-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-04 | 1988-07-05 | 1989-01-04 | $7700.00 | Window Closed / Lapsed |