US3710337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Miniature tv antenna
Assignee: Jfd Electronics Corp
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Filing: 1971-06-28
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Granted: 1973-01-09
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Expires: 1991-06-28
Abstract
Abstract An antenna for TV reception predominantly in the low band and high band VHF ranges having dipoles of significantly reduced physical length as compared with conventional dipoles for reception in the above mentioned VHF ranges. Inductive elements are employed as an integral part of at least one of said dipoles for improving the bandwidth and raising the Q of the dipole. The dipoles are electrically isolated from one another by suitable frequency sensitive circuits to isolate high band operation from low band operation. Lossy components are also provided as an integral part of at least one of the dipole sections for significantly enhancing power transfer between the antenna and amplifier. The inductive elements further provide good impedance matching between antenna and amplifier to further optimize power transfer therebetween. The antenna is provided with capacitive end loads for improving both current magnitude and current distribution across the dipole in both low and high band VHF operation. Separate amplifier channels are provided for low band and high band signal amplification to improve gain and reduce intermodulation and cross-modulation effects. Input filter means in at least the low band amplifier channel is designed to counterbalance the reactive impedance of the antenna across the band width of interest. The antenna is contained within a lightweight weather-proof housing of simplified design which further facilitates handling and assembly. The antenna itself is lightweight, preferably being comprised of active and parasitic elements, deposited or otherwise formed upon a thin flexible insulating substrate. The two channel amplifiers are mounted directly upon the antenna and are contained within the lightweight antenna housing.
Inventors
- 👤 R Grant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:30
CPC Classifications
H; H01; H01Q; H01Q5/00; H01Q5/40; H01Q5/48; H01Q5/49; H01Q19/00; H01Q19/28; H01Q19/30; H01Q21/00; H01Q21/30; H01Q9/00; H01Q9/04; H01Q9/16; H01Q9/28; H01Q9/285
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
257 words
An antenna for operation over a predetermined frequency range comprising: a thin, insulating substrate; a thin, flat, elongated conductive member mounted on said substrate; said member having an electrical length l1 and a radiation resistance r1; the electrical length l1 of said member being substantially shorter than the electrical length l2 of a half-wavelength dipole adapted to receive signals in the aforesaid predetermined frequency range and having a radiation resistance r2; the electrical length of said member, measured from tip-to-tip, being reduced relative to the aforesaid half-wavelength dipole until the efficiency (Eff.) of said member relative to said half-wavelength dipole is between 5 - 20 percent; a pair of antenna output terminals; conductor means coupling said output terminals to said member at first and second connecting points lying a spaced interval apart along the length of said member; said member having first and second gaps at spaced intervals along said member; first and second lumped resistor means being respectively positioned in said first and second gaps and being electrically connected to said member to form continuous electrical paths between each free end of said member and the connecting point lying closest thereto; amplifier means having an input coupled to said output terminals for amplifying signals lying within said predetermined frequency range; the ohmic value of said resistor means being selected so that the sum of the radiation resistance (r1 and r2) of said member and the resistance of said first and second lumped resistor means is substantially the same as the input resistance of said amplifier means.
Claim 2
Dependent Claim
257 words
An antenna for operation over a predetermined frequency range comprising: a thin, insulating substrate; a thin, flat, elongated conductive member mounted on said substrate; said member having an electrical length l1 and a radiation resistance r1; the electrical length l1 of said member being substantially shorter than the electrical length l2 of a half-wavelength dipole adapted to receive signals in the aforesaid predetermined frequency range and having a radiation resistance r2; the electrical length of said member, measured from tip-to-tip, being reduced relative to the aforesaid half-wavelength dipole until the efficiency (Eff.) of said member relative to said half-wavelength dipole is between 5 - 20 percent; a pair of antenna output terminals; conductor means coupling said output terminals to said member at first and second connecting points lying a spaced interval apart along the length of said member; said member having first and second gaps at spaced intervals along said member; first and second lumped resistor means being respectively positioned in said first and second gaps and being electrically connected to said member to form continuous electrical paths between each free end of said member and the connecting point lying closest thereto; amplifier means having an input coupled to said output terminals for amplifying signals lying within said predetermined frequency range; the ohmic value of said resistor means being selected so that the sum of the radiation resistance (r1 and r2) of said member and the resistance of said first and second lumped resistor means is substantially the same as the input resistance of said amplifier means.
Claim 3
Dependent Claim
25 words
The antenna of claim 1 wherein at least a portion of said member lying on opposite sides of said connecting points have an undulating pattern.
Claim 4
Dependent Claim
40 words
The antenna of claim 1 further comprising first and second capacitive end loads each being electrically coupled to opposite ends of said member; each of said end loads being comprised of a thin flat conductive member mounted upon said sheet.
Claim 5
Dependent Claim
15 words
The antenna of claim 3 wherein said capacitive end loads are substantially rectangular in shape.
Claim 6
Dependent Claim
38 words
The antenna of claim 1 wherein first and second portions of said conductive member comprises first and second spiral shaped loops, each being connected between one of said connecting points and an associated one of said resistor means.
Claim 7
Dependent Claim
83 words
The antenna of claim 1 wherein said predetermined frequency range is the VHF low band frequency range extending between 54 and 88 MHz; the reactance component of the impedance of said antenna being a function of frequency; filter means coupled between said antenna output terminals and the input of said amplifier means, the reactance component of the impedance of said filter means substantially reduces the reactance component of the antenna to reduce VSWR and optimize power transfer between the antenna and the amplifier.
Claim 8
Dependent Claim
25 words
The antenna of claim 6 wherein said filter means further comprises means for passing only those signals whose frequencies lie within said VHF low band.
Claim 9
Dependent Claim
125 words
The antenna of claim 1 further comprising a second thin flat substantially linear elongated conductive member positioned adjacent to said first mentioned elongated conductor; said second member having a gap at its center forming first and second portions thereof; conductor means electrically connected to the adjacent inner ends of said first and second portions; said second member being adapted to receive signals lying within a second predetermined frequency band whose low frequency end is greater than the high frequency end of said first mentioned frequency band; said condUctor means including frequency sensitive impedance means having a high impedance at frequencies lying within said second frequency band to decouple signals in said second frequency band received by the first mentioned member from said antenna output terminals.
Claim 10
Dependent Claim
41 words
The antenna of claim 8 further comprising first and second capacitive end loads each being electrically coupled to opposite ends of said second member; each of said end loads being comprised of a thin flat conductive member mounted upon said sheet.
Claim 11
Dependent Claim
40 words
The antenna of claim 8 further comprising second amplifier means; second filter means coupled between the antenna output terminals and the input of said second amplifier means for passing only those signals whose frequencies lie within said second frequency band.
Claim 12
Dependent Claim
56 words
The antenna of claim 10 wherein said second predetermined frequency range is the VHF high band frequency range extending between 174 and 216 MHz; third and fourth filter means respectively coupled to the outputs of said first and second amplifiers for passing only those amplified signals which respectively lie within said UHF low and high bands.
Claim 13
Dependent Claim
105 words
The antenna of claim 8 further comprising a pair of thin flat linear elongated conductive members positioned in front of said first and second conductive members and adapted to be resonant in a third frequency range whose low frequency is substantially higher than the highest frequency end of said second predetermined frequency range; an additional amplifier means; said additional amplifier means including an input filter and an output filter for passing only those signals lying within said third frequency range; the inboard ends of said pair of members being spaced apart and having means forming output terminals for coupling to said additional amplifier input filter.
Claim 14
Dependent Claim
198 words
An antenna assembly comprising: a thin insulating substrate; dipole means being mounted on said substrate; said dipole means comprising first and second dipole arms formed of thin flat elongated conductive members joined to said substrate; amplifier means being mounted on said substrate; the inboard ends of said arms being electrically coupled to the input of said amplifier means; said amplifier means being a printed circuit of substantially low profile; first and second substantially flat resilient insulating sheets being positioned on opposite sides of said substrate; a housing comprising upper and lower shallow disk-shaped cover members having similar shaped peripheries enclosing said substrate, said printed circuit and said first and second resilient sheets; means for joining the marginal edges of said cover members substantially around their entire peripheries; said lower cover member having an opening; said amplifier means having an output connector extending through said opening; fastening means securing said connector to said lower corner member supporting a plurality of mounting brackets for mounting said antenna upon a supporting face; fastening means for joining said antenna to said mounting brackets; a plurality of means provided at three points along the periphery of said housing for receiving said fastening means.
Claim 15
Dependent Claim
198 words
An antenna assembly comprising: a thin insulating substrate; dipole means being mounted on said substrate; said dipole means comprising first and second dipole arms formed of thin flat elongated conductive members joined to said substrate; amplifier means being mounted on said substrate; the inboard ends of said arms being electrically coupled to the input of said amplifier means; said amplifier means being a printed circuit of substantially low profile; first and second substantially flat resilient insulating sheets being positioned on opposite sides of said substrate; a housing comprising upper and lower shallow disk-shaped cover members having similar shaped peripheries enclosing said substrate, said printed circuit and said first and second resilient sheets; means for joining the marginal edges of said cover members substantially around their entire peripheries; said lower cover member having an opening; said amplifier means having an output connector extending through said opening; fastening means securing said connector to said lower corner member supporting a plurality of mounting brackets for mounting said antenna upon a supporting face; fastening means for joining said antenna to said mounting brackets; a plurality of means provided at three points along the periphery of said housing for receiving said fastening means.
Claim 16
Dependent Claim
26 words
The assembly of claim 13 wherein said mounting brackets are substantially Z shaped, one free end of each of said brackets being joined to said housing.
Claim 17
Dependent Claim
55 words
The antenna assembly of claim 13 wherein said cover members are molded reinforced plastic members; each of said members having a plurality of reinforcing ribs molded into their surfaces so as to form shallow depressions along the interior surfaces of said members and raised portions of low profile along the exterior surfaces of said members.
Claim 18
Dependent Claim
24 words
The antenna assembly of claim 15 wherein the reinforcing ribs of at least one of said cover members are arranged in a radial fashion.
Claim 19
Dependent Claim
34 words
The antenna assembly of claim 15 wherein the reinforcing ribs of said upper cover member Forms a V-shaped configuration wherein the apex of said V-shaped configuration identifies the front end of said antenna assembly.
Claim 20
Dependent Claim
20 words
The antenna assembly of claim 13 wherein said substrate is formed of a thin flexible substantially inelastic sheet of plastic.
References Cited (Backward Citations)
US3475759A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |