US3967276A — Antenna structures having reactance at free end

Claim 1

Independent Claim 95 words

In an antenna structure, means serving as a ground plane, a number of elongated conductors having mutual spacings which are small against operating wave length, and positioned substantially perpendicular to said ground plane; some of said conductors at their lower ends being connected to said ground plane while at least one of said conductors is connected to the input terminal of the antenna structure, inductive elements, and separate conductive segments terminating each of said elongated conductors at its upper end, to act as top capacitors against said ground plane, and interconnected by said inductive elements.

Claim 2

Dependent Claim 95 words

In an antenna structure, means serving as a ground plane, a number of elongated conductors having mutual spacings which are small against operating wave length, and positioned substantially perpendicular to said ground plane; some of said conductors at their lower ends being connected to said ground plane while at least one of said conductors is connected to the input terminal of the antenna structure, inductive elements, and separate conductive segments terminating each of said elongated conductors at its upper end, to act as top capacitors against said ground plane, and interconnected by said inductive elements.

Claim 3

Dependent Claim 28 words

Structure according to claim 1, wherein said conductors are substantially of cylindrical configuration, and said conducting segments are arranged in a plane substantially parallel to said ground plane.

Claim 4

Dependent Claim 58 words

Structure according to claim 1, wherein the inductive elements are so dimensioned that the input impedance of the antenna when compared with the input impedance of an antenna of equal dimensions but with all the elongated conductors connected to the input terminal, is increased by a factor approximately equal to the square of the number of elongated conductors.

Claim 5

Dependent Claim 69 words

Structure according to claim 1, comprising a number N of substantially equal conductors, and substantially equal top capacitors arranged symmetrically around an axis substantially perpendicular to said ground plane; the interconnecting inductances being so dimensioned that the effective height of the antenna is approximately N times the physical height, and the radiation resistance approximately N 2 times the radiation resistance of a conventional monopole antenna having the same height.

Claim 6

Dependent Claim 47 words

Structure according to claim 4, wherein at a wavelength of the order of 60 cm, an antenna having four parallel conductors has a physical height of the order of 2.67 cm, an effective height of the order of 10.7 cm and a radiation resistance of 50 Ohm.

Claim 7

Dependent Claim 32 words

Structure according to claim 4, wherein an antenna having six parallel conductors has a physical height of the order of 1.8 cm and a radiation resistance of 50 Ohm, at 500 Mhz.

Claim 8

Dependent Claim 26 words

Structure according to claim 1, comprising non-uniform conducting segments producing an auxiliary dipole moment in a direction substantially parallel to the ground plane, causing auxiliary radiation.

Claim 9

Dependent Claim 25 words

Structure according to claim 7, comprising substantially non-uniform conductors and top capacitors having two planes of symmetry to avoid formation of a horizontal dipole moment.

Claim 10

Dependent Claim 69 words

Structure according to claim 7, comprising non-uniform conductors and non-uniform conducting segments extending within a common plane parallel to said ground plane, representing the x-y plane of a Cartesian coordinate system; said elongated conductors and conducting segments being so dimensioned that the antenna is image-symmetrical with respect to the x-z plane of said system; the symmetry condition assuring the auxiliary dipole moment in the y-direction to become substantially eliminated.

Claim 11

Dependent Claim 70 words

Structure according to claim 7, comprising elongated conductors and non-uniform conducting segments extending within a common plane parallel to the ground plane and representing the x-y plane of a Cartesian coordinate system; said elongated conductors and conducting segments being so formed as to have as a symmetry plane the y-z plane of said coordinate system; said symmetry condition assuring the auxiliary dipole moment in the x-direction to become substantially eliminated.

Claim 12

Dependent Claim 55 words

Structure according to claim 8, comprising three conductors with top capacitors connected thereto, the middle segment being relatively thin and connected to the input terminal; the two other conductors being relatively thick and connected to ground; and having top capacitor plates forming together a larger surface than the top capacitor plate of the middle conductor.

Claim 13

Dependent Claim 98 words

Structure according to claim 8, comprising two pairs of antenna segments, each pair having identical conductors and top capacitors associated therewith; one pair being interconnected at the lower ends of said conductors, and connected to the input terminal; the other pair of antenna segments being connected to the ground plane; the diameter of the latter pair of conductors being substantially larger than the diameters of the former pair of conductors; and the top capacitors of the latter pair having smaller surface areas than the top capacitors of the former pair; the inductances interconnecting the segments being substantially alike.

Claim 14

Dependent Claim 64 words

Structure according to claim 1, for the high frequency range, comprising an insulating mast and elongated conductors in the form of wires supported on said mast; some of said wires beng electrically interconnected at the base of said mast, and grounded; and at least one of said wires connected to the input terminal; the top capacitors being formed by sets of radially directed wires.

Claim 15

Dependent Claim 32 words

Structure according to claim 1, for the UHF and higher ranges, comprising top capacitors and interconnecting inductances in the form of metal films deposited on a dielectric base like a printed circuit.

Claim 16

Dependent Claim 26 words

Structure according to claim 1, comprising as top capacitors, means for producing predetermined capacities from smaller capacitor elements connected to said conductors through appropriately dimensioned inductances.

Claim 17

Dependent Claim 79 words

Structure according to claim 1, comprising as top capacitors, means for producing a predetermined capacity from a number of smaller capacitor elements connected to said conductors through appropriately dimensioned inductances; one of the top capacitors being formed of a bundle of rods, and another of said top capacitors being formed of a shorter bundle of rods connected to the antenna structure through an inductance; exact equivalence between said two bundles substantially existing for a relatively limited frequency range only.

Claim 18

Dependent Claim 58 words

Structure according to claim 1, wherein the size of the top capacitors required for optimum matching of the antenna to the input terminal, power source, receiver or transmission line, connected to the antenna, is reduced by increasing the inductance of the elongated conductors, comprising means for increasing said inductance by providing conductors in the form of coaxial spirals.

Claim 19

Dependent Claim 131 words

In an antenna structure, two sets of elongated conductors, the conductors in each set having mutual spacings which are small against operating wave length, and positioned substantially parallel to each other; one set forming an image of the other set; some of the adjacent conductor ends of the different conductor sets being connected to each other, while at least one of the conductors in each conductor set is connected to an input terminal of the antenna structure; the conductors of each conductor set forming the feed lines for a balanced two-wire input line to the antenna structure, two sets of separate conductive segments terminating each set of said elongated conductors at their other ends to act as capacitors, and inductive elements interconnecting said capacitors, to provide a desired input impedance characteristic.

Claim 20

Dependent Claim 131 words

In an antenna structure, two sets of elongated conductors, the conductors in each set having mutual spacings which are small against operating wave length, and positioned substantially parallel to each other; one set forming an image of the other set; some of the adjacent conductor ends of the different conductor sets being connected to each other, while at least one of the conductors in each conductor set is connected to an input terminal of the antenna structure; the conductors of each conductor set forming the feed lines for a balanced two-wire input line to the antenna structure, two sets of separate conductive segments terminating each set of said elongated conductors at their other ends to act as capacitors, and inductive elements interconnecting said capacitors, to provide a desired input impedance characteristic.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-06-29	1979-12-29	1980-06-29	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-06-29	1983-12-29	1984-06-29	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-06-29	1987-12-29	1988-06-29	$7700.00	Window Closed / Lapsed

Antenna structures having reactance at free end

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