US3611397A

US3611397A - Folded dipole with end-loading elements

Info

Publication number: US3611397A
Application number: US857438A
Authority: US
Inventors: George Poliakoff
Original assignee: AERIAL ELECTRONICS CORP
Current assignee: AERIAL ELECTRONICS CORP
Priority date: 1969-09-12
Filing date: 1969-09-12
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05

Abstract

A combination Hertz and loop-type antenna which effectively receives both electromagnetic and waves of radio and TV broadcasts by virtue of oppositely extending elongated outer tubular conductors that concentrically surround an inner conductor and are held in annularly spaced relationship by conductive elements located near the ends of the conductors and insulating spacers medially thereof. The inner conductor is used to clamp onto a vertical mast by means of a clamp to thereby fix the antenna in a substantially horizontal position, and terminals are provided for connecting insulated output leads to the outer conductors adjacent their inner ends.

Description

United States Patent [72] Inventor George Poliakoif Great Neck, N.Y. [21] Appl. No. 857,438 [22] Filed Sept. 12, 1969 [45] Patented Oct. 5, 1971 [73] Assignee Aerial Electronics Corporation East Islip, NY.

[54] FOLDED DIPOLE WITH END-LOADING ELEMENTS 2 Claims, 2 Drawing Figs.

[52] US. Cl 343/792, 343/802, 343/803 [51] lnt.Cl H01g9/l6 [50] Field of Search 343/790, 791, 792, 803,908, 802

[56] References Cited UNITED STATES PATENTS 2.321.454 6/1943 Brown 343/792 2,432,858 12/1947 Brown 343/792 3,001,194 9/1961 Leppert.. 343/792 3,210,765 10/1965 Jones 343/752 FOREIGN PATENTS 898,281 7/1944 France 343/792 Primary Examiner-Eli Lieberman Attorney-Edward H. Loveman ABSTRACT: A combination Hertz and loop-type antenna which effectively receives both electromagnetic and waves of radio and TV broadcasts by virtue of oppositely extending elongated outer tubular conductors that concentrically surround an inner conductor and are held in annularly spaced relationship by conductive elements located near the ends of the conductors and insulating spacers medially thereof. The inner conductor is used to clamp onto a vertical mast by means of a clamp to thereby fix the antenna in a substantially horizontal position, and terminals are provided for connecting insulated output leads to the outer conductors adjacent their inner ends.

PATENTEUHBI 5l97| 3.611.397

INVENTOR GEORGE POLIAKOFF ATTORNEY FOLDED DIPOLE WITH END-LOADING ELEMENTS This invention relates to antennas for receiving FM AM, and TV broadcasts, and more particularly to a hybrid-type dipole-loop aerial.

When a radio wave is generated, there is produced in space an electric field as well as an electromagnetic field. Such fields are at right angles to each other and to the direction of wave propogation. Basically, there are two types of antennas in common use: (1) The Hertz, or dipole type; and (2) The loop type, used mostly in radio receivers. The dipole type of antenna is more sensitive to the electric field; while the loop type is more sensitive to electromagnetic fields. While dipole antennas, as well as loop-type aerials are well known, there presently exists a real need for antennas that can receive TV as well as FM and AM radio broadcasts with equally high efiiciency on the same antenna that is fixed to a mast.

Briefly, in accordance with the present invention, a hybrid antenna is provided which, while having the appearance of a single dipole aerial, is in reality, a combination of both dipole type and a loop type antenna. This is accomplished by the provision of an elongated inner tubular conductor that is electrically and spacially fixed by a connector located at each end thereof, to a pair of outer surrounding concentric conductive arms. The connectors hold the outer ends of each arm in spaced relationship and output leads are connected to the inner ends of each of these arms which are spacially supported by insulating spacers.

It is, therefore, a primary object of this invention to provide an antenna that combines the benefits of both a dipole and loop-type antenna and being compact, simple in construction, light in weight, consisting of few parts, and which is easy to ship, pack and assemble.

Another object is to provide a novel hybrid antenna that can be used to receive TV, FM and AM broadcasts with equal facility on the same antenna.

These and other objects and many of the attendant advantagesof this invention will be readily appreciated as the same becomes clear by reference to the following detailed description when considered in connection with the accompanying drawings, wherein FIG. 1 is a perspective view with parts broken away of a hybrid antenna of the present invention.

FIG. 2 is an enlarged cross-sectional view along line 22 of F IG. 1.

Referring now to the drawings, wherein like reference numerals designate like parts throughout, there is shown in FIG. 1 an antenna embodying the present invention which includes two oppositely extending horizontal tubular conductor arms 12 which are axially aligned with one another. Within each of the outer arms 12 is a single inner conductor 14 of relatively small diameter. The outer tubular conductors 12 are held in spaced concentric relationship to inner conductor 14 by a member 17 located adjacent each outer end of each of the arms 12 and by an insulated spacer 16 located at each inner end of the conductors 12 as clearly illustrated in FIG. 2. The spacers 16 may be fastened to either the inner conductor 14 or the outer conductor 12 or to both conductors by any conventional means. A fastener (not shown) of nonconductive material may be used to secure the spacer 16 to the inner conductor 14. It is of course obvious that insulator spacer 16 may be secured between

conductors

14 and 12 by other conventional means, i.e., adhesive, press fit, etc. The member 17 may be a pin or any other conventional element made of an electrically conductive material. A clamp, which is connected medially to the ends of conductor 14, between the arms 12 is attached to a vertical mast l8. Terminals 22, comprising rising nuts, are provided adjacent the inner ends of the outer conductors for connecting output leads 24, 24 thereto. Such leads are insulated from each other and pass through the eye of a bracket 26 which is clamped to the mast 18 below the antenna 10.

Conventional capacitor disks 28 having central holes 29 for receivin the outer conductors, and are carried by the latter in arrays of three disks each, with the disks 28 equally spaced in each array 30, and the arrays symmetrically arranged with respect to each other on the outer reaches of the outer conductors. Such arrays may be omitted without departing from the present invention, if desired.

In operation, since the central or inner conductor 14 is electrically connected, at each end via connectors 17, to the points of maximum signal voltage of the corresponding outer conductors, signal current is caused to flow through the inner conductors 14 as well as out through the leads 24 to the receiver (not shown). Consequently, the antenna 10 is neither a current nor a voltage antenna, nor is it a Hertzian, nor a loop antenna, but a combination of such types.

The outside diameter of the outer conductors l2, determines the band width, while the ratios of the diameters of the outside conductors 12, to that of the inside conductor 14 determines the impedance of the antenna 10.

Inasmuch as the antenna of the present invention responds both to electric and magnetic fields, it is as much a loop antenna as it is a folded dipole, but it is definitely not a plain dipole antenna because of the inner conductor. [f the inner conductor is left out, the performance of the device is greatly impaired, and while in one respect it may be considered a folded dipole in the sense that the ends of the inner conductor are connected to the outer conductor, it is considerably more than that, as evidenced by the performance of the antenna.

It should be understood that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modification of the example of the invention herein chosen for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

l. A hybrid antenna comprising in combination:

a cylindrical inner conductor,

two tubular cylindrical outer conductors arranged in axial alignment with their respective inner ends spaced from each other, and concentrically spaced around said inner conductor,

each of the respective outer ends of said outer conductors being substantially in alignment with one of the outer ends of said inner conductor, insulating spacer means located between said inner conductor and each of the inner ends of said outer conductor to maintain concentricity between said conductors,

electrically conductive members located near the outer ends of said inner and outer conductors for completing an electric circuit thereinbetween and for securing said conductors in spaced relationship with each other, a plurality of capacitor disks located on each of said outer conductors adjacent the remote ends thereof, and

means for connecting insulated output leads to the inner ends of said outer conductors. 2. The invention as defined in claim 1 further comprising clamping means connected to said inner conductor, and a vertical mast attached to said clamp whereby said antenna will be clamped to said mast with said conductors thereof extending substantially at right angles to said mast.

Claims

1. A hybrid antenna comprising in combination: a cylindrical inner conductor, two tubular cylindrical outer conductors arranged in axial alignment with their respective inner ends spaced from each other, and concentrically spaced around said inner conductor, each of the respective outer ends of said outer conductors being substantially in alignment with one of the outer ends of said inner conductor, insulating spacer means located between said inner conductor and each of the inner ends of said outer conductor to maintain concentricity between said conductors, electrically conductive members located near the outer ends of said inner and outer conductors for completing an electric circuit thereinbetween and for securing said conductors in spaced relationship with each other, a plurality of capacitor disks located on each of said outer conductors adjacent the remote ends thereof, and means for connecting insulated output leads to the inner ends of said outer conductors.

2. The invention as defined in claim 1 further comprising clamping means connected to said inner conductor, and a vertical mast attached to said clamp whereby said antenna will be clamped to said mast with said conductors thereof extending substantially at right angles to said mast.