US2655600A

US2655600A - Stacked antenna array for television signal reception

Info

Publication number: US2655600A
Application number: US179593A
Authority: US
Inventors: Harold R Hillison
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-08-15
Filing date: 1950-08-15
Publication date: 1953-10-13
Anticipated expiration: 1970-10-13

Description

Oct. 13, 1953 H. R. HlLLlSON STACKED ANTENNA ARRAY FOR TELEVISION SIGNAL RECEPTION Filed Aug. 15, 1950 Patented Oct. 13, 1953 UNITED STATES PATENT OFFICE STACKED ANTENNA ARRAY FOR TELE- VISION SIGNAL RECEPTION 1 Claim.

This invention relates to antenna arrays and more particularly to a selective antenna array for television reception.

It is among the objects of the invention to provide an improved antenna array which will accurately discriminate between the signals from broadcast stations located in different directions from the antenna, giving uniform gain to the signals from a selected station and rejecting the signals from the other station or stations, which will receive signals on all frequency channels in current use with equal effectiveness, which has a high front to back reception ratio and high selectivity for different frequency channels, which operates effectively with the transmission lines currently in use, and which is mechanically simple and economical to manufacture, strong and durable in construction, and easy to install and adjust.

Other objects and advantages will become apparent from a consideration of the following description and the appended claim in conjunction with the accompanying drawing wherein the single figure is a perspective view of a stacked antenna array illustrative of the invention.

With continued reference to the drawing, the antenna array therein illustrated comprises an elongated mast I formed of a suitable structural member, such as a metal tube, and adapted to be mounted in upright or substantially vertical position on a suitable support such as the building chimney II. 1

A first crossarm I2 is mounted on the mast Ill above the support I I by a suitable sleeve bracket I3 having one sleeve portion slidably receiving the mast and another sleeve portion slidably receiving the crossarm I2 which crossarm may comprise a length of metal tubing of suitable length and diameter. The crossarm I2 is disposed substantially perpendicular to the mast I0 and projects to opposite sides of the mast for a purpose to be later explained.

A second crossarm I4 is mounted on the mast above the crossarm I2 by a sleeve bracket I5 similar to the sleeve bracket I3 and is disposed substantially perpendicular to the mast. The crossarm I4 also extends to opposite sides of the mast and the two crossarms I2 and I! have their longitudinal center lines substantially in a common plane which also includes or is parallel to the longitudinal center line of the mast It.

It has been found that for current operating conditions a distance of approximately twenty eight inches between the two crossarms gives optimum operational results.

Each of the crossarms constitutes a component of a separate antenna assembly and the two antenna assemblies carried in vertically spaced apart relationship by the mast II] constitute the antenna array of the invention.

The lower antenna assembly comprises a refiector I6 mounted on one end of the crossarm I2 by a sleeve bracket I I. This reflector is disposed substantially at right angles to the mast m and the crossarm I2 and is mounted on the crossarm at its mid-length location. It may conveniently comprise a metal rod of approximately one half inch diameter and ninety four inches in length.

At the side of the mast remote from the reflector I 6 the crossarm I2 carries a low frequency channel dipole, generally indicated at It. This dipole I8 comprises two metal rods or bars I9 and 20 disposed in end to end relationship with their adjacent ends spaced apart approximately two and one half inches and secured in a sleeve bracket 2I of insulating material mounted on the crossarm I2 at a distance of approximately twenty six inches from the reflector I6. Each of the dipole rods or bars I9 and 20 may conveniently comprise a metal rod approximately three eighths of an inch in diameter and forty one inches long. The dipole I8 is substantially parallel to the reflector I6 and substantially perpendicular to the crossarm I2 and the'mast I0 and is symmetrically disposed relative to the crossarm.

A conventional three hundred ohm transmission line 22 extends along the mast and is provided at its upper end with two leads 23 and 24 which are connected to terminals 25 and 26 respectively, carried at the respectively opposite ends of a terminal block 27 of electrically insulative material mounted on the mast It between the crossarms I2 and. I4. A conductor 28 leads from the terminal 25 to the dipole element I9 and a similar conductor 29 connects the terminal 2'! to the dipole element 20, the dipole elements I9 and 20 being thus connected to the transmission line leads 23 and 24 respectively.

A director 30 is mounted on the crossarm I2 at a location spaced from the side of the dipole I8 remote from the reflector I6 and mast It, and is substantially parallel to the dipole I8 and per pendicular to the mast IG and crossarm I2. This director 30 may conveniently comprise a metal rod of one half inch diameter and sixty four inches long spaced six inches from the dipole and symmetrically disposed relative to the cross arms. This director is mounted on the crossarm without electrical insulation, by suitable means, such as the sleeve bracket 3|, and is not electrically connected in any way to the transmission line.

A high frequency channel dipole, generally indicated at 32, is mounted on the crossarm at a location spaced from the side of the director remote from the dipole I8. The dipole 32 comprises two

elements

33 and 36 in the form of metal rods disposed in end to end relationship with their adjacent ends spaced apart a distance of approximately two and one half inches. Each of these rod elements may conveniently comprise a metal rod of approximately three eighths inches in diameter and approximately eighteen inches in length and are received at their adjacent ends in a sleeve bracket 35 of electrically insulative material mounted on the crossarm |'2. This second dipole is spaced approximately thirteen and.

three quarter inches from the director 35 and is substantially parallel to the director 33 and-symmetrically disposed relative to the crossarm |2.

An auxiliary director 68 is: mounted on crossarm |2 between director 33 and high frequency channel dipole 32 by a suitablebracket. G1 and is substantially parallel to the director 38 and, dipole 32. This director is shorter than director 30 and somewhat longer than dipole 32 and is slight ly closer to the adjacent dipole than to the adjacent director.

A second director 36 is mounted on the end of the crossarm |2 remote from the reflector l6 and comprises a metal rod or bar approximately one half inch in diameter and twenty four inches long spaced five inches from the side of the dipole 32 remote from the director 30. This second director 35 is substantially parallel to the dipole 32 and symmetrically disposed relative to the cross- .arm l2.

The reflector IS, the dipole Hi, the directors 30 and 60, the dipole 32 and the director 36 all have their longitudinal center lines substantially in a common plane which plane is substantially coincident with the longitudinal center line of the crossarm l2 and which plane is substantially perpendicular to the longitudinal center linev of the mast Hi.

The upper antenna assembly is similar in all respects to the lower antenna assembly described above and includes a reflector 31 similar in dimeter and length to the reflector l6 and mounted on one end of the crossarm l4 by a sleeve bracket 38 in position directly above and substantially parallel to the reflector IS. The upper antenna assembly further includes a low frequency channel dipole, generally indicated at 38, a. director 40, a high frequency channel dipole, generally indicated at 4|, an auxiliary .director 62 between director 40 and dipole 4| and a director 42 at the side of dipole 4| remote from auxiliary director 62.

The dipole 39 is similar in all respects to the dipole |8 and is disposed above and substantially parallel to the dipole I8. It includes two rod elements 43 and 44 disposed in end to end relationship and received at their adjacent ends in a. sleeve bracket 45 of insulative material mounted on the crossbar l4 at the side of the mast H) remote from the reflector 3! and spaced approximately twenty six inches from the re flector 31 and substantially parallel to the latter. The dipole element 43 is electrically connected. to the terminal 25 by a conductor 46 and the element 44 is electrically connected to the terminal 21 by a conductor 41.

The director 40 is mounted on the crossarm H by a sleeve bracket 48 and is disposed directly above and substantially parallel to the director 30. It is also substantially parallel to the dipole 33 and spaced approximately six inches from this dipole at the side of the latter remote from the reflector 31.

The dipole 4| comprises two rod or bar elements 49 and 50 disposed in end to end relationship and received at their adjacent ends in a .sleeve bracket 51 of electrically insulative material mounted on the crossarm M at a location spaced thirteen and three quarter inches from the side of the director 40 remote from the dipole 39.

The auxiliary director 62 is parallel to director 40 and dipole 4| and somewhat nearer the latter than the former. It is shorter than director 40 is secured on crossarm l4 by a bracket 63.

A vertically disposed Q bar 52 is electrically connected at its upper end to the dipole element 49 and at its lower end to the dipole element 33. A similar Q bar 53 is electrically connected at its upper end to the dipole element 50 of the dipole 5| and at its lower end to the element 34 of the dipole 32. A conductor 54 is electrically connected at one end to the Q bar 52 substantially at the mid-length location of this Q bar and is electrically connected at its other end to the terminal 26 on the terminal block 21 and a similar conductor 55 is electrically connected at one end to the Q bar 53 substantially at the mid-length location of this Q bar and is electrically connected at its other end to the terminal 25, the conductors 54 and 55 being crossed over or transposed between the Q bars and the terminals on the block 21. A collar 55 of electrically insulative material surrounds the two conductors 54 and 55 at the cross over location to prevent frictional movement of these conductors relative to each other.

The director 42 is similar to the director 36 and is disposed directly above and substantially parallel to the latter. It is substantially parallel to the dipole 4| and spaced approximately five inches from the side of this dipole remote from the director 40.

The above described construction provides an antenna array which has a high front to back reception ratio so that it will effectively discriminate between signals from broadcasting stations located at different sides of the antenna, pro-- viding a uniform gain for the signals from a selected brodcast station and rejecting signals from a station located at a diiferent side of the antenna. It is also highly effective in rejecting reflected signals, thus avoiding the condition usually referred to as ghost pictures on the television screen and is highly selective as to different channel frequencies providing sharp and clear pictures.

While the dimensions as given above have been found to be highly effective for broadcast channel frequencies currently in use, it is to be understood that these dimensions may be varied without in any way exceeding the scope of the invention.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claim rather than by the foregoing description, and all changes which come within the meaning and range 01 equivalency of the claim are, therefore, intended to be embraced therein.

What is claimed is:

An antenna array comprising a mast adapted to be mounted in substantially vertical position, and antenna assemblies carried by said mast in vertically spaced apart relationship relative to each other, said antenna assembliesbeingsubstantially identical and coextensive and each comprising a crossarm mounted on said mast and disposed substantially perpendicular thereto, a first dipole mounted on said crossarm and disposed substantially perpendicular to said crossarm and said mast, a reflector longer than said first dipole mounted on said crossarm and disposed substantially parallel to said first dipole at a location spaced from one side of the latter, a first director shorter than said first dipole mounted on said crossarm substantially parallel to said first dipole and spaced from the other side of the latter, a second dipole shorter than said first director mounted on said crossarm parallel to said first director and spaced from the side of the latter remote from said first dipole, a second director shorter than said secand dipole mounted on said crossarm parallel to said second dipole and spaced from the side of the latter remote from said first director, a terminal block mounted on said mast between said antenna assemblies, spaced apart terminals carried by said block, electrical conductors connecting the first dipoles of both assemblies to said terminals, Q bars interconnecting the second dipoles of both assemblies, and transversed conductors connecting said Q bars to said terminals.

HAROLD R. HILLISON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 23,273 Kearse Sept. 25, 1950 2,112,269 Carter Mar. 29, 1938 2,248,335 Burkhart July 8, 1941 2,292,791 Mims Aug. 11, 1942 2,380,519 Green July 31, 1945 OTHER REFERENCES Radio and Television News, September 1949, page 69.