US 2943326 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
June 28, 1960 A. C. THAYER v TELEVISION ANTENNAS Filed Feb. 16, 1955 2 Sheets-Sheet 1 FIG. 2
INVEN TOR. ARTHUR C. THAYER FIG. I
ATTORNEYS June 28, 1960 Filed Feb. 16, 1955 A. c. THAYER 2,943,326
TELEVISION ANTENNAS 2 Sheets-Sheet 2 IN VEN TOR. ARTHUR C. THAYER ATTORNEYS 2,943,326 TELEVISION ANI'ENNAS Arthur C. Thayer, Rte. 3, Clare, Mich. Filed Feb. 16, 1955, Ser. No. 488,477 s-ciaims. (Cl. 343-817) This invention relates'generally to antennas and more particularly to atelevision antenna of extremely simple and practical construction which provides a high gain on all channels in both the low and high frequency bands.
As is well known so called high gain antennas which have been used} in fringe reception areas have been of more or less elaborate construction and have employed elements of adequate size to resonate at particular desired frequ ncies. Such antennas have been generally designed to receive the signal of a certain station and have comprised relatively complicated directive parasitic arrays which provide a relatively high gain at certain frequencies, but receive onlya'liinited spectrum of frequencies. These normally expensive antennas. havenot been particularly saleable in the more populated areas where an antenna receiving a wider" range of frequencies as well as having a high gain for receiving distant stations is desired since in these areas it will often be possible to receive .a plurality of stations which are broadcasting at frequencies in both thelo'w and high bands v} One of the prime objects of the instant invention is to design an all-channel broad band antenna which provides a high gain over a wide range of frequencies and is well suited to receiving signals from broadcasting stations which are at varying distances from the site.
Another object of the invention is to design an antenna of the type described which is unobtrusive in appearanee and is not sufiiciently bulky to attract attention.
A further object of the invention is to design an antenna of this type which has an excellent front to back ratio and'will not pick up undesired signals coming from the rear so that co-channel interference is no problem. Such an antenna will also be useful where a reflection from some object behind the antenna is causing ghost images on the viewing screen since the ghost signal will he reduced to a point Where it will not interfere with .the direct signal because the antenna will not respond to signals behind it. v p
Another object of the invention is to design an antenna in which the quality of the signal is not impaired in passing through theantenna and the picture on theviewing screen will not be distorted, or lack contrast, or picture :definitionJ A furtherobject of theinvention is to design an antenna which is of compact construction so that it can be easily and safely handled during installation and is dynamically balanced so thatit' may be used with a rotating mast. I
Another object. of the invention is, to provide an antenna' of streamlined and rugged design which will stand up under extreme weather and icingrconditions.
A fu'rtherobject of the invention is to provide an antenna of the type described which comprises antenna poles which may be readily stored-and assembled-by jobber s and *de'a le'rsonf theirpremises and transported in their trucks to the assembly site-where they may be very 'easi-ly'clamp'ed in position l on a' boom or mast. Another object of the invention is to provide a :broad.
Patented June 28,. 1960 bandrantenna-which will have sufhcient gain in fringe areas to obtain signals of a strength which will override noises and interferences which are picked up bythe re ceiving system.
A still further object of the invention is to provide an antenna of the type described which is extremely simple in design and can be manufactured and erected at relatively low cost.
With the above and other objects in view, the present invention consists in the combination and arrangement of parts hereinafter more fully described, illustrated in V the accompanying drawings, and more particularly pointed out in the appended claims, it being understood that changes may be made in the various elements Whicli comprise thereof. H
ln the drawing:
Fig. 1 is an end elevational view' of the antenna. Fig. 2 is an enlargedfragmentary top plan view of one of the vertically stacked poles thereon, the pole being inverted from the position in which it is shown in Fig. l, and being partly in section to illustrate the .connection of one of the lead-off wires from the pole.
Fig, 3 is a side elevational view of one of the poles shown in Fig. l. i
Fig. 4- is a tranverse sectional view taken on the line -e of Fig. 2. V
Fig. 5 is a tranverse sectional view taken on the line 5-5 of Fig. i
Fig. 6 is a view similar to Fig. 5 illustrating embodiment of the invention.
Fig. 7 is a similar view illustrating a further embodiment of the invention.
Fig. 8 is a similar view illustrating still a further embodiment of the invention and,
Fig. 9 is a similar view indicating another modified embodiment of the invention.
Referring now in detail to the accompanying drawings and first of all particularly to Figs. 1-5 thereof, a letter A generally indicates myantenna which includes a standard tubular boom or mast 10. The mast 10 which is preferably formed of a light weight metal such as aluminum may be mounted in a socket on the roof or the like in the conventional manner or may be mounted in a rotator since as will appear later the antenna is dynamically balanced. Provided on the boom at properly spaced apart intervals are dipole-like members which I shall generally designate 11, 12, 13, and 14, and it is to be understood that there could be fewer or more spaced pole members and the invention is in no manner to be restricted to the number shown, although preferably an even number of these horizontal members are employed. I use the term dipole-like because a strict definition of the term dipole requires that two conductors of one quarter wave length relative to the particular frequency which is to be received be located in a parallel plane. The dipole-like members11-14 are spaced apart a' distance which will cause the signals to be in phase at the terminals where the main transmission line T is connected as is conventionally done so that the amplitudes of the 7 another element currents are notv influenced by the mutual imand 17 comprise central rings" 18a which are mounted on the boom 10 and clamped thereto are arms 18b hav- -ingstandard Bakelite insulating blocks 18c 01 the like .to
the inventionwithout departing from the spirit support the rods 16 and 17. Setscrews 18d may be employed to clamp the spacers 18 in position on the mast and the rods 16 and 17 are secured to the blocks 18c in any suitable manner. The 300 ohm wires 15 and the lead-in or transmission wires 19 to the receiver (load) are connected to suitable terminals on the members 18c which electrically connect with the metallic rods 16 and 17 and I do not deem it necessary to show these terminals in detail since they are conventional. In fact the entire system depicted for transferring the signal picked up by the various poles 11-14 to the receiving set in a manner such that the irnpedances of the antenna, transmission line 19a, and receiver are properly matched is conventional and the transformer rods 16 and 17 are, of course, employed to maintain a relatively constant terminal impedance over the broad spectrum of frequencies which may be received.
The invention herein resides in the dipole-like members 11-14 which are identical in construction so that a description of any one of them will suflice for all. As will be apparent thesemembers may be very readily mounted in position on the mast 10. Each pole 11-14 includes a pair of elongated non-conductors or dielectric supports 20 and 21 which are chevron shaped in cross section (see Fig. and may be formed of wood or any other relatively inexpensive non-conductive material such as a plastic or the like. Parallelly arranged, angular, clamping members 22 and 23 conforming to the 90 angularity of the members 20 and 21 receive the inner ends of these members and a bolt 24 connects bothmembers 22 and 23 and extends through the tubular mast so that a nut 25 may be tightened down to clamp the pole on the rod as well as to clamp the non-conductors in position. Interposed between the clamping members 22 and 23 and members 20 and 21 are insulating strips I of moisture resistant plastic or the like which although .the members 20 and'21 may be formed of wood assure that there will be no current leakage from conductive 'strips on these members in wet weather or the like. It
will be observed that the angle members 22 and 23 are angular in'a longitudinal plane also, so that the members 2t) and 21 extend outwardly at a slight angle toward the distant transmitter. Further, as will be seen in Fig. 2 the non-conductors 20 and 21 which are of relatively large cross section adjacent the mast 10 taper uniformly outwardly.
Mounted on the angularly concaved faces of the nonconductors 20 and 21 are elongated, similarly angular, metallic conductor strips 26 which may be formed of a foil-like aluminum sheet or any other good strip conductor, and mounted on the opposite sides of the members 20 and 21 in horizontal alignment with the strips 26 are substantially identical reflector strips 27. It is important to note that the use of the term foil or foil-like I is not intended to restrict the strips employed to any particular thickness. These strips 26 and 27 may be secured in position by annular plastic retaining rings 28 and are also cemented to the non-conductors with non-conducting cement. The members 20 and 21 of the poles 11-14 are of identical construction and length and clearly extend oppositely from the mast 10 so that the antenna will be in good dynamic balance and may be rotatably mounted.
In order to avoid current leakages and to still provide connections for the wires and strips 26 which are readily accessible and inexpensively constructed specially designed terminals are provided which are particularly adapted to the members previously described. A triangular block of wood 29 or the like is covered except at its' ends with a strip of conductive aluminum 30 and an aluminum bolt 31 is provided to secure the block 29, the bolt having a non-conductive and non-moisture abr sorbent plastic washer 32a and a plastic sleeve 32 which extends through the support or 21, and strip 26. One of the wires 15 may then be looped around the extending end of the bolt which has nuts 31a and washers 33 thereon between which the wire may be clamped. It will be observed that the reflector strips 27 terminate short of the strips 26 at their inner ends so that they avoid the terminal just described, however, the reflector strips 27 will extend to the end edges of the members 20 and 21 while the strips 26 will terminate slightly short thereof so that the strips 26 and 27 are of substantially the same length. This length is gauged to the broad band of frequencies which are to be picked up so that optimum results will be obtained as are the connected conductors and reflectors of conventional television antennas. In the instant application the length of the strips 26 will be something over one quarter wave length, each resonated to one of the low frequencies in the frequency spectrum which will be received so that over this band of frequencies those which will be received are closest to the resonance points of the strips 26.
In practice the antenna is rotated so that the strips are substantially broadside to the approaching signal of the station it is desired to receive. Of course, both strips 26 on a given pole cannot be perpendicular to the approaching signal because of their relative angular disposition, however, as noted, the strips are inclined toward the distant station.
Experiments have indicated that the instant antenna provides at least twice as much gain on all channels in both the low and high frequency bands as do conventional all-wave antennas. This it is believed is a result of the construction of the poleswherein closely spaced conductor and reflector elements in horizontal alignment are separated by a dielectric and wherein the surfaces of the connected conductor strips are angular so that there is a pickup of reradiation from one portion of a strip at the other portion thereof.
It is, of course, conventional practice to employ resonant reflector rods of circular cross section at a spaced distance in air from a conductor rod of circular cross section to modify the oncoming electromagnetic fields in their vicinity. Such reflector rods intercept more wave energy than if they were metallically connected to a load but must, however, reradiate all of the energy intercepted whereas the conventional connected rod transmits one half of the wave energy intercepted and reradiates the other half. The parasitic reflector rod is thus exposed to the original wave plus a retarded one reradiated by the conductor rod and reradiates the whole so that this latter reradiation may again feed the conductor rod which once again transmits half the wave energy intercepted and reradiates the remainder. The problem has been timing or phasing since the distances traveled by the original wave and reradiated waves have varied and this timing has been controlled by the distance between the parasitic and connected element in air and by the length of the parasitic element. I have discovered that if a horizontally disposed connected conductor element and reflector are closely spaced apart and separated by a dielectric the reradiation effect is greatly enlarged and the gain of the array is considerably increased. By closely spaced apart I mean a distance which might be .05 of a low frequency wave length to be received (measured in hundredths) as distinguished from conventional spacing which is usually maintained close to one quarter of the wavelength to maintain a phased relationship. This is particularly true where the connected element and reflector comprise thin strips having a large capture area and is augmented by the angularity of the connected strips themselves and the reradiation which takes place between the portions of a given strip. No timing problem is experienced because the distances traveled in the reradiation are so short in comparison to the wavelength being received. An antenna of the type which I have described ideally incorporates the principles which are involved in the invention and canbe more economically manufactured and sold than conventional antennas. The dielectric or nonconductive separators, are employed as the support poles and insulate the connected conductor from the mast. Since wooden poles may be employed instead of the conventional poles which are fabricated of aluminum or steel obviously the cost of manufacturing the antenna can be decreased. Because of the configuration of the poles the metallic strips which are employed therewith will be relatively wide with relation to the size of the streamlined poles which are employed and will have a greater capture area for collecting waves. While the performance of the antenna is thus improved the signal received, unless the antenna is exceedingly close to a transmitter, will not exceed safe values such as to create undesired overloading at the first tube of the receiver. Another feature to be consideredwhere the dielectric separates the connected element and reflector is the lack of signal response behind the connected element which results in what is known as an excellent front to back ratio so that co-channel interference or reflector caused ghosts (reflection from objects other than the strips 27 and located rearwardly of the antenna) create no problems.
In Fig. 6 I have shown another modification of the invention in which the dielectric pole 120 is of circular cross section and the connected conductor 126 and reflector conductor 127 are applied thereto as shown. Otherwise the construction is identical and while this is not as high gain an antenna as that previously described because the strips 126 and 127 are not angular and respective portions of each strip 126 do not intercept radiations from one another still the performance of such an antenna would be superior to that of known antennas and obviously the cost of manufacture would be considerably less.
Fig. 7 shows a pole which is substantially like that described in Figs. 1-5 except that the dielectric pole supports 220 are tubular and obviously their operation and performance will be virtually the same.
In Fig. 8 I have shown a tubular pole support 320 which is diamond shaped in configuration and has strips 326 and 327 thereon. The operation and performance of this embodiment which is otherwise identical with the preferred embodiment shown is similar to that of the embodiment shown in Fig. 6.
Fig. 9 shows a semicylindrical, concavo-convex tubular support pole with strips 426 and 427'. The operation and performance is much like that ofthe embodiment shown in Figs. 1-5 with which the antenna is otherwise identical except that there may not be as much reflection or reradiation between the various port-ions of the connected conductor strip.
It should be apparent that I have perfected a greatly improved antenna and it is to be understood that various equivalent changes in the antenna shown and described may be made without departing from the spirit or principles of the invention or the scope of the subjoined claims.
1. A television antenna comprising a pair of relatively narrow, elongate dielectric support pole members of substantially V-shaped cross section and of a predetermined equal length arranged in generally longitudinal disposition, elongated angular conductor dipole foil st-rips extending substantially from end to end of said poles sealed to the recessed surfaces of said V-shaped pole members, elongated angular reflector strips on the opposite surfaces of said poles a spaced distance from and substantially parallel with said first mentioned strips, terminals in contact with the first mentioned strips near the adjacent ends thereof, and a transmitting line connected to said terminals.
2. The combination defined in claim 1 in which said terminals comprise triangular blocks covered except at their ends with conductor foil and conductor posts projecting therefrom.
3. The combination defined in aim 11 when a d pole. members are tapered" and et ntna' ing s m-able over the outer reduced. ends of said members secure said foil: strips in position.
4. The combination defined in claim 1" in which said reflector strips terminate short: of terminals but extend further toward the end edgesof said polemembers than said'strips in the recessed surfaces.
A, 5. A television antenna comprisinga boom, a pair of spaced angle, members secured to s tl"boom, outwardly extending dielectric pole members, chevron shaped "in cross section, with their inner ends clamped between said angle members, elongated conductive angular strips covering the recessed surfaces of said pole members substantially from end to end thereof, elongated conductive angular strips covering the opposite diverging faces of said members, and take off conductors connected to each of said strips in the recessed surfaces near the adjacent ends thereof.
6. In a television antenna, a mast, a pair of horizontally spaced, diverging, angle members mounted on said mast, a pair of elongated linear dielectric pole members, chevron shaped in cross section, having an end of each clamped between said angle members and extending outwardly therefrom in a horizontal plane, said members being of identical predetermined length and tapering uniformly from their inner ends to their outer ends, elongated angular, conduetor dipole strips covering the marginal walls of the indented faces of said members, elon gated angular conductor strips covering the diverging walls of the opposite faces of said members, triangular conductor blocks filling said indented portion of said dielectric members and electrically in contact with said strips in the indented faces of said members, and transmission line terminals on said blocks, said strips on the diverging walls of said opposite faces terminating just short of said terminals but extending tothe ends of said pole members, and said strips in contact with the terminals terminating just short of the ends of said pole members so that all conductor strips are of substantially the same length;
7. A television antenna for television signal reception comprising an elongated, rigid, non-conductor member having a recess in one face extending substantially the length thereof and defining generally convergent, marginal side wall portions; a pair of generally co-extensive, elongated, electrically separated conductive strip means extending along said dielectric member on the exposed outer surface thereof lengthwise thereof and secured in facial engagement therewith over their length, the strip means being separated one from the other a closely spaced perimetral distance and generally oppositely disposed, said one of said strip means being shaped to lie in facial engagement with said generally convergent, marginal side wall portions; conductive transmission means connected electrically to one of said strip means; and means for supporting said antenna.
8. A television antenna for television signal reception comprising; an elongated, non-conductive, rigid member generally chevron-shaped in cross section and having a recessed outer side surface and an opposite outer side surface connected by edge surfaces; a pair of generally co-extensive, elongated, conductive foil strip means extending lengthwise of said dielectric member; one strip means being secured in facial engagement with the recessed side surface of said non-conductive member over the length of the strip means and the other strip being secured in facial engagement with the directly opposite side surface; said strip means substantially spanning said side surfaces from edge surface to edge surface and being separated electrically one from another by said edge surfaces; transmission means connected electrically to the strip means on the recessed surface; and mast means 7 for supporting said non-eonduetive member connec ted FOREIGN PATENTS thereto in a manner to be insulated from said strip means. 510,172 1 Canada Feb. 15,1955 References Cited in the file'of thiS patent" 892360 France 1944 UNITED STATES PATENTS A V 6 OTHER REFERENCES 2,505,098 Cornelius Apr. 25, 1950 White: A Paste Pot Beam for 10, CQ, March 1949, 2,608,658 Richards Aug. 26, 1952 p g 20. 2,714,659 Johnson e1; a1. Aug. 2, 1955 The A.R.R.L. Antenna Book, American Radio Relay 2,769,170 Clogston Oct. 30, 1956 0 League, page 160, 6th edition, 1954.
2,789,286 Marshall Apr. 16, 1957