US3754269A - Omni-directional antenna mounted in circular radome - Google Patents

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Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q1/00—Details of, or arrangements associated with, antennas
  • H01Q1/40—Radiating elements coated with or embedded in protective material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Definitions

• the television antenna of the preferred embodiment comprises a layer of flexible non-conductive material, such as mylar, on top of which is affixed a plurality of strips of flexible conductive material. Electrical leads are connected to the flexible strips of conductive material [52] U.S. Cl. 343/742, 343/872 and the entire flexible structure is then placed on a Int. Clhousing.
• housing comprises a circular nomconductive She.
• the present invention relates to antennas and more particularly, to an improved omni-directional antenna for use with television receivers and/or FM receivers.
• Yagi-type antenna arrays In the field of antennas, it has been the general practice to employ dipole antennas. These dipole antennas have not proved entirely satisfactory and subsequently, Yagi-type antenna arrays were developed.
• the Yagitype array usually employed an active or radiator element, in combination with one or more directors and- /or reflectors. The use of these several elements widen the frequency response of the antenna when compared with a simple dipole antenna. Because these antennas were directional in nature, certain difficulties arose since they would only pick up signals from the direction in which the antenna was oriented. In an attempt to overcome these difficulties, omni-directional antennas have been developed.
• the general purpose of this invention is to provide an improved, omni-directional antenna which provides a greater signal to noise ratio then previous omnidirectional antennas and is less expensive to manufacture or fabricate.
• the present invention contemplates a unique arrangement wherein all conductive elements of the antenna are constructed from a flexible conductive material which is laminated to a flexible strip of non-conductive material such as mylar.
• the conductive elements which are laminated to the mylar material are arranged in a preselected pattern and, in the preferred embodiment, comprise 11 uniform strips of flexible copper foil which are placed adjacent to each other in parallel arrangement and a preselected number of these strips are then electrically connected together by a suitable connecting means.
• the laminated structure is then attached to the interior of a rigid non-conductive housing in a circular arrangement, thereby forming the omni-directional antenna.
• an object of the present invention is to provide an improved, omni-directional antenna which is capable of 360 reception and which provides a high signal to low noise ratio.
• Another object is to provide an omni-directional antenna which utilizes flexible active elements.
• a further object of the invention is to provide an omni-directional antenna which is impervious to metallically corrosive elements.
• Still another object is to provide an omni-directional antenna which is extremely simple and inexpensive to fabricate and at the same time easy to install and main"- tain.
• FIG. 1 is a top plan view of a flexible antenna segment which constitutes a preferred embodiment of the invention.
• FIG. 2 is a section of the flexible antenna segment taken on the lines 2-2 of FIG. 1.
• FIG. 5 is an exploded view of a flexible antenna segment of FIG. 1 in combination with a rigid housing.
• FIG. 6 is a perspective view, with a portion removed
• FIG. 1 a flexible antenna segment 10.
• the flexible antenna segment 10 is a laminated structure comprising a flexible non-conductive layer 12 and a flexible layer of conductive material 14.
• the layer of flexible conductive material 14 comprises a plurality of strips of flexible conductive material 16 which are arranged in a preselected pattern on the flexible non-conductive layer 12 and, as will be explained below, the strips of flexible conductive material 16 are permanently affixed to the flexible non-conductive layer 12.
• eleven strips of flexible conductive material are arranged so as to be parallel to each other and spaced apart an equal distance from each other, thereby forming eleven parallel spaced apart strips of flexible conductive material 16a through 16k.
• the flexible antenna segment 10 is of preselected length having a first end 17 and a second end 19. In the preferred embodiment, its length in inches is equal to one quarter wave length of channel 2 or 64 A inches.
• a conductor 18 electrically connects to each other four of the strips of flexible conductive material, while the remaining seven strips of flexible conductive material 16 are electrically connected together by a conductor 20.
• the strip of flexible conductive material 16a is segmented at its center by an aperture 22, thus forming two individual flexible conducted strips 24 and 26.
• the flexible conductive strip 26 is electrically connected to the conductor' 20 while the flexible conductive strip 24 is electrically connected to the strip of flexible conductive material 16b by another conductor 28.
• a conventional antenna lead 30 is connected to the flexible antenna segment 10 by any suitable fastening means. In the preferred embodiment, a pair of snap fasteners 46 and 48 are employed.
• the antenna lead 30 may be conventional twin lead wire wherein the first lead wire 30a is electrically connected to the conductor 18 while the second lead wire 30b is electrically connected to the conductor 20. In this manner, all eleven of the strips of flexible conductive material through 16k are electrically connected to the antenna lead 30.
• the antenna lead 30 may then be utilized to connect the flexible antenna segment 10 to a utilization device such as a television set or other similar device.
• any conventional roll feeding machine that is adapted to feed rolls of continuous material to a receiving station may be utilized.
• a roll 32 of flexible nonconductive material 12 is mounted on a feed roller means 33 and is fed to a receiving station 34.
• the flexible non-conductive material is treated with a heat resealable polyester adhesive.
• This heat resealable polyester adhesive may be applied to the flexible nonconductive material 12 as it is traveling to the receiving station 34 by any suitable means or the roll 32 of the flexible non-conductive material 12 may already have been treated by the manufacturer of the flexible nonconductive material with a heat resealable polyester adhesive.
• the width of the roll 32 is designed so as to be the same width as the desired width of the flexible antenna segment 10. In the preferred embodiment, the roll 32 has a width of seven inches.
• Continuous lengths of flexible conductive material 16 are also fed to the receiving station 34. These continuous lengths of flexible conductive material 16 are fed from a plurality of rolls 36 of preselected width which are mounted on a feed roller means 37. As can be seen in FIG. 2, the roll 36 of flexible conductive material 16 are located directly above the roll 32 of flexible nonconductive material 12 and as the flexible conductive material 16 is fed towards the receiving station 34, they are superposed above the flexible nonconductive material 12. As mentioned previously with reference to FIG. 1, the flexible antenna segment comprises in the preferred embodiment, eleven strips of flexible conductive material 16a through 16k. Therefore, it is necessary to utilize l 1 rolls 36 of flexible conductive material 16. It will be recognized, however, that if it is desired to utilize fewer than eleven strips, then fewer rolls 36 will be required and, likewise, if a greater number of strips were desired, then a greater number of rolls 36 will be required.
• each of the rolls 36 are then fed through an alignment apparatus 38.
• the alignment apparatus 38 insures that each of the flexible strips 16 are maintained at a preselected spaced distance from each other.
• the desired spacing may be determined empirically and, in the preferred embodiment, it is desired to maintain a spacing of 0. l 25 inches between the strips.
• Each of the strips of flexible conductive material 16 in the proposed embodiment are each one-half inch wide and the rolls 36 of this width may be obtained by slitting a larger roll of flexible conductive material into individual rolls one-half inch wide.
• the flexible conductive material 16 comprises a soft rolled copper foil which may be purchased commercially from many sources.
• the plurality of strips of flexible conductive material 16 and the strip of flexible non-conductive material 12 are continuously fed to the receiving station 34.
• each of the strips of flexible conductive material 16 are bonded or affixed to the upper surface 13 of the flexible non-conductive material 12.
• the upper surface 13 of the flexible non-conductive layer 12 has been treated with the heat resealable polyester adhesive.
• a conventional set of hot rollers applies both pressure and heat to each of the strips of flexible conductive material 16, thereby sealing or affixing each of the flexible conductive strips 16 to the upper surface 13 of the flexible non-conductive material 12, thereby forming a continuous laminated flexible conductive material 40.
• the continuous laminated flexible material 40 may then be formed into a roll 42.
• the flexible antenna segment 10 may be manufactured by merely cutting the continuous laminated flexible material 40 into segments 10 of proper length.
• the flexible antenna segments 10 are cut to a length of 64 1% inches.
• 64 1% inches represents one quarter wave length, in inches, of television channel 2.
• the strips of flexible conductive material 16a, 16b, 16c, 16d, 16e, 16f, and 16g are electrically connected together by a conductor 20.
• the conductor 20 may comprise a copper conductor which is welded to the layer of flexible non-conductive material 12 and to the strips of flexible conductive 16a through 16g. Similarly, the strips of flexible conductive material 16h through 16k are also electrically connected in the similar manner by the conductor 18. As also mentioned previously, the segment 24 of the flexible conductor 16a is electrically connected by a conductor 28 to the strip of flexible conductive material 16b. As can clearly be seen in FIG. 3, this connection is only made on the upper surface 13 of the flexible non-conductive layer 12. However, if it is desired, a two-sided connection may be utilized.
• the segments 24 and 26 are shown to be of equal length in the preferred embodiment.
• the aperture 22 is placed exactly in the center of the strip of flexible conductive material 16a. This positioning was determined empirically and it has been found that the best reception is obtained when the aperture 22 is positioned a good distance from each end of the strip of flexible conductive material 16a. However, other placements may be utilized.
• the antenna lead 30 is electrically connected to the conductors l8 and 20 by any suitable fastening means.
• the snap fasteners 46 and 48 are inserted into the flexible, non-conductive layer 12 and the flexible conductive layer 14, as well as contacting each of the conductors 20 and 18, as shown in FIGS. 1 and 2.
• the snap fasteners 46 and 48 are identical.
• the snap fastener 46 comprises a male portion 45 and a female portion 47.
• the upper part 45a male portion 45 is in electrical contact with the conductor 18 while the female portion 47 is in electrical contact with the antenna lead 30a or 30b.
• this antenna segment may then be coated with a protective non-conducting coating. Any suitable protective coating, such as plastic, may be utilized. If it is desired, rather than utilizing plastic coating, a secodn layer of Mylar can be placed over the layer of flexible conductive material 16, thereby forming a three-layer flexible antenna segment having the layer of flexible conductive material 16 sandwiched in between two layers of flexible non-conductive Mylar 12.
• the flexible antenna segment is then affixed or bonded to a rigid housing.
• the housing In the preferred embodiment, it is desired to make the antenna omni-directional and, therefore, the housing must be circularly shaped.
• FIG. 5 a preferred housing 50 is shown.
• the housing 50 comprises an upper segment 52 and a lower segment 54.
• the upper segment 52 is generally circularly shaped and has a circular rim 56 from which downwardly protrudes a cylindrically shaped extension 58.
• the dimensions of the cylindrically shaped extension are such that the flexible antenna segment 10 is wrapped around the outer surface 60 of the cylindrically shaped extension 58.
• the flexible antenna segment 10 When wrapped in this manner, and affixed or bonded to the housing, a space is formed between the first end 17 and the second end 19 of the flexible antenna segment 10.
• the flexible antenna segment 10 may be bonded to the rigid housing by any suitable means such as a cementor by heat.
• the lower segment 54 of the housing 50 is again mated with the upper segment.
• the upper segment acts as a male member
• the lower segment 54 acts as a female member thereby forming a compact circular donut-shaped housing wherein the flexible antenna segment 10 is completely protected from any corrosive elements.
• a support bar 62 may then be placed across the opening in the housing 50 and a shaft (not shown) may then be connected to the support 62 to mount the antenna in a conventional manner.
• the housing 70 is generally shaped in the form of a hemisphere.
• the upper portion 72 of the hemisphere comprises a vertically shaped segment 74 which is adapted to receive the flexible antenna segment 10.
• the width of this vertically shaped segment 74 is made slightly greater than the width of the flexible antenna segment 19 and, in the preferred embodiment, is 7 V4 inches tall.
• the circumference of the housing 70 is slightly larger than the length of the flexible antenna segment 10.
• the flexible antenna segment 10 is bonded or attached to the interior surface of the vertical segment 74.
• a cover may be affixed to the lower open end of the housing 70, thereby closing the housing and thereby making the antenna completely impervious to corrosive elements.
• housing 50 is utilized or housing 70 is utilized and, fur thermore, any otehr similar housing may be employed without departing from the spirit and the scope of the invention.
• the preferred embodiment utilizes eleven strips of flexible conductive material connected together in several groups.
• the actual connections and dimensiosn of this antenna have been found empirically and provide the best television reception over channels 2 through 13 as well as the UHF channels.
• the dimensions of this antenna are provided below; however, it is to be recognized that these dimensions are merely illustrative of the invention, and various modifications may be made without departing from the spirit and the scope of the invention.
• the flexible non-conductive material utilized in the preferred embodiment is mylar an it two mills thick. An adhesive coating l k mills thick is applied to one surface of the mylar.
• the flexible conductive material utilized is rolled copper foil which is 0.0014 inches thick and is k inch wide.
• the purity of the copper is rolled 99.9 percent.
• the resistivity of one ounce of this copper is 0.15940 ohm-gram meter at 20 centigrade.
• the tensile strength is equal to 50.
• the connectors 18 and 20 are manufactured from a copper alloy and are one inch wide.
• the strips of flexible conductive material 16 are affixed to the mylar at the receiving station 34.
• the receiving station 34 applies a pressure of 30 psi at 325 F. to each of the strips of flexible conductive material 16 thereby bonding the strips of flexible conductive material 16 to the flexible non-conductive layer 12.
• the space between each adjacent strip of flexible conductive material 16 is approximately 0.125 inches.
• An omni-directional television receiving antenna comprising:
• each of said-strips of flexible conductive material includes a first end and a second end and wherein each of said strips of flexible conductive material are affixed to said layer of flexible non-conductive material;
• a rigid non-conductive circular housing wherein said layer of flexible non-conductive material is affixed to the interior of said housing whereby said first end of each of said conductive strips is placed adjacent to its respective second end of said conductive strips thereby forming a plurality of substantially circularly shaped conductive elements.
• the omni-directional antenna of claim 1 further comprising:
• the omni-directional antenna of claim 1 wherein said antenna comprises 11 parallel strips of flexible conductive material affixed to said non-conductive material.
• the omni-directional antenna of claim 4 further comprising:
• third means for electrically connecting together the first ends of the remaining seven of said conducting strips thereby forming a second group of conductive elements.
• the omni-directional antenna of claim further comprising:
• fourth means for electrically connecting the other of said bisected segments to another of said strips of conductive material in said second group of conductive elements.
• the omni-directional antenna of claim 8 wherein said first means comprises a twin lead wire and wherein one of said leads is electrically connected to said first group of conductive elements and wherein the other of said leads is electrically connected to said second group of conductive elements.
• each of said leads are electrically connected to said conductive elements by a snap fastening means.
• the omni-directional antenna of claim 3 wherein said first means is electrically connected to said strips of flexible conductive material by a snap fastening means.

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Abstract

Description

Claims (11)

Applications Claiming Priority (1)

Publications (1)

Family

ID=22873641

Family Applications (1)

Country Status (3)

Cited By (192)

Citations (3)

• 1972
  • 1972-03-07 US US00232562A patent/US3754269A/en not_active Expired - Lifetime
  • 1972-11-27 JP JP47118799A patent/JPS491156A/ja active Pending
• 1973
  • 1973-02-16 DE DE19732307726 patent/DE2307726A1/en active Pending

Patent Citations (3)

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