Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2870443 A
Publication typeGrant
Publication dateJan 20, 1959
Filing dateApr 15, 1953
Priority dateApr 15, 1953
Publication numberUS 2870443 A, US 2870443A, US-A-2870443, US2870443 A, US2870443A
InventorsLynch Leonard J, Tishrock Harold H
Original AssigneeLynch Leonard J, Tishrock Harold H
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Television antenna
US 2870443 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

J 20, 17959 L. J. LYNCH ET AL 2,870,443

TELEVISION ANTENNA I Filegi April 15, 1953 Leonard J Lynch E Harozcz H z z'shrock,

United States Patent TELEVISION ANTENNA Leonard J. Lynch, De Kalb, and Harold H. Tishrock,

Evanston, Ill.

Application April 15, 1953, Serial No. 349,012

6 Claims. (Cl. 343-812) This invention relates to television antennas, and has for its principal object the provision of improvements in the antenna disclosed in the copending application of Leonard J. Lynch, Serial No. 215,332, filed March 13, 1951, now Patent No. 2,776,430 issued Jan. 1, 1957.

In the copending application mentioned, the antenna disclosed consists of two groups of three horizontally disposed, vertically spaced, parallel, metal rods mounted in coplanar relationship on opposite sides of a vertical supporting-mast by means of suitable insulators, with a vertical metal rod on each side of the mast electrically connecting the mid-points of the horizontal rods of each group. The inner end of the middle rod of each group is cross-connected electrically with the inner ends of the upper and lower rods of the other group and a lead-in wire to the receiving set is' electrically connected to the inner ends of these middle rods to connect the antenna with the set. The antenna has cooperating with it a reflector disposed in spaced parallel relationship behind the antenna and arranged to be turned with it so that the antenna faces the selected station and the reflector shields the antenna against interference from another station on the same channel. The reflector consists of two sets of five horizontal parallel metal rods disposed in equally vertically spaced coplanar relationship on opposite sides of a supporting mast, the rods of each set rigidly electrically connected at opposite ends by vertical rods and supported on the mast in insulated relationship to one another and to the mast. The five rods in each set connected as described form four loops on each side of the mast, and any combination of loops can be used in the tuning of the reflector to provide good reception in the various channels. The reflector is placed as close as possible to the antenna to prevent as much interference as possible from the side and yet allow maximum gain on the high band.

The reflector, in other words, may be considered as an element placed in a horizontal plane behind a dipole of the proper length and at the proper spacing to permit forward gain. This gain results from waves inducing a current in the reflector element and radiating back to the dipole in phase with the incoming signal. This is commonly referred to as a regenerative eflect and is utilized in a novel manner by virtue of a change in the construction of the antenna proper, in accordance with our invention, whereby the antenna-reflector combination is designed to fit the needs of any area whether it be a gain on all channels concerned, or be a need for elimination or reduction of co-channel or interchannel interference.

The invention is illustrated in the accompanying drawing, in which- Fig. 1 is a perspective view of our improved antenna, the same being shown without the reflector;

Fig. 2 is a face view of the reflector, which is the same as that disclosed in the copending application;

Fig. 3 is a perspective view of the antenna-reflector Patented Jan. 20, 1959 assembly, the reflector being a unit purchasable separately and combinable with existing antennas, and

Figs. 4 to 6 are diagrams used in describing the operation.

The same reference numerals are applied to corresponding parts in these views.

Referring first to Fig. l, the antenna comprises a vertical supporting mast 11, having two sets of horizontally disposed, vertically spaced, parallel, metal rods 12, 13, and 14, and 12', 13 and 14 mounted in coplanar relationship but on opposite sides of the mast 11, as by means of insulators 15 to which the rods or elements are suitably secured in insulated relation to one another and to the mast. A verticalmetal rod 16 connects the midpoints of only rods 12 and 14 in rigid relationship, and another vertical metal rod 17 connects the midpoints of only rods 12 and 14' in rigid relationship, rods 13 and 13' being insulated from rods 16 and 17, as indicated at 18 and 18. The inner ends of the middle rods 13 and 13' are cross-connected with the upper and lower rods 12 and 14 and 12' and 14' by conductors 19 to complete the antenna, and there is a conducting line 20 connected therewith and extending to the set. The antenna as thus far described has the general appearance of a fly swatter and is often so named.

Referring next to Fig. 2, the reflector consists of two sets of horizontal, parallel, metal rods 2125 and 2125 disposed in vertically spaced coplanar relationship on opposite sides of a supporting mast 26, the rods of each set being rigidly electrically connected by vertical rods 27 and 28 at their inner and outer ends, respec tively, and supported on the mast 26 by insulators 29 in insulated relation to one another and to the mast. The vertical array of rods 21, 23, and 25 and 21', 23, and 25 in the reflector is similar to the vertical array of rods 12-14 and 1214 on the antenna, the rods 22 and 24 and 22' and 24 in the reflector being midway between rods 21, 23, and 25, and 21, 23, and 25', respectively. The reflector is mounted behind the antenna, as shown in Fig. 3, in a fixed, spaced, parallel, relationship, the masts 11 and 26 being cut off just below the antenna and reflector and clamped together, as shown at 30, and to a main mast 31, which is, of course, arranged to be turned in the usual way, so that the antenna portion faces the selected station and the reflector portion shields the antenna portion against interference from another station on the same channel. Four loops are formed on each side of the mast 26 by the interconnected rods, and shorting bars 32, which are disposed between the ends of the rods 21-25 and 2125, are adapted to connect any combination of loops permanently, or, as disclosed in the copending application, these bars 32 may be normally in spaced disconnected relation to the rods and form the armature parts of relays arranged to be selectively energized by manual operation of selector switches to use any combination of loops in the tuning of the reflector for good reception of programs in any channel. Thus, some of the channels require actuation of as many as four bars 32 at a time, while others require the operation of only two bars. in many installations, however, and this is true especially in fringe areas where the only available good reception is from one direction, the bars 32 may be fixed permanently to provide a given combination of loops found to give the best results, and'in some of these installations one or more of the rods 2125 and 2125' may be omitted if not needed for the loop combination selected.

In order to understand the operation, the diagrams Figs. 4-6 will be referred to. Consider first two dipoles like rods 13-14 and 13'14, as illustrated in Fig-5, placed one above the other, one-half wave, length apart.

3 These dipoles are cut for full wave length on the high band and cross-connected by wires 19, and the incoming signal indicated by the voltage curves X strike the dipoles at the same instant so that the electrical charge on each element will be in the same phase, voltage and current. If the energy radiated from one dipole travelled through the air to the other dipole, it would arrive out of phase and the charge would be zero, but that is not true here, because the wires 19 crossconnecting the dipoles carry the R. F. voltage and current and add the charges in phase. Carrying this a step further, consider next that another dipole 1212' is added, and it is evident that it, being also a half-wave length away from the middle dipole 13-13, adds its signal charge. The gain of this antenna has been measured and amounts to 12 db. The operation thus far has dealt only with the high band, namely, channels 7-13, with each of these channels at a particular wave length. The low band, channels 26, are received without interfering with the gain of the high band. It will be noticed in Fig. 5 that the voltage curves X are alike and that they cross each dipole one-half way from the middle of each dipole. This point has substantially zero voltage and therefore the two elements 12 and 14 can be tied together at their mid points by rod 16 and the two elements 12 and 14 can be tied together at their mid points by rod 17, as shown in Fig. 4, skipping the mid-points of the dipole 13-13, as indicated at 1818, without any harm to the antenna, and, at the same time, give a better impedance match to the transmission line. Fig. 6 illustrates diagrammatically the electrical effect which this novel tie-up obtains on the low band. The heavy lines indicate that part of one side, namely 13, enters into the operation of the opposite side of the antenna. As a result, a signal striking the one side of the middle dipole is fed through the wires 19 to the other side of the outer dipoles and radiated to add to the signal on the middle dipole, thereby giving a regenerative effect capable of building up on a very weak signal. It is possible that one wave striking the antenna may be used to reinforce several subsequent waves, whereas it is known that only one rein forcing action is obtainable with an in-line antenna.

The reflector placed behind the improved antenna operates as described in the copending application to:

(1) Permit gain on desired channels;

(2) Reject interference from the rear of the antenna, and

(3) Permit a combination of rejection of interference and gain on channels concerned.

It is believed the foregoing description conveys a good understanding of the objects and advantages of our invention. The appended claims have been drawn to cover all legitimate modifications and adaptations.

We claim:

1. An antenna suitable for television use comprising an upright supporting mast, three pairs of substantially horizontal metallic rod elements carried by said mast in insulated relation thereto and to one another and extending from opposite sides of the mast in aligned relationship, the pairs being in evenly vertically spaced substantially coplanar relationship, and a substantially vertical metallic rod element on each side of the mast rigidly interconnecting the three rod elements together at their midpoints but so as to electrically connect the midpoints of the top and bottom rod elements through said vertical rod element while leaving the middle rod element in insulated relationship to the vertical rod element, each pair of aligned horizontal rod elements being electrically cross-connected with the next pair of aligned horizontal rod elements.

2. An antenna suitable for television use as set forth in claim 1 wherein said pairs of horizontal rod elements are spaced a half-wave length, and each pair measures one wave length from end to end thereof.

3. An antenna suitable for television use comprising an upright supporting mast, more than two pairs of substantially horizontal metallic rod elements carried by said mast in insulated relation thereto and to one an other and extending from opposite sides of the mast in aligned relationship, the pairs being in evenly vertically spaced, substantially coplanar relationship, and a substantially vertical metallic rod element on each side of the mast rigidly interconnecting the midpoints of said horizontal rod elements but so as to electrically connect the midpoints of only alternate ones of said horizontal rod elements while leaving the horizontal rod element therebetween in insulated relationship to the vertical rod element, each pair of aligned horizontal rod elements being electrically cross-connected with the next pair of aligned horizontal rod elements.

4. An antenna suitable for television use as set forth in claim 3, wherein said pairs of horizontal rod elements are spaced a half-wave length, and each pair measures one wave length from end to end thereof.

5. A television antenna and reflector combination comprising an antenna consisting of an upright supporting mast, more than two pairs of substantially horizontal metallic rod elements carried by said mast in insulated relation thereto and to one another and extending from opposite sides thereof in aligned relationship, the pairs being in evenly vertically spaced substantially coplanar relation, and a substantially vertical metallic rod element on each side of the mast rigidly interconnecting the horizontal rod elements at their midpoints but so as to electrically connect the inidpoints of alternate rod clements while leaving the horizontal rod element therebetween in insulated relationship to the vertical rod element, each pair of horizontal rod elements being electrically cross-connected with the next pair of horizontal rod elements, said antenna being mounted in a fixed, spaced, substantially parallel relation to a reflector, said reflector comprising an upright supporting mast, pairs of substantially horizontal metallic rod elements carried by said mast in insulated relation thereto and to one another extending from opposite sides thereof in aligned relationship, the pairs being in vertically spaced substantially coplanar relation, a pair of substantially vertical metallic rod elements in substantially parallel spaced relation on each side of the mast rigidly and electrically intercom necting the end portions of the horizontal rod elements so as to define a plurality of loops on each side of the mast, and means electrically connecting loops on opposite sides of the mast, said last mentioned means being constructed and arranged to electrically connect a selected one or more loops on one side of the mast with a selected one or more loops on the other side.

6. A television antenna and reflector combination comprising an antenna consisting of: an upright supporting mast, more than two pairs of substantially horizontal metallic rod elements carried by said mast in insulated relation thereto and to one another and extending from opposite sides thereof in aligned relationship, the pairs being in evenly vertically spaced substantially coplanar relation, and a substantially vertical metallic rod element on each side of the mast rigidly interconnecting the horizontal rod elements at their midpoints but so as to electrically connect the midpoints of alternate rod elements while leaving the horizontal rod element therebetween in insulated relationship to the vertical rod eiement, each pair of horizontal rod elements being electrically cross-connected with the next pair of horizontal rod elements, said antenna having three pairs of horizontal rod elements in evenly vertically spaced relation and being mounted in a fixed, spaced, substantially parallel relation to a reflector, said reflector having five pairs of horizontal rod elements in evenly vertically spaced parallel relation, the first, third and fifth pairs of the latter rod elements being spaced like the three pairs of rod elements of the antenna, and the second and fourth pairs of rod elements of the reflector being mid- 5 way between the first and third and third and fifth pairs, respectively, a pair of substantially vertical metallic rod elements in substantially parallel spaced relation on each side of the mast rigidly and electrically interconnecting the end portions of the horizontal rod elements so as to define a plurality of loops on each side of the mast, and means electrically connecting loops on opposite sides of the mast, the said means electrically connecting loops on opposite sides of the mast of said reflector being leeted one or more loops on one side of the mast with a selected one or more loops on the other side.

References Cited in the file of this patent constructed and arranged to electrically connect a se- 10 2,558,727

UNITED STATES PATENTS Gothe Sept. 22, 1936 Von Radinger June 27, 1939 Posthumus June 18, 1940 Bernet July 3, 1951

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2055100 *Sep 25, 1933Sep 22, 1936Telefunken GmbhShort wave antenna
US2163770 *Feb 26, 1936Jun 27, 1939Telefunken GmbhAntenna
US2205174 *Dec 20, 1938Jun 18, 1940Rca CorpDirectional antenna system
US2558727 *Jul 1, 1942Jul 3, 1951Bernet Edwin JAntenna
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5146233 *Jun 6, 1990Sep 8, 1992Thomson-CsfRotating antenna with dipoles for hf waves
Classifications
U.S. Classification343/812
International ClassificationH01Q21/12, H01Q21/08
Cooperative ClassificationH01Q21/12
European ClassificationH01Q21/12