US2518297A - High-frequency antenna - Google Patents

Description

-Au. 390 M. D. ERcouNo HIGH FREQUENCY ANTENNA 2 Sheets-Sheetl Filed Dec. 27, 1948 INVENTOR. Mama H [Rwy/v0 A T TOR/VA V Aligo 8, 1 956 M. ERCOLRNO 5 9 HIGH FREQUENCY ANTENNA Filed Dec. 27, 1948 2 Sheets-Sheet 2 Men/A54 7. [mi //v0 ATTORNEY Patented Aug.

- andother high frequency systems.

arrangement.

. I UNITED Rel S30 9] I .v 5B"-233.-4, stares PATENT OFFICE-1A I man-sarcomas! mm I Ereolino ,Wanamassa ,N.-J.

. .mlieation-DeoemberZ'LlQiQSer-hllio. rm;

This invention relates use and more particularly to antennas generally employed for television, frequency modulation The efllclency of a conventional dipole antenna is well understood as is its action at frequencies other than for which it is designed. Briefly, a

"dipole designed. for one frequency will operate at reduced eillciency when'operated at diiiering frequencies. In the event of higher frequencies,

the effect is due to flattening out of the radiation lobes so that although more wire or metal is being energized, the effective radiation of the antenna inany one directionisless;

The present invention provides a dipole antenna wherein a pair of dipole rods are tilted forward so that flattening of the lobes is prevented. Substantially all the energy becomes additive and in phase, the lobe sharpening and remaining in line for aconsiderable frequency range. The antenna is vout to the lowest frequency of a wide range of -frequencies to beaccommodated. At higher frequencies it becomes continuously more eflective than a half wave 'until, at the highest channel frequency to be received, it may function as a full wave antenna on each dipole rod with practically the same pattern as'at its lower frequencies. Accordingly. the 1 voltage derived at such higher frequencies is more eii'ective. The antenna, with its dipolestilted forward, is particularly efllcient when in the form of crossed dipoleswhich simulate the action of, solidly spun come without involving the bulk of such cones. It will be recognized that the eflect thereof is to render the center impedance substantially-constant.

In providing the antenna of the instant invention, I have further devised a bracket system which extremely facilitates the assembly and installation of the antenna with the dipoles prgperly' positioned and automatically-given the re quired forward lean or tilt. I p

The above and other advantages and objects of my invention will be further understood from the following description and drawings in which:

' Fig. 1 is a perspective view of one form of the improved antenna as installed for, operation- Fig. 2 is a partly broken away top view thereof. Fig. 3 is a fragmentary, enlarged view of the bent bracket resulting in the tilted dipole Fig.4isarcarviewof Fig.8.

Fig. 5 is an enlarged cross-sectional view alon the line H of Pig. 8.

- scan". (on. est-sass) m. s a a graphical view illustrating the lobe u patterns obtained by antennaof my design at widelyvaryingfreqnencies. v

The invention is illustrated in connection with a crossed dipole front element and a similar reflector element s I to the; desired degree: However, .the inventionv is applicable to other forms of.dipole arrangements, such u folded-or single dipoles or thelike. Y I I In the form shown, the antennacomprises a cross beam II to which is connected an end member Ii supporting an insulatiomblock if. It is on this insulation block that the dipoles-are effectively mounted although it is evident that any conventional arrangement may be employed in place of that described. Outer bracket member i3 is secured by bolts or screws it to block I2. .Bracket'member it is bent along a line it so that it is caused to be forwardly tilted in relation erally maintain a suitably spaced relationship between the bracket members. p Y Bracket member is is shown as substantially triangular theedges thereof defining an angle of approximately 45 degrees. The outer margins or legs 18 and It of the triangle are shaped so as to be concavo-convex. The margins or legs 20 and 2| of member l are similarly formed so that, complementing the shape of margins l8 and ,j l, a pair of angularly related channels 22 and 23 are formed when the bracket members are engaged. To the other side'of insulation block l2 are connected the brackets 25 and 26 which duplicate, in form and function, the bracket previously described. I

In the formed margin channels of each bracket are inserted and maintained the front dipole rods 21 which automatically assume the proper crossangle and tilt as provided by the bending of the top bracket members as well as by the channels 22 and 23 formed by the engaged members.

In the form shown.'the antenna is provided with a straight reflector system spaced from the front dipoles by the length of beam il.- Thus, end member 3. supports the outer one-piece bracket member ll which has angular extremities duplicating those illustrated in Fig. 3 but being integralinstead of being separated by insulation.

'rwo inner bracket members 32 and 22 are connected as by bolts 34 to the respective angular extremities of reflector bracket 3 I The angularly set channels 35 and it at one end of the reflector bracket provide positioning means for dipole rods 31, while the other end of the reflector. bracket does the same for the opposite dipole rods.

In order to mount the antenna described to a mast, any conventional means may be employed. Thus, a U-shaped clamp 40 has its legs brought through beam Ill and fastened as by nuts 4|. An opposing clamp member 42 clamps, in combination with U-shaped clamp 40, the mast 43 when the nuts 4| are tightened. Such an arrangement is, of course, more or less conventioned and may be supplanted by various other mast arranging means. 1

The assembly and installation of the antenna described is rendered most convenient and simple through the bracket construction set forth. Thus, rods 21 which may, if desired, be in the form of aluminum tubing or the like, are simply inserted in the channels 22 and 23 whereupon the bolts I1 are tightened so as to reduce the size of the channel and firmly grip the rods. In this way, the V-shaped disposition of the rodsis automatically achieved and maintained. Further,

and as is considered of importance, they are automatically given the desired forward tilt by virtue of the pre-formed bend I5. The front dipole rods having been inserted and clamped, those of the rear or reflector portion may be similarly ap-.

plied. All of the dipole rods may be of the same form so as to economize ,on manufacturin ex penses and facilitate site assembly of the an tenna.

In the form shown, the desired forward tilt is effected by the angular relationship of the elongated dipole rods 21, the angle of which may be in the order of 140 degrees or the like although considerable deviation from such angle is permissible without deviating from the advantages of the invention. Referring to Fig. 6, there are shown lobe patterns obtained over a band of frequencies when employing an antenna constructed according to the instant invention. The solid line pattern 50 shows the response of the antenna at 60 megacycles. 'I'he' brokenline pat tern shows a response at I megacycles while the small dash line pattern 52 shows the response at 215 megacycles. dipole ,at the 60 megacycle frequency. It will be observed that, all the lobes are in substantial alignmentand that the front to back ratio is extrerhely favorable.

When a single dipole is used, the axis of elon-' gation of the rods will be in the same horizontal, plane. 'When the crossed .or V dipole arrangement is used, as illustrated in Figs. 3 and 4, the apices of each V formed by the dipoles of each bracket will be substantially adjacent the V dipole structure of the opposite bracket. Further, as shown, the axis of each V structure will be in substantially the same horizontal plane.

The brackets are shown as being formedv with central openings 53. These are considered of value in that the antenna offers less wind resist-, ance when secured to a mast so that the stability of the structure is enhanced.

The length of beam Ill is such as to maintain approximately one-quarter wave lengths spacing between the front dipole structures and the reflectors as is well known in the-art. However, the antenna is used for broad band reception. Accordingly, the distance between the front di- The antenna was cut as a guano? poles and the reflectors effectively varies with frequency by virtue of the straight disposition of the reflector dipole structures.

While there has been shown what at presentis considered a preferred embodiment of the invention, it will be evident that many changes and modifications may be made therein without 'departing from its spirit. It is therefore aimed in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.

What is claimed is:

1. A high frequency antenna comprising front and rear V-shaped antenna elements, said front antenna elements consisting solely of a. single pair of front V-shaped dipole structures, each dipole structure having its axis in a horizontal plane and the apices of the respective structures being substantially adjacent each other, an insulating member between said apices and to which the structures are connected, each of said front pair of V-shaped structures being inclined toward the other so that their axes form an obtuse angle, said rear V-shaped antenna elements consisting solely of a single rear pair of V-shaped dipole structures spaced from said front pair of dipole structures so as to act as reflectors therefor, the axes of said rear pair of V-shaped dipole structures being in a horizontal plane and in substantial alignment, the obtuse angle formed by said front pair of V-shaped structures axes, having its apex directed toward, and its arms directed away from, said rear pair of V-shaped structures.

2. A high frequency antenna according to claim 1 and including a pair of brackets fastened to said insulating member and to the respective front dipole structures, each of said brackets being bent along a vertical line so that said front dipole structures are maintained inclined toward each other by the bend in the brackets.

3. A high frequency antenna comprising front and rear V-shaped antenna elements, said front V-shaped antenna elements being composed of a single pair of crossed dipoles so as to form two front v-shaped dipole structures, each dipole structure having its axis in a horizontal plane and the apices of the respective structures being adjacent each other, each of said front pair of V-shaped-strllctures being inclined toward the other so that their axes form an obtuse angle, said rear V-shaped antenna elements being composed of a second pair of crossed dipoles so as to form two rear V-shaped dipole structures spaced II from said front pair of dipole structures so as to act as reflectors therefor, the axes of said rear pair of V-shaped dipole structures being in a horizontal plane and in substantial alignment, the obtuse angle formed by said front pair of V-shaped structures axes, having its apex directed toward, and its arms directed away from said rear pair of v-shaped structures.

MICHAEL D. ERCOLINO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,064,774 Wheeler Dec. 15, 1936 2,110,159 London et al Mar. 8, 1938 (Other references on following page) Number Name mu: roman PA'I'ENTS carter Number ----r---- 13:: 469,366 Great 311mm July 23, 1937 Lubcke Fen-24:19 5 530,114 Great Bntain Dec. 5, 1940 Scheldor! July 4, 1944 OTHER REFERENcEs at a] 291 1947 Radio's Master, twelfth Ed. United Catalog Jackson my 1949 Publishers, Inc., page 40, May 9, 1947, wintemu my 24,1949 Tale-Tech, May 1948, page 85.

Jul? 1949 10 Radio News, May 1945, pages 41 and 42.

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