US2657312A

US2657312A - Radio and television antenna

Info

Publication number: US2657312A
Application number: US248697A
Authority: US
Inventors: Saranga Cesare
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-09-28
Filing date: 1951-09-28
Publication date: 1953-10-27
Anticipated expiration: 1970-10-27

Description

Oct. Z7, 1953 c. SARANIGA. 2,657,312

RADIO AND TELEVISION ANTENNA Filed Sept. 28, 1951 INVENTOR BY yew/9mm A0 ATTORNEYS.

Patented Oct. 27, 1953 UNITED sir-Ares PATENT OFFICE RADIO AND TELEVISION ANTENNA Q sa e Strange w lio he ls Y, Application September 28, 1951, Serial No, 248,697 ql nn: (C1. ZQ= 33 This invention relates to antennas, and more particularly to an indoor television antenna. The main object of the invention is to provide a novel and improved antenna suitable for use with television and other relatively high frequency radio receivers, the improved antenna be.- ing'simple in construction, being relatively compact in size, and being substantially omnidirectional. r

A further object of the invention is to provide an improved indoor antenna particularly suit.- able for use with television receivers, said antenna being arranged to function satisfactorily on both the low frequency and high frequency television bands, providing a reduction in interference, being substantially omnidirectional, whereby it is ordinarily not necessary to rotate the antenna to receive a television signal with satisfactory intensity, being inexpensive to manufacture, and being attractive in appearance.

A still further object of the invention is to provide an improved indoor television antenna which is arranged to provide substantially bale anced performance on both the high frequency and low frequency television bands, the antenna involving only simple, inexpensively fabricated parts, being sturdy in construction, and being arranged to provide satisfactory reception of all television channels without requiring the an tenna, in most cases, to be especially oriented to eceive any particular channel.

Further objects and advantages of the invention will become apparent. from the following description and claims, and from the accompany: ing drawings, wherein:

Figure 1 is a perspective view of an improved radio and television antenna constructed in ac-. cordance with the present invention.

Figure 2 is a vertical cross sectional view taken enthrline. 3:? of Fi ure 1.

Figure is a Vertical cross sectional view taken 9%. the ine 3:13 of Figure 1.

' Figure 4 is a schematic wiring diagram showce the electri al connections of the various elements or the antenna of Figures 1 to 3.

geferlin to, the drawings, the complete an.-

' antenna assembly comprises a base I2 comprising; the mating elements I3 and I4 of insulat- Qi i elr T s lement I3 hasv an upstand- PLg. 5 75115 c reular inte ral portion l5 and or elemen 1 upstanding, generally tiller nte ral portion it, the portions and I6 heirs waited to ether by a. transverse bolt n, as

shown Figure g, whoa the elements I3 and 2 I4 are clamped together by the bolt II, it will be seen that a hollow space is defined under the member I2, said hollow space including the cavity defined between the opposing inclined circular upstanding elements I5 and I6.

Molded in the respective elements I3 and I4 adjacent the base portions of the upstanding elements I5 and I6 are the lower ends of respective upwardly projecting, substantially semicircular arms [8 and I9, said arms I8 and I9 being formed irom suitable conductive rod material, as for example from metal tubing, the semicircular arms IB and I9 being arranged in coplanar relation and being rigidly connected together at their top ends by an arcuate connecting bar 20 of insulatingmaterial. As shown in Figure 3, with the arms I8 and I9 connected, said arms def newith the insulating bar 20 a substantially circular loop of relatively large diameter having the insulating 'bar 20 located at its top ends.

Rig-idly secured to the upper portions of the respective arms I8 and I9 are the respective pairs of conductive stubs 2| and 22 and 23 and 24, As shown in Figure 3, said conductive stubs 2|, 22 and 23, 24 extend upwardly and outwardly from the respective arms I8 and I9 on opposite sides of the base I2, the arms 2| and 22 being spaced apart on the arm I8 and the arms 23 and '24 being spaced apart on the arm I 9 in the manner shown in Figure 3, the arms 2| adn 23 being relatively short as compared with the arms 22; and 24.

The circular loop defined by the arms I8 and I9 preferably has a diameter of the order of at least 12 inches, the

arms

22 and 24 being 'gf a length of approximately 18 inche andth arms El and 23 being of a length of approximately 3 inches. The length of the insulating bar 20 is approximately 1%; inches, and the ends of said insulating bar may bev secured to the top ends of arms I8 and I9 by being frictionally engaged in the top ends of said arms.

Designated at 25 and 26 are respective terminals secured in the horizontal portions of the base section I3 and I4, the respective lower ends of the arms I8 and I9 being connected by short wires 2! and 28 to the

respective terminals

25 and 26. I

Designated at 29 is a circular loop of conductive rod material, such as metal tubing, whose iower ends are rigidly clamped between the upper portion of the insulating disc elements I5 and I6, rigidly securing the loop 29 in the meeting plane between base sections I3 and I4, said meeting plane extending at right angles to the vertical plane defined by the arms I8 and I9.

The loop 29 is thus contained within the circular loop defined by arms [8 and i9 and the top connecting bar 29, the loop 29 being relatively small in diameter as compared with the circular loop defined by elements I8, [9 and 2%, For example, the loop 29 may be approximately six inches in diameter. As shown in Figure 1, loop 29 extends in a vertical transverse plane which intersects the vertical plane defined by elements I8, l9 and at right angles and at the vertical center line of the antenna assembly.

Disposed in the upper portion of the cavity defined between the opposing circular elements l5 and i6 is a capacitor 33 having a capacitance of about .002 mf. which is connected between the ends of the inner loop 29, as shown in Figure 4. Designated at 3! is another capacitor which is disposed in the cavity between disc elements i5 and 56, said capacitor being connected between one end of the loop 29 and the lower end of the semicircular arm l9. Capacitor 3i has a capacitance of approximately .01 mf.

It will thus be seen that the arms 18 and it are connected respectively to the terminals and 26 and may be considered as the respective elements of a dipole array having an electrical length approximately that required to resonate to the center of the lower television frequency band, whereas the loop 29 may be considered as an unbalanced signal collector having electrical characteristics which apparently cause the loop v29 to be resonant to frequencies in the upper television band. The relatively large capacitor 31 couples the loop 29 to the antenna terminal 26 and the capacitor 3E3 provides a compensating effect to improve the matching of the antenna to the transmission line 32 and 3B connecting the antenna terminal to a television receiver, such as the receiver shown at 34. The

lines

32 and 33 are preferably the conductors of conventional 300 ohm twin lead transmission line, and the length of the transmission line is preferably of the order of six feet.

While the exact theory of operation of the antenna array above described is not entirely clear, it is believed that the loop 29 and capacitor 30, together with the distributed capacitance to ground of loop 25 defines a band pass filter for the low frequency television signals while at the same time serving efficiently as a signal collector for the high frequency television signals. It is further believed that the semicircular arms I8 and I9, together with their distributed capacitance to ground define a band pass filter for the high frequency television signals as well as serving as an efficient dipole array for the low frequency television signals, the dipo1e effect being reinforced and augmented by the respective pairs of

stubs

2i and 22, and 23, 24 provided on the respective dipole arms I8 and 19. The combination of the characteristics above described apparently results in an over-all array which is substantially omnidirectional and which is subthe orientation of the antenna after it has been 4 once positioned adjacent to the television receiver with which it is to be employed.

While a specific embodiment of an improved radio and television antenna has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. An antenna of the character described comprising an insulating base, a pair of coplanar rigid conductive arms, insulated from each other, secured to said base and projecting upwardly therefrom on opposite sides of said base, a rigid conductive loop secured to said base between said arms in a vertical plane at a substantial angle to the plane of said arms, and means capacitively coupling said loop to one of said arms.

2. An antenna of the character described comprising an insulating base, a pair of coplanar rigid conductive arms, insulated from each other, secured to said base and projecting upwardly therefrom on opposite sides of said base, a rigid conductive loop secured to said base between said arms in a plane at a substantial angle to the plane of said arms, means coupling said loop to the lower end of one of said arms, and a pair of terminals connected respectively to the lower ends of said arms.

3. An antenna of the character described comprising an insulating base, a pair of rigid coplanar conductive arms, insulated from each other, secured to said base and projecting upwardly therefrom on opposite sides of said base, a rigid conductive loop secured to said base between said arms in a vertical plane at right angles to the plane of said arms, and means capacitively coupling said loop to one of said arms.

4. An antenna of the character described comprising an insulating base, a pair of rigid coplanar opposing arcuate conductive arms, insulated from each other, secured to said base and projecting upwardly therefrom on opposite sides of said base, a rigid circular conductive loop of much smaller radius than said arm secured to said base between said arms in a vertical plane at right angles to the plane of said arms, and means capacitively coupling said loop to the end of one of said arms.

5. An antenna of the character described comprising an insulating base, a pair of rigid coplanar opposing arcuate conductive arm secured to said base and projecting upwardly therefrom on opposite sides of said base, a rigid circular conductive loop of much smaller radius than said arms secured to said base between said arms in a vertical plane at right angles to the plane of said arms, a capacitance connected in said loop, and means capacitively coupling one end of said loop to one of said arms.

6. An antenna of the character described comprising an insulating base, a pair of rigid coplanar opposing arcuate conductive arms secured to said base and projecting upwardly therefrom on opposite sides of said base, an insulating bar rigidly connecting the top ends of said arms, a rigid circular conductive loop of much smaller radius than said arms secured to said base between said arms in a vertical plane at right angles to the plane of said arms, a capacitance connected in said loop, and means capacitively coupling said loop to the lower end of one of said arms.-

7. An antenna of the character described comprising an insulating base, a pair of rigid coplanar, opposing, arcuate conductive arms secured to said base and projecting upwardly therefrom on opposite sides of said base, an insulating bar rigidly connecting the top ends of said arms, respective, relatively short conductive bars rigidly secured to said arms and projecting upwardly and outwardly from said arms in the same plane therewith, a rigid circular conductive loop of much smaller radius than said arms secured to said base between said arms in a vertical plane at right angles to the plane of said arms, a capacitance connected in said loop, and means capacitively coupling one end of said loop to the lower end of one of said arms.

8. An antenna of the character described comprising a base of insulating material, respective opposing semicircular conductive arms secured rigidly to said base and projecting upwardly therefrom in a common vertical plane, an insulating bar rigidly connecting the top ends of said arms, a plurality of relatively short, straight, spaced conductive bars secured to each arm and projecting upwardly and outwardly therefrom in the same plane as said arms, said conductive bars being of different lengths, a rigid circular conductive loop secured to said base in a vertical plane at right angles to the plane of said arms, a capacitance in said base connected between the ends of said loop, another capacitance in said base connecting one end of said loop to the bottom end of one of said arms, and a pair of output terminals connected respectively to the bottom ends of said arms.

9. An antenna of the character described comprising a base of insulating material, respective opposing semicircular conductor arms secured rigidly to said base and projecting upwardly therefrom in a common vertical plane, an insulating bar rigidly connecting the top ends of said arms a plurality of relatively short, straight, spaced conductive bars secured to the upper portion of each arm and projecting upwardly and outwardly therefrom in the same plane as said arms, said conductive bars being of different lengths, a rigid circular conductive loop secured to said base in a vertical plane at right angles to the plane of said arms, said loop being of much smaller radius than said arms, a capacitance in said base connected between the ends of said loop, another capacitance in said base connecting one end of said loop to the bottom end of one of said arms, and a pair of output terminals connected respectively to the bottom ends of said arms.

CESARE SARANGA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,924,408 Leib Aug. 29, 1933 1,947,021 Roberts Feb. 13, 1934 2,291,450 Case July 28, 1939 2,541,107 Selgin Feb. 13, 1951 FOREIGN PATENTS Number Country Date 982,724 France Jan. 31, 1951