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Publication numberUS2359620 A
Publication typeGrant
Publication dateOct 3, 1944
Filing dateJun 13, 1942
Priority dateJun 13, 1942
Publication numberUS 2359620 A, US 2359620A, US-A-2359620, US2359620 A, US2359620A
InventorsCarter Philip S
Original AssigneeRca Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Short wave antenna
US 2359620 A
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Description  (OCR text may contain errors)

Oct. 3, 1944. Rs. CARTER SHORT WAVE ANTENNA Filed June 13, 1942 wmmmu M65 3; mo 35 3 witQw INVENTOR Z CARTER. 7/6

ATTO R N EY Patented Oct. 3, 1944 SHORT WAVE ANTENNA Philip S. Carter, Rocky Point, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application June 13, 1942, Serial No. 446,873

3 Claims.

The present invention relates to short wave antennas and has for its primary object the provision of a short wave antenna which presents a negligible reactance at its terminals over a wide range frequency such as may be required in television transmission or reception. When a wide band of frequencies is used, as in the transmission of television programs, it is desirable that the antenna act as a substantially pure resistance of substantially constant magnitude over a wide range of frequencies in order to prevent the occurrence of standing waves along the feeder. The standing waves are an indication of reflection of energy back into the transmission line from the antenna. Such reflections cause variations in the input impedance of the transmission line and increased losses in the transmission line.

The present invention provides a highly desirable type of short wave antenna for use over a wide frequency range, the antenna causing very little reactance variation in the transmission line with a variation in frequency.

In principle, the antenna of the present invention comprises a pair of conducting surfaces in the form of flat discs arranged coaxially and in parallel planes. The discs are preferably energized at the centers of their facing surfaces. The radii of the conducting plates and the diameter of the conductors to which the transmission line conductors are connected are so proportioned with respect to the wavelength to be employed that a broad frequency characteristic is attained,

The present invention will be more fully understood by reference to the following detailed description which is accompanied by a drawing in which Figure 1 illustrates an embodiment of the present invention, Figure 2 illustrates a modification of the form shown in Figure 1, and Figure 3 illustrates by means of curves some of the features of the present invention.

The antenna shown in Figure 1 is composed of a pair of flat circular plates I and I2 coaxially disposed in parallel planes. In the particular embodiment disclosed, the radius of the plates I0 and I2, is chosen as .1103 where i is the operating wavelength of the antennas, in one particular case, 150 centimeters. In the particular embodiment shown the axis of the antenna may be assumed to be vertical for radiating uniformly in a horizontal plane. Of course, if horizontally polarized radiation and some horizontal directivity is desired, the axis may be horizontally arranged. The antenna is coupled to a frequency transducer means (not shown), such as a radio transmitter, by means of transmission line TL having its conductors connected to the centers of plates ill and I2 through intermediary conductors II and l3 of somewhat larger diameter than the diameter of the conductors of the transmission line. In the particular example embodiment mentioned above, the diameter of conductors H and I3 was chosen as .25 centimeter.

The modification shown in Figure 2 is similar to that shown in Figure 1, with the exception that the transmission line TL is, in this modification, a concentric line having its central concluctor l4 connected to conductor H and passing through a hollow conductor l3. The casing l5 of the transmission line forms an extension of conductor l3 below the plate [2. This embodiment has some advantages over that shown in Figure 1 because the structure is entirely symmetrical, the transmission line leading away from the antenna along its vertical axis of symmetry. Thus, any disturbance of the radiated field pattern by the transmission line is avoided.

The curves shown in Figure 3 illustrate the variations in voltage and current along the surface of plates Ill and I2 with varying distance r from the center, as indicated by the point I6 in Figure 1. The curves in Figure 3 plot voltage and current against varying values of r/x where r is the radial distance between the center of plate In and point 16.

While I have particularly shown and described several modifications of my invention, it is to be distinctly understood that my invention is not limited thereto but that improvements within the scope of the invention may be made.

I claim:

1. A short wave antenna including a pair of flat conductive plates coaxially arranged in parallel planes and a, two conductor substantially aperiodic transmission line and means for coupling said transmission line to said plates at substantially the midpoints of their facing surfaces, said means including a pair of coaxially arranged conductors, each connected at one end to the midpoints of one of said plates, the other ends of said conductors being connected to the conductors of said-transmission line, the dimensions of said plates and said conductors being so proportioned that over a broad frequency band said antenna appears to said transmission line as a substantially pure resistance of substantially constant magnitude.

2. A short wave antenna including a pair of flat conductive plates coaxially arranged in parallel planes and a coaxial transmission line having an inner conductor and an outer shell, said shell being connected to and extending through one of said plates at its center, said inner conductor being connected to the center of the other of said plates through a short section of conductor having a diameter substantially equal to that of said outer shell, the dimensions of said plates and said conductors being so proportioned that a broad frequency band is obtained.

3. A short wave antenna including a pair of flat conductive plates coaxially arranged in parallel planes and a coaxial transmission line having an inner conductor and an outer shell, said

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2519209 *Mar 30, 1945Aug 15, 1950Hazeltine Research IncAntenna
US2532919 *Aug 13, 1948Dec 5, 1950Arthur Johnson WilliamRadio aerial system, and particularly directive aerial system
US2541037 *Apr 19, 1946Feb 13, 1951Standard Telephones Cables LtdAntenna
US2566491 *Mar 15, 1946Sep 4, 1951Belmont Radio CorpAntenna construction
US2567220 *Oct 29, 1947Sep 11, 1951Sperry CorpScalloped limacon pattern antenna
US2636123 *Sep 17, 1945Apr 21, 1953Hanley Thure EElectromagnetic shielding apparatus
US2774967 *Nov 19, 1949Dec 18, 1956Int Standard Electric CorpBalanced doublet antenna of small dimension
US2939143 *Oct 4, 1954May 31, 1960Sadir CarpentierWide band dipole antenna
US3432858 *Dec 14, 1964Mar 11, 1969Brown Allan RShort dipole antenna
US3568206 *Feb 15, 1968Mar 2, 1971Northrop CorpTransmission line loaded annular slot antenna
US3827053 *Feb 28, 1972Jul 30, 1974Volkers DAntenna with large capacitive termination and low noise input circuit
US4342037 *Aug 22, 1980Jul 27, 1982The Boeing CompanyDecoupling means for monopole antennas and the like
US4675691 *May 23, 1985Jun 23, 1987Moore Richard LSplit curved plate antenna
US5347291 *Jun 29, 1993Sep 13, 1994Moore Richard LCapacitive-type, electrically short, broadband antenna and coupling systems
DE4310532A1 *Mar 31, 1993Oct 6, 1994Rohde & SchwarzPush-pull amplifier for an active dipole antenna
EP1391009A1 *Apr 12, 2001Feb 25, 2004Gregory Daniel HallPlate dipole antenna
WO1982000735A1 *Aug 20, 1981Mar 4, 1982Boeing CoDecoupling means for monopole antennas and the like
WO1989007348A1 *Jan 27, 1989Aug 10, 1989Maurice Clifford HatelyRadio antennas
Classifications
U.S. Classification343/792, 343/795
International ClassificationH01Q9/28, H01Q9/04
Cooperative ClassificationH01Q9/28
European ClassificationH01Q9/28