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Publication numberUS2646549 A
Publication typeGrant
Publication dateJul 21, 1953
Filing dateJan 7, 1946
Priority dateJan 7, 1946
Publication numberUS 2646549 A, US 2646549A, US-A-2646549, US2646549 A, US2646549A
InventorsJohn Reed, Ragan George L
Original AssigneeUs Sec War
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Coaxial line terminating device
US 2646549 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

July 21, 1953 G. L. RAGAN ET AL i COAX'IAL LINE TERMINATING DEVICE 1 Filed Jan. 7, 1946 I INVENTORS WGEORGE L. RAGAN JOHN REED ATTORNFY Patented July 21, 1953 FENCE COAXIAL LINE TERMINATING DEVICE Application January '7, 1946, Serial No. 639,640

1 Claim.

This invention relates in general to electrical apparatus and more particularly to a means for terminating a coaxial line to enable dissipation of radio frequency energv passing therein.

In the development and testing of radio irequency equipment it is frequently desirable to provide a terminating impedance which may be connected at one end of a coaxial line to reflect the same impedance that an infinite line would reflect. It may also be desirable to dissipate the radio frequency energy in the form of heat to prevent it from radiating and producing interference with other radio frequenc apparatus.

A load or terminating impedance having the same characteristics as an infinite line would produce a standing wave ratio of unity, i. e. no reflections would be produced by said load.

It is an object of this invention to provide a novel apparatus for the dissipation of radio frequency energy It is a further object of this invention to provide a novel means for terminating or loading a coaxial line to enable dissipation of the R-F. energy with a minimum amount of reflections of said energy, thus making the standing wave ratio of the coaxial line substantially equal to unity.

Other objects, features and advantages of this invention will suggest themselves to those skilled in the art and will become apparent from the following description of the invention taken in connection with the accompanying drawing which is a cross-sectional View of an apparatus embodying the principles of this invention.

Referring now more particularly to the drawing, outer conductor it and inner conductor H are the normal elements of a coaxial line. On one end of the coaxial line a standard coaxial connector 52 is mounted. Inner conductor I! is hollow for a portion of its length to permit the male portion of the coaxial connector to enter and make connection therewith. On the other end of the coaxial line a shorting disk I3 is fastened, thereby shorting the outer conductor H] to the inner conductor I l. A material affording high loss of R.-F. energy, such as powdered iron dispersed in a binder, is disposed between conductors I and H as indicated at M. Lossy material I4 is tapered, i. e. the coaxial line at the end where disk i3 is mounted is completely filled and said lossy material tapers, becoming thinner toward the end where the coaxial connector I2 is mounted. Cooling fins is, constructed of copper or similar material of high radiating efficiency, are mounted around the outside of conductor III to prevent the lossy material from becoming overheated.

In operation, radio frequency energy passing along the coaxial line Ii! encounters the lossy material where it is dissipated in the form of heat. By making the lossy material increase in diameter, 1. e. afford decreasing air passage for the radio frequency energy between the inner and outer conductors, reflections of the radio frequency energy are minimized. The lossy material usually made long in relation to the wavelength of the radio frequency energy for which it is to be used thus producing a low standing wave ratio along the coaxial line over a wide frequency band.

While there ha been described what is at present considered to be the preferred embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the invention.

The invention claimed is:

A device for terminating a coaxial line, comprising a coaxial section having inner and outer conductors, means for short circuiting said outer conductor to said inner conductor at one end of said conductors, the other end of said conductors being adapted to be connected to said coaxial line, an energy dissipative tapered plug composed of powdered iron disposed in a binder, said plug being disposed between said outer and inner conductors With its entire outer surface secured to the inner surface of said outer conductor, said plug having one end thereof disposed at said one end of said conductors with its inner surface at its one end having a diameter equal to the outer diameter of said inner conductor, the inner surface of said plug at its other end having a diameter substantially equal to the inner diameter of said outer conductor, the thickness of said energy dissipative means varying from a maximum at said one end thereof to a minimum at said other end thereof, said plug having a length that is long relative to the wavelength of the energy to be conducted by said coaxial line, and cooling fins radially secured to said outer conductor for dissipating the heat energy generated in said energy dissipative plug.



References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,273,547 Von Radinger Feb. 17, 1942 2,35,809 Goldstine Aug. 1, 19d! 2,469,599 Tiley Oct. 15, 1946 2,412,805 Ford Dec. 17, 1946 2,438,915 Hansen Apr. 16, 1948 OTHER REFERENCES Microwave Transmission Design Data, published in May 1944 by Sperry Gyroscope Company, Inc, Manhattan Bridge Plaza, Brooklyn 1, New York.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2273547 *Oct 19, 1939Feb 17, 1942Telefunken GmbhOhmic resistance for ultra-short waves
US2354809 *Sep 18, 1942Aug 1, 1944Rca CorpTransmission line load for high frequencies
US2409599 *Apr 28, 1944Oct 15, 1946Philco CorpCoaxial line termination
US2412805 *Feb 5, 1944Dec 17, 1946Rca CorpUltra high frequency oscillation generator
US2438915 *Jul 30, 1943Apr 6, 1948Sperry CorpHigh-frequency terminating impedance
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2771565 *Aug 19, 1952Nov 20, 1956IttTraveling wave tubes
US2832045 *Apr 28, 1954Apr 22, 1958Bell Telephone Labor IncElectromagnetic wave power measuring device
US2844791 *Mar 4, 1952Jul 22, 1958Thompson Prod IncMicro wave power measuring instrument
US2875418 *Aug 26, 1954Feb 24, 1959Sperry Rand CorpHigh power resistive attenuator devices
US2946005 *Sep 14, 1955Jul 19, 1960Bird Electronic CorpHigh frequency thermocouple meter
US3254316 *Oct 2, 1963May 31, 1966Omni Spectra IncResistive termination wherein coaxial inner conductor is movable to improve connection to coaxial line
US4173018 *Jul 27, 1967Oct 30, 1979Whittaker CorporationAnti-radar means and techniques
US5742211 *Mar 22, 1996Apr 21, 1998Lockheed Martin Energy Systems, Inc.Attenuator
DE1011489B *Apr 30, 1954Jul 4, 1957Rohde & SchwarzKoaxialer Abschlusswiderstand oder koaxiales Daempfungsglied fuer sehr hochfrequenteelektrische Wellen
DE1076207B *Sep 6, 1957Feb 25, 1960Anders Erik GrusellAbschlusswiderstand fuer Leiter von elektromagnetischen Wellen
EP0023437A1 *May 23, 1980Feb 4, 1981The Bendix CorporationRadio frequency load resistor
U.S. Classification333/22.00R, 338/216
International ClassificationH01P1/24, H01P1/26
Cooperative ClassificationH01P1/266
European ClassificationH01P1/26D