US2405437A - Impedance matching transformer - Google Patents

Impedance matching transformer Download PDF

Info

Publication number
US2405437A
US2405437A US456941A US45694142A US2405437A US 2405437 A US2405437 A US 2405437A US 456941 A US456941 A US 456941A US 45694142 A US45694142 A US 45694142A US 2405437 A US2405437 A US 2405437A
Authority
US
United States
Prior art keywords
conductor
impedance
section
matching
conductors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US456941A
Other languages
English (en)
Inventor
Laurance M Leeds
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to BE478854D priority Critical patent/BE478854A/xx
Application filed by General Electric Co filed Critical General Electric Co
Priority to US456941A priority patent/US2405437A/en
Application granted granted Critical
Publication of US2405437A publication Critical patent/US2405437A/en
Priority to FR949099D priority patent/FR949099A/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P5/00—Coupling devices of the waveguide type
    • H01P5/04—Coupling devices of the waveguide type with variable factor of coupling

Definitions

  • My invention relates to impedance matching transformers for a concentric transmission line and it has for its object to provide an improved impedance matching means for two dissimilar sections of such a line.
  • a transmission line having a length equal to a quarter of a wave length, or any odd multiple thereof, of the wave to be transmitted, to match two unequal'impedances is well known.
  • various types of balanced and unbalanced lines such as a two-wire balanced open line, two bar or strip balanced open lines, coaxial unbalanced lines, and similar composite lines have been employed for this purpose.
  • My invention itself, however, together with further objects and advan: tages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which Fig. 1 is a section of a transmission line employing the impedance matching transformer ofmy invention; Fig. 2 is a sectional view of the transformer of Fig. 1 on the line 2-2, and Figs. 3 and 4 are modifications of my impedance matching transformer.
  • the sections I0 and H comprise coaxial tubular outer conductors l3 and [4 having the same diameter and coaxial inner conductors l5 and I6 of different diameters.
  • the inner conductors are held in spaced relation with respect to the outer conductors by means of suitable insulators 28.
  • Section I 0 of the transmission line may be connected to some source of voltage, such as a radio transmitter, and section I l to some utilization means, for example an antenna. It will be realized of course that instead of connecting the transformer 12 to the section ll, it may be desired to connect this section directly to a load impedance.
  • the surge impedance Zn of the connecting line or quarter wave transformer in accordance with well known transmission line theory, is related to the other impedances by the relation ZO ZsZT.
  • ZO ZsZT the impedance of section II, that is the load impedance
  • the impedance of section Ill that is the sending end impedance
  • a precise value of Zn for-the impedance transformer I2 is obtained by making the electrical length of the section l2 equal to a quarter wave length at the angular velocity of the desired operating frequency and by providing in th section l2 an inner conductor I! which is eccentrically disposed with respect to the tubular outer conductor l8 and means foradjusting the amountof this eccentricity, conductor I! being connected to conductors l5 and U5 by means of the flexible cable l9.
  • Adjustment of 1 the position of conductor I! with respect tov the tubular conductor I8 is secured by means of the triadic insulator support shown in Fig. 2.
  • the members 20 suitably secured to the outer conductor I8, as by brazing or welding, have internally threaded bores 2
  • Rodlike members 23 of suitable insulating material havingenlarged head portions 24 externally threaded for engagement with the threads 2!, hold conductor I! in spaced relation with outer conductor [8.
  • Member 20 is likewise threaded overa portion. of its outer surface for engagement with cooperating threads on the interior of cap member 25.
  • sealing gasket 25 is provided between cap member 25 and a shoulder portion El on member 20.
  • the ratio of the outside diameter of conductor I! to the inside diameter of conductor 18 may or may not be different from the ratio of corresponding diameters in sections iii and H of the transmission line.
  • the impedance transformer I2 is used to match two lines or two sections of a line of different characteristic impedance and the above-mentioned diameter ratio for the section i2 is chosen to give substantially the correct surge, or characteristic, impedance for this matching section when the position of conductor l? with respect to conductor i8 is at approximately the midpoint of eccentric movement.
  • the surge impedance of the matching section l2 may be Varied above or below a calculated and expected value in order to obtain precise matching with sections it and H. Movement of the inner conductor I! from the midpoint of its eccentric path toward the axis of the transmission line is efi'ective to increase the surge impedance of the matching section it, while movement further from the axis is effective to decrease the surge impedance of this section.
  • v vi? the surge impedance can be determined. Taking suitable regard for the units, it is found that 4 33 of the section 32 in a non-coaxial position.
  • Conductor 33 is eccentrically mounted on bearing rods 34 non-coaxially supported in inner conductors 35 and 36. This particular construction is especially suitable for use in a cable which is not gas-filled. In such a case, the eccentricity of conductor 33 may be adjusted by inserting a suitable tool through opening 3! in the outer conductor 38 and rotating the conductor 33 on the bearings 34.
  • the triadic insulator support shown in Fig. 2 may be used in conjunction with matching section 32 as a means for more precisely determining and maintaining the proper eccentricity of conductor 33.
  • the inner conductors of the sections 40 and 4! and the matching section 42 are rigidly connected together and precise impedance matching of section 42 with sections 40 and 4! is obtained by moving the position of the tubular-outer conductor 13 with respect to thesolid inner conductor 46.
  • This construction is particularly desirable Where the conductors of the respective sections are of different diameter.
  • the inner conductors 4 45, and M are rigidly connected together, as by brazing or welding.
  • the tubular outer conductor 43 is joined to outer conductors 37 and 43 by means of the Sylphons or corrugated sections l9 and 59.
  • the rings 52 and 53 may be Welded to the plate 51 and ma be either brazed or welded to the outer conductors M and 48 or clamped thereto in any well known manner.
  • the triadic supporting means comprises the ring member 55 suitably se- 40 cured to plate 5! and the thumb-screw members as threadedly engaging ring 55.
  • my invention provides an unbalanced impedance matching transformer in which the surge impedance of the transformer can be varied for matching purposes, the variation being accomplished by moving one of the conductors of the matching transformer to .a non-coaxial position.
  • continuous variation of the surge impedance of the matching section is provided without disassembly of the transmission line.
  • the value of the required matching impedance may be obtained with speed, with ease, and with precision.
  • a transmission line section adapted for connection between adjacent ends of two concentric transmission lines of unequal surge impedance to match the impedance of one of said lines to that of the other, said transmission line section comprising an outer conductor adapted for connection between the outer conductors of said concentric lines and an inner conductor adapted for connection between the inner conductors of said concentric lines, means to move one of said conductors of said section in a direction transverse to the other conductor while maintaining said one conductor substantially parallel therewith to vary the eccentricity of said section to match said impedances, and yielding electrical connections between said one conductor and the conductors of said concentric lines to which it is connected to allow said movement by said means in said transverse direction.

Landscapes

  • Waveguides (AREA)
US456941A 1942-09-01 1942-09-01 Impedance matching transformer Expired - Lifetime US2405437A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
BE478854D BE478854A (en, 2012) 1942-09-01
US456941A US2405437A (en) 1942-09-01 1942-09-01 Impedance matching transformer
FR949099D FR949099A (fr) 1942-09-01 1947-07-08 Perfectionnements aux dispositifs d'adaptation d'impédance pour lignes électriques

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US456941A US2405437A (en) 1942-09-01 1942-09-01 Impedance matching transformer

Publications (1)

Publication Number Publication Date
US2405437A true US2405437A (en) 1946-08-06

Family

ID=23814767

Family Applications (1)

Application Number Title Priority Date Filing Date
US456941A Expired - Lifetime US2405437A (en) 1942-09-01 1942-09-01 Impedance matching transformer

Country Status (3)

Country Link
US (1) US2405437A (en, 2012)
BE (1) BE478854A (en, 2012)
FR (1) FR949099A (en, 2012)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2492155A (en) * 1945-08-11 1949-12-27 Standard Telephones Cables Ltd Tuning system
US2538544A (en) * 1948-06-16 1951-01-16 Wallauschek Richard Hyperfrequency wide-band impedance matching network
US2560685A (en) * 1946-10-24 1951-07-17 Rca Corp Variable inductance for use on very high frequencies
US2563578A (en) * 1951-08-07 Flexible corrugated seamless metal
US2567748A (en) * 1943-10-02 1951-09-11 Milton G White Control of wave length in wave guides
US2571021A (en) * 1945-08-08 1951-10-09 Harold C Early Flexible wave guide
US2604594A (en) * 1943-10-02 1952-07-22 Milton G White Arrangement for varying wave lengths in coaxial lines
US2623946A (en) * 1947-03-29 1952-12-30 Sperry Corp Transmission line transition
US2647241A (en) * 1949-10-17 1953-07-28 Westinghouse Electric Corp Tuning stub
US2659817A (en) * 1948-12-31 1953-11-17 Bell Telephone Labor Inc Translation of electromagnetic waves
US2699501A (en) * 1945-08-02 1955-01-11 Young Louise Rapid scanning device
US2774045A (en) * 1951-10-17 1956-12-11 Gen Electric Ultra-high-frequency tuner
US2782382A (en) * 1950-05-25 1957-02-19 Int Standard Electric Corp Attenuator for surface wave propagation
DE1015510B (de) * 1952-11-26 1957-09-12 British Telecomm Res Ltd Einstellbarer koaxialer Viertelwellenlaengentransformator
US2935705A (en) * 1956-09-26 1960-05-03 Martin Co Constant impedance balance line phase shifter
US3356971A (en) * 1951-11-14 1967-12-05 Arf Products Tuned circuit
US3417350A (en) * 1965-09-13 1968-12-17 Commerce Usa Variable impedance coaxial device with relative rotation between conductors
EP0225308A3 (en) * 1985-12-06 1989-05-03 Skandinavisk Torkteknik AB Co-axial transition of a magnetron
EP0328948A1 (fr) * 1988-02-12 1989-08-23 Alcatel Espace Filtre à résonateur diélectrique

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1022716B (de) * 1955-03-30 1958-01-16 Bbc Brown Boveri & Cie Verfahren zur Anpassung der in den Hochstromzuleitungen eines Lichtbogenofens liegenden Impedanz an den Betriebszustand des Ofens

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2563578A (en) * 1951-08-07 Flexible corrugated seamless metal
US2567748A (en) * 1943-10-02 1951-09-11 Milton G White Control of wave length in wave guides
US2604594A (en) * 1943-10-02 1952-07-22 Milton G White Arrangement for varying wave lengths in coaxial lines
US2699501A (en) * 1945-08-02 1955-01-11 Young Louise Rapid scanning device
US2571021A (en) * 1945-08-08 1951-10-09 Harold C Early Flexible wave guide
US2492155A (en) * 1945-08-11 1949-12-27 Standard Telephones Cables Ltd Tuning system
US2560685A (en) * 1946-10-24 1951-07-17 Rca Corp Variable inductance for use on very high frequencies
US2623946A (en) * 1947-03-29 1952-12-30 Sperry Corp Transmission line transition
US2538544A (en) * 1948-06-16 1951-01-16 Wallauschek Richard Hyperfrequency wide-band impedance matching network
US2659817A (en) * 1948-12-31 1953-11-17 Bell Telephone Labor Inc Translation of electromagnetic waves
US2647241A (en) * 1949-10-17 1953-07-28 Westinghouse Electric Corp Tuning stub
US2782382A (en) * 1950-05-25 1957-02-19 Int Standard Electric Corp Attenuator for surface wave propagation
US2774045A (en) * 1951-10-17 1956-12-11 Gen Electric Ultra-high-frequency tuner
US3356971A (en) * 1951-11-14 1967-12-05 Arf Products Tuned circuit
DE1015510B (de) * 1952-11-26 1957-09-12 British Telecomm Res Ltd Einstellbarer koaxialer Viertelwellenlaengentransformator
US2935705A (en) * 1956-09-26 1960-05-03 Martin Co Constant impedance balance line phase shifter
US3417350A (en) * 1965-09-13 1968-12-17 Commerce Usa Variable impedance coaxial device with relative rotation between conductors
EP0225308A3 (en) * 1985-12-06 1989-05-03 Skandinavisk Torkteknik AB Co-axial transition of a magnetron
EP0328948A1 (fr) * 1988-02-12 1989-08-23 Alcatel Espace Filtre à résonateur diélectrique

Also Published As

Publication number Publication date
FR949099A (fr) 1949-08-19
BE478854A (en, 2012)

Similar Documents

Publication Publication Date Title
US2405437A (en) Impedance matching transformer
US2451876A (en) Radio-frequency joint
US2540012A (en) Electrical connector
US2519933A (en) Rotatable joint for coaxial cables
US2226479A (en) Apparatus for mechanically and electrically connecting conductors carrying high frequency currents
US2446982A (en) Apparatus for broad-band radio transmission
US2433011A (en) Ultra high frequency energy coupling
GB579665A (en) Improvements in and relating to impedance matching transformers
US2437067A (en) Adjusting means for transmission lines
GB628046A (en) Improvements in electrical wave-signal coupling systems
US2453759A (en) Tapered union for concentric conductor lines
US2602118A (en) Capacitive rotatable coupler
US2743422A (en) Coaxial stub supports
US3136965A (en) Electromagnetic wave guide of lunate cross section
US3375474A (en) Microwave waveguide to coax coupling system
GB1116645A (en) Improvements in or relating to radio frequency transmission paths
US2121855A (en) Coupling high-frequency apparatus
US2451413A (en) Coupling device for concentric conductor lines
US2769169A (en) Dipole impedance matching device
US2515061A (en) Radio-frequency filter
US2597867A (en) High-frequency attenuating device
US2404832A (en) Switch for high-frequency electrical oscillations
US2644140A (en) Variable-length transmission line
US2484028A (en) High-frequency bridge circuit
US3197720A (en) Transmission line having frequency reject band