US2736866A - Filter for transmission line - Google Patents

Filter for transmission line Download PDF

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Publication number
US2736866A
US2736866A US152132A US15213250A US2736866A US 2736866 A US2736866 A US 2736866A US 152132 A US152132 A US 152132A US 15213250 A US15213250 A US 15213250A US 2736866 A US2736866 A US 2736866A
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US
United States
Prior art keywords
filter
conductor
sections
diameter
section
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
US152132A
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English (en)
Inventor
Andre G Clavier
David L Thomas
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.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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 NL98681D priority Critical patent/NL98681C/xx
Priority to NL7403649.A priority patent/NL160075B/xx
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
Priority to US152132A priority patent/US2736866A/en
Priority to GB389/51A priority patent/GB683352A/en
Priority to FR1034212D priority patent/FR1034212A/fr
Priority to DEI3948A priority patent/DE898339C/de
Application granted granted Critical
Publication of US2736866A publication Critical patent/US2736866A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/20—Frequency-selective devices, e.g. filters
    • H01P1/201—Filters for transverse electromagnetic waves

Definitions

  • This invention relates to microwave transmission systems and more particularly to a filter and means for coupling the filter in a microwave transmission system.
  • One of the objects of this invention is to provide a filter for passage of certain microwave frequencies.
  • Another object is to provide a combined filter and coupling arrangement for coupling the filter to certain types of microwave transmission conductors.
  • One of the features of the invention is to utilize a conductor corresponding to the so-called surface wave conductor as a filter. This is done by disposing enlarged conductive sections such as discs or plates at spaced in- ⁇ tervals along the conductor, the spacing depending upon'v the frequency energy to be passed. To avoid or minimize perturbation in the propagation of microwave energy, the disc sections at the ends of the filter are made gradually smaller in diameter or cross-sectional dimension until the last one at each end is nearly the same cross-sectional size as the Wire conductor.
  • the filter conductor and disc sections may be bare of insulation but in order to confine the electromagnetic field throughout the length ofthe filter, it is preferable to coat with insulation the conductor and disc sections similarly as the single wire surface wave conductor associated therewith.
  • the disc sections may be circular, elliptical, rectangular, triangular, or any other shape that does not produce undue perturbation in the wave propagation.
  • Another feature of tne invention is the manner in which the filter is coupled between a coaxial line or waveguide and a surface wave conductor.
  • the end of the waveguide structure or the outer conductor of a coaxial line is ared outwardly and the tapered end sections of the filter are disposed at least partly within the said fiared portion.
  • the tapered filter section or sections are disposed axially of this expanding zone so that a minimum amount of perturbation occurs.
  • Fig. l is a view in side elevation of a filter according to the principles of this invention.
  • Fig-2 is a longitudinal sectional view of the same type of filter shown with tapered end sections coupled to a surface wave conductor;
  • Fig. 3 is a longitudinal sectional view of the filter coupled to a dielectric waveguide
  • Fig. 4 is a longitudinal sectional view showing a modified filter structure coupled to a coaxial line.
  • the spacing intervals d have a direct bearing upon the frequency band that may be passed by the filter.
  • the upper cut-off wave length of the filter may be represented by the formula ) ⁇ c
  • a narrow band pass filter may be constructed by using two such filters in series, one of the filters being proportioned as a high pass filter and the other as a low pass filter.
  • the filter shown in Fig. 1 is bare of insulation but may be coated with insulation, such as enamel, glass, poly styrene, polyethylene, etc., where it is desired to have the y electromagnetic field along the filter confined closely 'grasses adjacent the filter sections.
  • the filter therein shown is provided with such an insulating coating as indicated at 3.
  • the filter structure of Fig. 2 is provided with end portions which minimize the perturbation of the microwave propagation in either direction with respect to the filter.
  • the end sections are shown to comprise a plurality of discs 4, the diameters of which are progressively diminished from adjacent one of the discs of maximum diameter to the endmost disc 5 of the filter, the end disc 5 being slightly larger than the diameter of the conductor 1.
  • the conductor 1 beyond the endmost section 5 may be coupled to or made integral with a surface wave line conductor 6 or may itself comprise a part of the line conductor 6.
  • the conductor 1 and the disc line sections of the filter are all shown to be coated with a layer of insulation 3 of a thickness corresponding to the insulation on the line conductor 6. It will be clear, however, that the coating of insulation on the filter conductor and sections may be either thicker or thinner than the coating on the conductor depending on the permissible diameter of electromagnetic field about the filter as well as the filtering action thereof.
  • a filter with terminatingl tapered sections as shown in Fig. 2 is shown coupled to a hollow conductor 7 which may comprise a circular wall structure of a waveguide or the outer conductor of a coaxial line.
  • the end portion 8 of the hollow conductor may be plane but preferably is fiared in the form of a horn and certain of the end sections of the lter are disposed within this flared portion.
  • the end lter section 5 is disposed closely adjacent the inner end of the iiared portion 8 so that the taper of the end sections associated therewith corresponds proportionately to the angular degree of the ared portion 8 which is concentrically disposed thereabout.
  • a similar microwave transmission line of the coaxial type is shown as comprising an outer conductor 11 and an inner conductor 12.
  • the outer conductor is also flared as shown by the end portion 13.
  • the hollow conductor 11 contains a solid dielectric 14 which extends at the same diameter outwardly through the flared portion 13.
  • the filter in this embodiment is provided with a tapered end section 15 which has a maximum diameter D corresponding to the diameter of the other sections 16 of the filter.
  • the end section 15 is tapered from its end of maximum diameter to the surface of the conductor 12 substantially in radial alignment with the inner end 17 of the ared portion 13.
  • the section 15 is proportioned to extend for a length equal to or slightly larger than the length of the fiared portion 13 of the outer conductor.
  • the tapered end portion of the filter is disposed within the flared horn end of the outer conductor. This relationship provides for smooth transfer of energy from manner of propagation to another with a minimum of perturbation.
  • the dielectric body contained in the conductor 11 is gradually diminished in thickness along the section 15 until it reaches the uniform thickness of insulation on the filter. This gradual change in the dielectric also aids in minimizing the occurrence of perturbation of the wave propagation.
  • the discs may be of various shapes so long as the longitudinal cross-sections thereof are symmetrical. Also, the discs may be made separately and secured to the conductor or they may be made integral therewith. This description is therefore to be regarded as being made only by way of example and not as a limitation to the scope of our invention as set forth in the objects thereof and in the accompanying claims.
  • a high frequency filter according to claim l wherein said enlarged sections ⁇ are coated with insulating material.
  • a high frequency filter according to claim l wherein the conductor and the enlarged sections thereof are coated with insulating material.
  • a high frequency filter according to claim l wherein the end sections of the filter are graduated in size with the endmost section slightly larger than the diameter of the conductor.
  • a high frequency filter according to claim 4 wherein the conductor and the enlarged sections are coated with insulating material with the insulation Iadjacent the end section being tapered from the periphery of said end section to closely adjacent the surface of said conductor.
  • a high frequency filter according to claim l wherein the diameters of the conductor sections are approximately equal and the end section is tapered from la diameter Isubstantially equal to the diameter of the other sections down to the diameter of said conductor.
  • a high frequency filter according to claim l further including a hollow waveguide conductor coupled to one end of the filter, and the end portion of said filter being disposed at least partly within the end portion of said end section being disposed substantially within the ared portion of said hollow conductor.
  • Ahigh frequency filter according to claim 9 Wherein the end sections are of progressively smaller diameter in the direction of the endmost section.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Control Of Motors That Do Not Use Commutators (AREA)
  • Waveguides (AREA)
US152132A 1950-03-27 1950-03-27 Filter for transmission line Expired - Lifetime US2736866A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
NL98681D NL98681C (instruction) 1950-03-27
NL7403649.A NL160075B (nl) 1950-03-27 Langwerpige ventilatiekapconstructie voor een dak van een gebouw.
US152132A US2736866A (en) 1950-03-27 1950-03-27 Filter for transmission line
GB389/51A GB683352A (en) 1950-03-27 1951-01-05 Filter for transmission line
FR1034212D FR1034212A (fr) 1950-03-27 1951-03-20 Filtre pour ligne de transmission
DEI3948A DE898339C (de) 1950-03-27 1951-03-25 Hochfrequenzfilter in Verbindung mit einem Hochfrequenzwellenleiter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US152132A US2736866A (en) 1950-03-27 1950-03-27 Filter for transmission line

Publications (1)

Publication Number Publication Date
US2736866A true US2736866A (en) 1956-02-28

Family

ID=22541639

Family Applications (1)

Application Number Title Priority Date Filing Date
US152132A Expired - Lifetime US2736866A (en) 1950-03-27 1950-03-27 Filter for transmission line

Country Status (5)

Country Link
US (1) US2736866A (instruction)
DE (1) DE898339C (instruction)
FR (1) FR1034212A (instruction)
GB (1) GB683352A (instruction)
NL (2) NL98681C (instruction)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2807784A (en) * 1952-03-17 1957-09-24 Csf Coupling and matching device for external circuits of a traveling wave tube
US3025478A (en) * 1959-05-27 1962-03-13 Bell Telephone Labor Inc Microwave devices for waveguides of circular cross section
US3513416A (en) * 1967-01-30 1970-05-19 Varian Associates Cylindrical surface horn forming a transition between a closed periodic circuit and an open sided periodic circuit

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1081196A (fr) * 1953-04-24 1954-12-16 Csf Aérien pour ondes électromagnétiques courtes

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB287503A (en) * 1927-03-22 1929-02-14 Spezialfabrik Fuer Aluminium S Process for producing insulating coverings on wires, bands, plates, or sheets of aluminium or aluminium alloys
US2207845A (en) * 1938-05-28 1940-07-16 Rca Corp Propagation of waves in a wave guide
US2342736A (en) * 1940-10-01 1944-02-29 Herzog Robert Radio cable
US2387783A (en) * 1943-02-01 1945-10-30 Sperry Gyroscope Co Inc Transmission line
US2419855A (en) * 1939-06-22 1947-04-29 Roosenstein Hans Otto Arrangement adapted to suppress radio frequency currents on conductors
US2438795A (en) * 1943-12-13 1948-03-30 Hazeltine Research Inc Wave-guide system
US2438913A (en) * 1941-10-31 1948-04-06 Sperry Corp High-frequency filter structure
US2479687A (en) * 1943-05-17 1949-08-23 Rca Corp Super high frequency filter
US2497707A (en) * 1945-02-21 1950-02-14 Gen Electric Method for making high-frequency cable joints
US2567718A (en) * 1945-09-24 1951-09-11 Roland W Larson Tapered corrugated line
US2588610A (en) * 1946-06-07 1952-03-11 Philco Corp Directional antenna system
US2643353A (en) * 1948-11-04 1953-06-23 Int Standard Electric Corp Traveling wave tube
US2659817A (en) * 1948-12-31 1953-11-17 Bell Telephone Labor Inc Translation of electromagnetic waves
US2688732A (en) * 1949-05-05 1954-09-07 Bell Telephone Labor Inc Wave guide

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE600011C (de) * 1932-08-13 1934-07-16 Telefunken Gmbh Stabfoermige Leitung fuer hochfrequente Stroeme, insbesondere Antenne

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB287503A (en) * 1927-03-22 1929-02-14 Spezialfabrik Fuer Aluminium S Process for producing insulating coverings on wires, bands, plates, or sheets of aluminium or aluminium alloys
US2207845A (en) * 1938-05-28 1940-07-16 Rca Corp Propagation of waves in a wave guide
US2419855A (en) * 1939-06-22 1947-04-29 Roosenstein Hans Otto Arrangement adapted to suppress radio frequency currents on conductors
US2342736A (en) * 1940-10-01 1944-02-29 Herzog Robert Radio cable
US2438913A (en) * 1941-10-31 1948-04-06 Sperry Corp High-frequency filter structure
US2387783A (en) * 1943-02-01 1945-10-30 Sperry Gyroscope Co Inc Transmission line
US2479687A (en) * 1943-05-17 1949-08-23 Rca Corp Super high frequency filter
US2438795A (en) * 1943-12-13 1948-03-30 Hazeltine Research Inc Wave-guide system
US2497707A (en) * 1945-02-21 1950-02-14 Gen Electric Method for making high-frequency cable joints
US2567718A (en) * 1945-09-24 1951-09-11 Roland W Larson Tapered corrugated line
US2588610A (en) * 1946-06-07 1952-03-11 Philco Corp Directional antenna system
US2643353A (en) * 1948-11-04 1953-06-23 Int Standard Electric Corp Traveling wave tube
US2659817A (en) * 1948-12-31 1953-11-17 Bell Telephone Labor Inc Translation of electromagnetic waves
US2688732A (en) * 1949-05-05 1954-09-07 Bell Telephone Labor Inc Wave guide

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2807784A (en) * 1952-03-17 1957-09-24 Csf Coupling and matching device for external circuits of a traveling wave tube
US3025478A (en) * 1959-05-27 1962-03-13 Bell Telephone Labor Inc Microwave devices for waveguides of circular cross section
US3513416A (en) * 1967-01-30 1970-05-19 Varian Associates Cylindrical surface horn forming a transition between a closed periodic circuit and an open sided periodic circuit

Also Published As

Publication number Publication date
DE898339C (de) 1953-11-30
FR1034212A (fr) 1953-07-21
NL160075B (nl)
NL98681C (instruction)
GB683352A (en) 1952-11-26

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