US2594978A - Wave guide attenuator - Google Patents

Wave guide attenuator Download PDF

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Publication number
US2594978A
US2594978A US491889A US49188943A US2594978A US 2594978 A US2594978 A US 2594978A US 491889 A US491889 A US 491889A US 49188943 A US49188943 A US 49188943A US 2594978 A US2594978 A US 2594978A
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United States
Prior art keywords
guide
strips
wave
strip
attenuator
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Expired - Lifetime
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US491889A
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English (en)
Inventor
Richard B Nelson
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General Electric Co
Original Assignee
General Electric Co
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Filing date
Publication date
Priority to FR964835D priority Critical patent/FR964835A/fr
Application filed by General Electric Co filed Critical General Electric Co
Priority to US491889A priority patent/US2594978A/en
Priority to GB11835/44A priority patent/GB583501A/en
Application granted granted Critical
Publication of US2594978A publication Critical patent/US2594978A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/22—Attenuating devices
    • H01P1/222—Waveguide attenuators

Definitions

  • My invention relates to ultra high frequency systems and more particularly to an attenuator for utilization therein.
  • ultra high frequency electromagnetic waves often referred to as microwaves
  • a guide of the hollow-pipe type which may be constructed of a conductive material and which contains a dielectric medium such as air or a gas through which the energy of the wave is transmitted.
  • the frequency of the exciting electromagnetic waves must be greater than the critical minimum frequency established by the dimensions, principally the transverse dimensions, of the guide.
  • I provide a new and improved attenuator for systems of this nature wherein accurately controllable and determinable amounts of energy may be transmitted upon energization or excitation of; the guide.
  • Figs. 1 and 2 which are, re.- spectively, a cross sectional vertical view and an end view, represent. one embodiment of my invention and apply to a wave guide of rectangular hollow-pipe type; Figs. 3 and i are, respectively, across sectional vertical view and an end view of another embodiment of my invention; and Fig. 5 is a cross sectional vertical view of a modification of the embodiment shown in Fig. 3.
  • a dielectric wave guide of the hollow-pipe which comprises a conductive or metallic guide I0 which may have a rectangular cross section.
  • the top and bottom of the guide may be defined by conductive or metallic plates II and I2 and the side walls, by plates l3 and I l.
  • the dielectric wave guide may be formed of any suitable conductive material, such as. copper or brass, and electromagnetic waves of the H01 type and of a frequency greater than the cutoff frequency of the guide may be propagated in a direction from left to right in Fig. 1, being supplied from any suitable source (not shown).
  • the high frequency waves traveling-along the guide ID are attenuated by means of a strip I5 comprising a resistive, material I6, such as finely divided graphite, coated on a thin piece I! of dielectric material, preferably of the molded phenolic resin type having a width substantially equal to the horizontal width of the opening within the guide ID.
  • the strip [5 i attached at its left-hand end to thebottom wall l2 of the wave guide by means of a screw I 8 and nut 19.
  • the opposite, or righthand, end of strip l5 has a longitudinal slot 29 therein and a screw 2!, which extends through the slot 20 and has a head portion larger than the. width of slot 29, is used in conjunction with a nut 22 to hold this end of the strip I5 against the inner surface of the bottom wall l2.
  • the center portion of the strip I5 is fixed inwardly into the guide In from the inner surface of wall [2. in a uniform curve between the fixed ends.
  • a screw 24 in threaded engagement with a hole in bottom wall 12 and having at its lower end a knurled head 25 and at its upper end a pair of washers 25, 2'! lying on opposite sides of the strip I5 around a slot 28, therein, provides mean for adjustably controlling thev amount. by which this central portion of strip l5 extends into guide I!) and, consequently, the attenutating effect of this strip of resistive material on the waves traveling through the guide.
  • the strip l may be positioned at the center of the guide where the electric field is strongest to increase the amount of attenuation, or Withdrawn to the inner surface of the bottom wall l2 to decrease the amount of attenuation. Because of the gradual nature of the Change in impedance in the direction of propagation, there is no sudden transition in the impedance characteristic of guide [0 to give reflections of the high frequency waves traveling therethrough. Therefore, the-amount of reflection caused by my adjustable attenuator is low for a wide range of frequencies. Moreover, the amount of attenuation may be calibrated in terms of the setting of the adjusting screw 25.
  • a fixed attenuator which gives even a smaller amount of refiection.than the attenuator of Figs. 1 and 2 is shown.
  • which may comprise a material similar to that of resistive strip l5, are shown as extending longitudinally along the opposite walls II and [2 of wave guide Ill.
  • are of equal length and of similar contour and the opposite ends of each strip are fixedly secured, as by gluing, to the inner surfaces of the opposite walls II, I2 of wave guide Hi.
  • are displaced longitudinally in the wave guide In by a distance equal to a quarter wave length at the frequency of the energy being transmitted through the guide. Since the strips 30, 3
  • the strips 32, 33 are made adjustable in position by means of adjusting screws 34, 35 of a construction similar to the adjusting screw 24 shown in Fig. 1.
  • the points of engagement of the screws 34, 35 with their respective strips 32, 33 are displaced longitudinally along the guide at a distance equal to a quarter wave length at the frequency of the wave being propagated.
  • the screws 34 and 35 may be mechanically linked, as indicated by the dotted line 36, for uni-control so that the strips 32 and 33 are projected toward the center of the guides simultaneously and in exactly equal amounts.
  • An attenuator for high frequency energy in a dielectric wave guide system of the rectangular hollow-pipe type comprising a pair of strips of resistance material extending longitudinally along said guide, each of said strips having its ends attached to the inner surface of an opposite wall of said guide and its center portion extending inwardly from its respective wall a desired distance, corresponding ends of said strips being displaced longitudinally in said guide by a distance equal to a quarter wave length at the frequency of said energy.
  • An attenuator for high frequency energy in a dielectric wave guide system of the rectangular hollow-pipe type comprising a pair of strips of resistance material extending longitudinally along said guide, each of said strips having its ends attached to the inner surface of an opposite wall of said guide, corresponding ends of said strips being displaced longitudinally in said guide by a distance equal to a quarter wave length at the frequency of said energy, and means for adjustably projecting the intermediate portions of said strips from said respective wall toward the center of said guide.
  • a hollow tubular guide for an electromagnetic wave said guide having a, conductive inner surface, a pair of elongated flexible strips, each having a conductive surface layer on at least one side thereof with a resistance substantially greater than that of said guide surface, said strips being positioned within said guide with each strip extending lengthwise of the guide with said side substantially parallel to the electric field of said wave and each strip being secured to a wall of said guide at two points spaced lengthwise of the strip, at least one of said points comprising a slidable connection, said strips being mounted along opposite walls of said guide, and means engaging both of said strips intermediate said two points on each to effect bowing of said strips, said means being adjustable to vary simultaneously the extent of bowing of both strips and thereby vary the attenuation offered by the strips to said wave.
  • a hollow tubular guide for an electromagnetic wave said guide having a conductive inner surface and a rectangular transverse section with a pair of wide walls and a pair of narrow walls, a pair of elongated strips, each having a conductive surface layer on at least one side thereof with a resistance substantially greater than that of said guide surface, said strips being positioned within said guide alongside opposite narrow walls thereof, each of said strips extending lengthwise of said guide with said side of the strip substantially perpendicular to said wide walls and being secured to the corresponding narrow wall at two points spaced lengthwise of the strip, the connection at one of said points being slidable, and means engaging both of said strips intermediate said two points on each to effect bowing of said strips, said means being adjustable to vary simultaneously the extent of bowing of both strips and thereby vary the amount of attenuation o1- fered thereby to said wave.
  • a variable attenuator comprising a section of wave guide of rectangular cross-section in which said guide has unequal cross-sectional dimensions, a pair of resistive vanes positioned within said guide substantially opposite each other and substantially parallel to the sides of site directions through substantially equal distances.
  • a variable attenuator comprising a section of wave guide of rectangular cross-section in which said guide has unequal cross-sectional dimensions, a pair of elongated resistive members positioned within said guide adjacent the sides of said guide having the shorter dimension, said members having portions which are coextensive longitudinally of said guide, and means for moving the central portions of said members laterally in opposite directions through substantially equal distances.

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  • Non-Reversible Transmitting Devices (AREA)
US491889A 1943-06-23 1943-06-23 Wave guide attenuator Expired - Lifetime US2594978A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
FR964835D FR964835A (enrdf_load_stackoverflow) 1943-06-23
US491889A US2594978A (en) 1943-06-23 1943-06-23 Wave guide attenuator
GB11835/44A GB583501A (en) 1943-06-23 1944-06-21 Improvements in and relating to attenuators for wave guides

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US491889A US2594978A (en) 1943-06-23 1943-06-23 Wave guide attenuator

Publications (1)

Publication Number Publication Date
US2594978A true US2594978A (en) 1952-04-29

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Family Applications (1)

Application Number Title Priority Date Filing Date
US491889A Expired - Lifetime US2594978A (en) 1943-06-23 1943-06-23 Wave guide attenuator

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US (1) US2594978A (enrdf_load_stackoverflow)
FR (1) FR964835A (enrdf_load_stackoverflow)
GB (1) GB583501A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2656518A (en) * 1946-01-15 1953-10-20 Westinghouse Electric Corp Wave guide attenuator
US2705780A (en) * 1946-11-02 1955-04-05 Polytechnie Inst Matched resistance film type wave guide attenuators
US2796588A (en) * 1946-02-01 1957-06-18 Richard M Walker Compact waveguide attenuator
US3022474A (en) * 1960-01-08 1962-02-20 Don Lan Electronics Inc Micro-wave attenuator
US3041558A (en) * 1955-03-24 1962-06-26 Gen Electric Waveguide system
DE1263884B (de) * 1960-07-26 1968-03-21 Goltermann Verlustbehafteter Hohlleiterbauteil mit geringer Reflexion
US3450990A (en) * 1957-01-16 1969-06-17 Gilfillan Corp Frequency indication system

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2567210A (en) * 1947-07-23 1951-09-11 Sperry Corp Ultra-high-frequency attenuator
US2673962A (en) * 1949-01-18 1954-03-30 Bell Telephone Labor Inc Mode suppression in curved waveguide bends
GB668508A (en) * 1950-05-09 1952-03-19 Standard Telephones Cables Ltd Improvements in or relating to cavity resonators
US2679632A (en) * 1950-06-28 1954-05-25 Bell Telephone Labor Inc Directional coupler
BE527584A (enrdf_load_stackoverflow) * 1952-05-08
DE962181C (de) * 1953-02-20 1957-04-18 Siemens Ag Einrichtung zur Einstellung der Phasenlage einer elektromagnetischen Schwingung in einem Hohlleiter mit rechteckfoermigem Querschnitt
FR2528632A1 (fr) * 1982-06-15 1983-12-16 Thomson Csf Dispositif de mesure du taux d'harmoniques d'un tube hyperfrequences

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2197123A (en) * 1937-06-18 1940-04-16 Bell Telephone Labor Inc Guided wave transmission

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2197123A (en) * 1937-06-18 1940-04-16 Bell Telephone Labor Inc Guided wave transmission

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2656518A (en) * 1946-01-15 1953-10-20 Westinghouse Electric Corp Wave guide attenuator
US2796588A (en) * 1946-02-01 1957-06-18 Richard M Walker Compact waveguide attenuator
US2705780A (en) * 1946-11-02 1955-04-05 Polytechnie Inst Matched resistance film type wave guide attenuators
US3041558A (en) * 1955-03-24 1962-06-26 Gen Electric Waveguide system
US3450990A (en) * 1957-01-16 1969-06-17 Gilfillan Corp Frequency indication system
US3022474A (en) * 1960-01-08 1962-02-20 Don Lan Electronics Inc Micro-wave attenuator
DE1263884B (de) * 1960-07-26 1968-03-21 Goltermann Verlustbehafteter Hohlleiterbauteil mit geringer Reflexion

Also Published As

Publication number Publication date
FR964835A (enrdf_load_stackoverflow) 1950-08-25
GB583501A (en) 1946-12-19

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