US3105946A - Asymmetrically conductive transmission system using adjacent dielectric plate to concentrate field in gyromagnetic plate - Google Patents

Asymmetrically conductive transmission system using adjacent dielectric plate to concentrate field in gyromagnetic plate Download PDF

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Publication number
US3105946A
US3105946A US545882A US54588255A US3105946A US 3105946 A US3105946 A US 3105946A US 545882 A US545882 A US 545882A US 54588255 A US54588255 A US 54588255A US 3105946 A US3105946 A US 3105946A
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slab
gyromagnetic
dielectric
plate
magnetic
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US545882A
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English (en)
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Beljers Hugh Gerrit
Kint Louis Van Der
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US Philips Corp
North American Philips Co Inc
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US Philips Corp
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
    • H01P1/00—Auxiliary devices
    • H01P1/32—Non-reciprocal transmission devices
    • H01P1/36—Isolators
    • H01P1/365—Resonance absorption isolators

Definitions

  • the present invention relates to asymmetrically conductive transmission systems, or transmission systems in which electromagnetic waves are passed in one direction and are not passed in the opposite direction.
  • Such a system in which, in a waveguide at a point at which the magnetic vector of a wave to be passed or to be blocked, respectively, is circularly polarized, a strip of high-frequency magnetic material, for example, ferrite, is positioned.
  • the material in the direction at right angles to the plane of rotation of the said magnetic vector, is polarized in a degree sufiicient to produce ferromagnetic resonance.
  • a plate of dielectric material is positioned on one side of the magnetic strip having a dielectric constant at least substantially equal to the square root of the dielectric constant of the magnetic material, and a thickness at least substantially equal to one-fourth the velocity of light divided by the square root of the dielectric constant of the dielectric material multiplied by the frequency of the waves.
  • FIGURE is a cross-sectional diagram of an embodiment of the arrangement of the present invention.
  • a rectangular waveguide 1 has a size which, in the x-direction, is equal to a and which, in the y-direction, is equal to b.
  • Longitudinally magnetic waves of the type H can propagate in the Waveguide in the z-direction, that is, at right angles to the plane of the drawing.
  • the magnetic vector components H and H can be represented by while the component H is equal to zero.
  • p represents the propagation constant, which is where w is the angular frequency of the waves, c is the velocity of light, a is the size of the waveguide in the direction of the x-axis, and B is a constant.
  • the absolute values of these components are equal, and consequently an exactly circularly polarized magnetic rotating field is produced, the plane of rotation of the magnetic vector for waves propagating in the direction of the positive z-axis is opposite to that for waves in the opposite direction.
  • a thin strip 2, of ferrite is arranged at the abovementioned point in the wave-guide '1 .
  • the magnetic strip 2 extends through a certain distance in the direction of the axis of the waveguide and preferably is tapered at the ends in order to avoid undesirable reflections.
  • the magnetic strip 2 is polarized by a magnetic field H in the y-direction, that is, in the direction at right angles to the plane of rotation of the magnetic vector.
  • the rotating field components at right angles to one another will oppose each other so that there is no ferromagnetic absorption.
  • a very slight absorption persists, which may, for example, be due to dielectric losses :and magnetic losses caused by imperfection of the magnetic material and to the finite thickness of the magnetic strip.
  • Waves propagating in the waveguide in a direction [for which the sense of rotation of the magnetic vector at the point of the magnetic strip 2 is opposite to that of the precession movement will consequently be passed substantially unimpeded, whereas waves in the opposite direction are highly damped.
  • the attenuation in the first case may be equal to about 1.5 decibels and the attenuation in the second case may be equal to about 20 decibels.
  • this ratio can be mater-ially improved by positioning on the magnetic strip 2 a plate 3 of dielectric material, the dielectric constant of which is equal to the square root of the dielectric constant electric plate 3, in other words, approximately equal to one-fourth the Wavelength of the waves in the dielectric plate 3.
  • An explanation of this phenomenon might be that without the provision cf the dielectric plate 3 a certain reflect-ion of the Waves from the surface of the magnetic strip 2 occurs, so that a certain amount of wave energy can escape through the space between the righthand side wall of the strip 2 and the right-hand side-Wall of the waveguide 1.
  • the dielectric plate 3 which behaves as a quarter wavelength transformer, there will be better matching of the said space and the magnetic strip 2, so that the wave energy is concentrated to a higher degree on the magnetic strip 2 and the reflection from the surface of said magnetic strip is highly reduced.
  • This arrangement insures, as tests have shown, an attenuation of more than 50 decibels in the Waves propagating in the non-conductive direction.
  • the provision of a dielectric plate at the opposite side of the magnetic strip 2, that is, at the side remote from the axis of the waveguide produces little effect or may even produce a reverse effect.
  • a phase shift of 90 is produced between the radial and axial components of the magnetic field and the absolute values of these components at two predetermined distances from the waveguide axis are equal.
  • a ferrite cylinder may be positioned and polarization may be produced by means of a direct current sent through a conductor arrangd in the axis of the waveguide, which conductor does not interfere with the field since the axial component of the electric vector of the wave type H is Zero. Consequently, the magnetic lines of force are circles about the axis.
  • This asymmetrically conductive transmission system can, in accordance with the invention, be improved by the provision of a cylinder made of dielectric material, the dielectric constant or which is equal to the square root of the dielectric constant of the ferrite, and the thickness of which is equal to one-fourth the wavelength for waves Within the dielectric material.
  • This dielectric cylinder is positioned inside or outside the ferrite cylinder according as the radius of the latter has the maximum or the value at which the magnetic vectors are equal to one another.
  • a cylinder made of quartz, for example, may be utilized.
  • a strip of ferromagnetic material which exhibits the gyromagnetic effect positioned at said point within said waveguide, said ferromagnetic material being polarized in a degree sufficient to produce ferromagnetic resonance in a direction at right angles to the plane of rotation of said magnetic vector, and a plate of dielectric material positioned on one side of said ferromagnetic material strip, said plate having a dielectric constant substantially equal to the square root of the dielectric constant of said ferromagnetic material and a thickness substantially equal to one fourth the velocity of light divided by the square root of the dielectric constant of said dielectric material multiplied by the frequency of the waves in said system.
  • An asymmetric-ally conductive transmission system in which in a Waveguide at a point at which the magnetic vector of a wave which is to be passed or to be blocked respectively is circularly polarized, a strip of ferromagnetic material which exhibits the gyromagnetic effect is positioned, which material in the direction at right angles to the plane of rotation of the said magnetic vector is polarized in a degree sufficient to produce ferromagnetic resonance, comprising a plate of dielectric material positioned on one side of said ferromagnetic material strip, the dielectric constant of said dielectric plate being at least substantially equal to the square root of the dielectric constant of said ferromagnetic material, and the thickness of said dielectric plate being at least substantially equal'to one-fourth the velocity of light divided by the square root of the dielectric constant of said dielectric material multiplied by the frequency of the waves in said system.
  • An asymmetrically conductive transmission system comprising a wavegulide having a point at which the magnetic vector of a wave in said system is circularly polarized, a strip of ferromagnetic material which exhibits the gyrcmagnetic effect positioned at said point within said waveguide, said ferromagnetic material being polarized in a degree sufficient to produce ferromagnetic resonance in a direction at right angles to the plane of rotation of said magnetic vector, and a plate of nonmagnetic dielectric material positioned substantially adjacent one side of said ferromagnetic material strip, said plate having a thickness substantially equal to one-fourth the wavelength of the waves in the said plate.
  • An asymmetrically conductive transmission system comprising a wave-guide having a point at which the magnetic vector of a wave in said system is circularly polarized, a strip of ferromagnetic material which exhibits the gyromagnetic effect positioned at said point within said waveguide, said ferromagnetic material being polarized in a degree sufiicient to produce ferromagnetic resonance in a direction at right angles to the plane of rotation of said magnetic vector, and a plate of dielectric material positioned on one side of said ferromagnetic material strip, said plate having a dielectric constant substantially equal to the square root of the dielectric constant of said ferromagnetic material and a thickness in the transverse the wave-s in said system.
  • a nonreciprocal dominant mode electromagnetic wave energy component comprising a section of rectan gular waveguide for said energy having conductive top and bottom wide walls and conductive narrow side walls, a slab of magnetically polarizable material having a :given high dielectric constant and exhibiting gyromagnetic effects in the presence of said energy extending within said section parallel to and at unequal distances hrom rmpective narrow side walls, said slab having a transverse dimension parallel to said Wide walls that extends through a first region in which said energy has transverse and longitudinal magnetic field components of equal amplitude into the region on each side of said first region in which said components are of slightly different amplitude, means for applying a magnetic biasing field to said gyromagnetic slab in a direction transverse to the direction of energy propagation through said guide, solely a single solid self-supporting slab of nonmagnetic high dielectric-constant dielectric material having a rectangular transverse cross section with a thickness parallel to said wide walls at least as great as said transverse dimension of

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  • Waveguides (AREA)
  • Waveguide Switches, Polarizers, And Phase Shifters (AREA)
US545882A 1954-11-19 1955-11-09 Asymmetrically conductive transmission system using adjacent dielectric plate to concentrate field in gyromagnetic plate Expired - Lifetime US3105946A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL793164X 1954-11-19

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US3105946A true US3105946A (en) 1963-10-01

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US (1) US3105946A (de)
BE (1) BE542862A (de)
DE (1) DE962182C (de)
FR (1) FR1135664A (de)
GB (1) GB793164A (de)
NL (2) NL91369C (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3569868A (en) * 1969-02-25 1971-03-09 Rca Corp Nonreciprocal microwave devices using a semiconductor element
US4651115A (en) * 1985-01-31 1987-03-17 Rca Corporation Waveguide-to-microstrip transition
US5663693A (en) * 1995-08-31 1997-09-02 Rockwell International Dielectric waveguide power combiner

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE549727A (de) * 1955-07-22
US3004225A (en) * 1958-06-25 1961-10-10 Bell Telephone Labor Inc Traveling wave solid state masers
US3035235A (en) * 1959-05-06 1962-05-15 Bell Telephone Labor Inc Field displacement isolator
NL260120A (de) * 1960-02-03
US3056097A (en) * 1960-07-15 1962-09-25 Ferrotec Inc Variable attenuator

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2538771A (en) * 1944-08-02 1951-01-23 Sperry Corp High-frequency attenuator
USRE23950E (en) * 1946-12-23 1955-02-22 Method and means for chemical analysis
US2731603A (en) * 1946-11-02 1956-01-17 Polytechnic Inst Brooklyn Matched wave guide attenuators
US2741744A (en) * 1951-05-08 1956-04-10 Driscoll Clare Microwave apparatus for circular polarization
US2745069A (en) * 1950-05-17 1956-05-08 Bell Telephone Labor Inc Microwave magnetized ferrite attenuator
US2787765A (en) * 1952-08-15 1957-04-02 Bell Telephone Labor Inc Magnetically controlled ferrite phase shifter having birefringent properties
US2877144A (en) * 1954-05-19 1959-03-10 Hughes Aircraft Co Vitreous coated magnetic material
US2909738A (en) * 1953-08-17 1959-10-20 Bell Telephone Labor Inc Broadband nonreciprocal devices

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2538771A (en) * 1944-08-02 1951-01-23 Sperry Corp High-frequency attenuator
US2731603A (en) * 1946-11-02 1956-01-17 Polytechnic Inst Brooklyn Matched wave guide attenuators
USRE23950E (en) * 1946-12-23 1955-02-22 Method and means for chemical analysis
US2745069A (en) * 1950-05-17 1956-05-08 Bell Telephone Labor Inc Microwave magnetized ferrite attenuator
US2741744A (en) * 1951-05-08 1956-04-10 Driscoll Clare Microwave apparatus for circular polarization
US2787765A (en) * 1952-08-15 1957-04-02 Bell Telephone Labor Inc Magnetically controlled ferrite phase shifter having birefringent properties
US2909738A (en) * 1953-08-17 1959-10-20 Bell Telephone Labor Inc Broadband nonreciprocal devices
US2877144A (en) * 1954-05-19 1959-03-10 Hughes Aircraft Co Vitreous coated magnetic material

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3569868A (en) * 1969-02-25 1971-03-09 Rca Corp Nonreciprocal microwave devices using a semiconductor element
US4651115A (en) * 1985-01-31 1987-03-17 Rca Corporation Waveguide-to-microstrip transition
US5663693A (en) * 1995-08-31 1997-09-02 Rockwell International Dielectric waveguide power combiner

Also Published As

Publication number Publication date
DE962182C (de) 1957-04-18
NL91369C (de)
GB793164A (en) 1958-04-09
BE542862A (de)
NL192523A (de)
FR1135664A (fr) 1957-05-02

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