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Effect of the dielectric filling on the phase behaviour of the circular waveguide with azimuthally magnetized ferrite toroid and dielectric cylinder

Effect of the dielectric filling on the phase behaviour of the circular waveguide with azimuthally magnetized ferrite toroid and dielectric cylinder,1

Effect of the dielectric filling on the phase behaviour of the circular waveguide with azimuthally magnetized ferrite toroid and dielectric cylinder   (Citations: 9)
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The phase characteristics of the circular waveguide, comprising an azimuthally magnetized ferrite toroid and a dielectric cylinder of relative permittivity, larger than that of the ferrite, under normal TE01 mode excitation, are figured. The analysis reveals that they are finite for both directions of magnetization, limited by the cut-off frequencies and by specific envelope lines, depending on certain positive real numbers (L numbers), related to the roots of the characteristic equation of the structure. The expansion of the region, occupied by dielectric and the increase of its relative permittivity entails a moving of the position and a shortening of the length of the curves mentioned (a shrinking of the areas of wave propagation), as well as a change of the sign of the differential phase shift provided.
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    • ...The circular waveguides, completely or partially filled with azimuthally magnetized ferrite that support normal n TE0 modes, are suitable for the development of various passive microwave components: phase shifters, cut-off switches and isolators with application in the electronically scanned antenna arrays [1-9]...
    • ...Finding them, however, is a very difficult task [1-7]...
    • ... the coaxial ferrite geometry with an axial conductor of finite thickness [3]; iii) the two-layered circular configuration whose inner area is occupied by ferrite and the outer one – by isotropic dielectric, assuming identical values of the relative permittivities of the media [1]; iv) the two-layered circular transmission line with an inner area, taken by isotropic dielectric and an outer one – by ferrite of relative permittivity less [5], ...
    • ...The transmission lines studied are nonreciprocal (their properties depend on the sign of ferrite magnetization) [1-7]...
    • ...procedure, using the zeros of the relevant characteristic equations) reveals their main features [1-7]: i) There are sets of values of the parameters of the configurations: of the waveguide radius, of the central switching conductor to waveguide radius ratio (if the geometry is coaxial), of the central ferrite (dielectric) cylinder to waveguide radius ratio (in case the structure is double-layered and the anisotropic load is located in its ...
    • ...the ferrite permeability tensor, of the ratio of the relative permittivities of the ferrite and dielectric medium (on the understanding that the line comprises two strata) and frequencies for which propagation along the positive z – direction of their axes is possible both for (only for) positive (counter-clockwise) and (or only for) negative (clockwise) magnetization [1-7]; ii) For each of the aforesaid sets and for frequencies, greater ...
    • ...are different and partially overlap [1-7]; iii) The cut-off frequencies of geometries depend on the magnitude of α but not on its sign...
    • ...r – plane, pertinent to them serve as sources of pairs of phase characteristics for each α [1-7]; iv) The curves brought up may be finite, terminating at a peculiar envelop line(s) or infinite, going beyond the frequency range above...
    • ...These from the side of higher frequencies are formed by the envelopes referred to [1-7]; v) The abscissas of the points of the envelopes are functions of certain positive real numbers ( L numbers) [1-7]; vi) Under the conditions of item ii), if there are two working points, it may hold: + − > β β , + − < β β or...
    • ...These from the side of higher frequencies are formed by the envelopes referred to [1-7]; v) The abscissas of the points of the envelopes are functions of certain positive real numbers ( L numbers) [1-7]; vi) Under the conditions of item ii), if there are two working points, it may hold: + − > β β , + − < β β or...
    • ...In case there is solely one working point, latching r M brings the geometry from transmission to a state in which it does not sustain the electromagnetic fields [1-7]; vii) A magnetically controlled cut-off is observed in which the structures do not guide the modes or are in a propagation regime when the direction of magnetization is reversed [1-7]; viii) There is a region of double-valuedness of the phase curves for 0...
    • ...In case there is solely one working point, latching r M brings the geometry from transmission to a state in which it does not sustain the electromagnetic fields [1-7]; vii) A magnetically controlled cut-off is observed in which the structures do not guide the modes or are in a propagation regime when the direction of magnetization is reversed [1-7]; viii) There is a region of double-valuedness of the phase curves for 0...
    • ...below cut-off. A forward and a backward wave with different phase constants might get excited in it [1-7]...
    • ...ε ≠ [5,7], discloses the following complementary features of the double-layered configurations: i) The phase curves for both signs of magnetization of the filling are finite...
    • ...[1,4,5,7]); iii) The one of the two characteristics, belonging to certain pair for the same α lies partly or entirely below and the other one – entirely above cut-off...
    • ...zero) function of its parameters) [1,4,5,7]...

    Mariana Nikolova Georgieva-Grosseet al. Transmission properties of the circular waveguides completely or parti...

    • ...The development of nonreciprocal digital phase shifters, operating in the normal 01 TE mode, is one of the basic reasons for investigation of the circular waveguides with azimuthally magnetized ferrite [1]-[8]...
    • ...Different configurations with such type of filling have been studied and some peculiarities of their transmission properties have been revealed [1]-[8]...

    M. N. Georgieva-Grosseet al. Differential phase shift characteristics of normal TE0n modes in an az...

    • ...The study of the phase and differential phase shift characteristics of the circular ferrite waveguides with azimuthal magnetization, propagating normal 01 TE mode is of interest in view of the potentialities of these transmission lines as nonreciprocal digital phase shifters [1-4]...

    Georgi Nikolov Georgievet al. Analysis of the differential phase shift in the circular ferrite-diele...

    • ...It is considered that the circular waveguides, containing coaxially positioned cylindrical or toroidal inserts of azimuthally magnetized ferrite that sustain normal 01 TE mode, are natural microwave structures for digital nonreciprocal phase shifters [1-16]...

    Mariana Nikolova Georgieva-Grosseet al. Criteria for phase shifter operation of an azimuthally magnetized coax...

    • ...Under certain conditions the azimuthally magnetized circular ferrite and ferrite-dielectric waveguides, operating in the normal 01 TE mode, might produce differential phase shift [1-3]...
    • ...The computation of this quantity, of use in the development of digital phase shifters for electronically scanned antenna arrays, based on the geometries mentioned, is a complicated mathematical task [1-11]...

    M. N. Georgieva-Grosseet al. Numerical results for the differential phase shift in the circular wav...

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