. The Bell System technical journal . WAVE PROPAGATION TIlKuUCill GYllOMAGNETIC MEDIA. II 941 An example of a simple non-reciprocal system is indicated in Fig. 1(a).Here a slab of ferrite is inserted into a rectangular waveguide parallelto the narrow walls and closer to one of them. Several workers havedemonstrated that this arrangement and a similar arrangement in acircular waveguide are non-reciprocal for what is essentially the dom-inant mode. When the slab is centered in the guide we have a planeof symmetry and the non-reciprocity vanishes. Another configuration of the transverse field typ
. The Bell System technical journal . WAVE PROPAGATION TIlKuUCill GYllOMAGNETIC MEDIA. II 941 An example of a simple non-reciprocal system is indicated in Fig. 1(a).Here a slab of ferrite is inserted into a rectangular waveguide parallelto the narrow walls and closer to one of them. Several workers havedemonstrated that this arrangement and a similar arrangement in acircular waveguide are non-reciprocal for what is essentially the dom-inant mode. When the slab is centered in the guide we have a planeof symmetry and the non-reciprocity vanishes. Another configuration of the transverse field type is represented bythe system shown in Fig. 1(b). Here a hollow ferrite cylinder is mag-netized circumferentially and propagates a TEon-mode. It is clear thatany arrangement of this sort, which might, in principle, include conduct-ing sheaths, internally or externally, or might have the ferrite extendingto an indefinitely large or small radius, cannot have any symmetry MAGNETIZINGFIELD Ho WAVEGUIDE ~ WINDINGS FORMAGNETIZING--,CURRENT. PROPAGATIONDIRECTION CIRCUMFERENTIAL,-MAGNETIC FIELD (b) Fig. 1 — (a) Rectangular waveguide and ferrite slab, (b) Circumferentiallymagnetized ferrite cylinder. * It is expected that an article on this subject by S. E. Miller, A. G. Fox andM. T. Weiss will appear in a forthcoming issue of the Journal. 942 THE BELL SYSTEM TECHNICAL JOURNAL, JULY 1954 about a cylinder coaxial with the ferrite. Thus, the internal and externalimpedances of such a system at any coaxial cylinder can only com-pensate accidentally (perhaps at a single frequency) and non-reciprocityis the rule. It is freciuently asserted without ciualification that for non-reciprocitya further condition upon the relevant rf field is that its projection upon aplane normal to the magnetizing field be elliptically or circularly polar-ized in the limit of vanishing magnetization. The argument is based onthe consideration, in itself correct, that the effective material constantsare different f
Size: 1465px × 1706px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
