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The conditions for the optimal non-reciprocal operation of longitudinally magnetised ferrite-coupled line (FCL) are obtained for the first time from the scattering-matrix treatment, and the necessary conditions for the multicomponent reciprocal network joint with a FCL section to be a circulator are specified. Using these optimal conditions, the minimum length of the FCL is also found. A self-biasing circulator with the minimum length of FCL at millimetre-wave frequency is reported and its scattering characteristics are simulated and discussed. [ABSTRACT FROM AUTHOR]

In this paper, a nonreciprocal left-handed transmission line has been investigated. It is composed of a normally magnetised ferrite microstripline periodically loaded with lumped capacitances and inductive stubs. Based on the simple equivalent circuit model for a predominant edge guided mode, the dispersion relation of the ferrite left-handed transmission line has been estimated, providing the backward wave characteristic in the positive and negative permeability frequency regions. With the aid of the finite element method, it is confirmed that specific three-dimensional structures do show left-handed characteristics as well as the nonreciprocity. Nonreciprocal transmission characteristics with the isolation of more than 30 dB are obtained numerically and demonstrated experimentally in the positive and negative permeability frequency regions, for the edge guided modes. It is explained that the nonreciprocity of the ferrite left-handed transmission line is caused by the leaky wave phenomenon from the microstrip to the ferrite substrate. [ABSTRACT FROM AUTHOR]

In a gapped inductor, airgap fringing flux induces eddy currents in coil conductors in the vicinity of the airgap, producing unwanted power loss and heat in the coil. An open-circuit copper screen placed around the airgap of a ferrite core is shown to reduce the fringing flux around the airgap. The reduction in fringing flux is shown by experiment to reduce the power loss, in the inductor winding, associated with eddy currents induced by airgap fringing flux, and practical results compare favourably with presented finite-element results. The reduction in coil losses reduces the cooling requirement for the inductor, or alternatively, allows an increase in the thermal rating of the inductor. [ABSTRACT FROM AUTHOR]

A novel electrically and magnetically tunable microwave phase shifter based on forward volume spin wave propagation in a layered structure containing films of oriented barium ferrite (BaM) and polycrystalline ferroelectric barium strontium titanate (BSTO) is proposed. Operating characteristics of the phase shifter are theoretically investigated. It is shown that the hexaferrite-ferroelectric waveguiding element allows the construction of compact devices with high electrical tunability and operation frequency up to ∼0.1 THz at reasonable bias magnetic fields. [ABSTRACT FROM AUTHOR]