Device including ferrimagnetic coupling element
AssigneeMicrowave and Electronic Systems Limited
InventorsRobert D. Pringle, Ian F. Morton
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Abstract
A radio frequency coupling device has a non-magnetic, dielectric substrate having a planar surface on which a ferrimagnetic disc-shaped film is epitaxially grown. Sections of surface-oriented transmission line such as coplanar waveguide or slot-line extend over the substrate surface and terminate over the disc. The ferrimagnetic material couples to the RF magnetic fields associated with the transmission line sections and provides a coupling therebetween which is tunable by adjusting a direct magnetic field applied to the disc. Low direct coupling between the sections is obtained by arranging their respective RF magnetic fields to be orthogonal at the disc.
Claims16
A radio frequency coupling device comprising a non-magnetic, dielectric, single crystal substrate;
- a film of single crystal ferrimagnetic material epitaxial with said substrate and located at a substrate surface essentially co-planar therewith;
- first and second surface-oriented transmission line sections formed on said substrate surface and having respective end portions thereof overlying said ferrimagnetic film, said film of ferrimagnetic material when subjected to a biasing direct magnetic field serving to couple the magnetic fields of such first and second surface-oriented transmission line sections, said end portions being terminated to present an RF discontinuity therebetween which prevents significant mutual coupling directly between said first and second transmission line sections, and said end portions cooperating with said ferrimagnetic film in the presence of said biasing magnetic field to couple thereto and establish a reciprocal RF coupling between said first and second transmission line sections at a frequency dependent on said biasing magnetic field.
A radio frequency coupling device comprising a non-magnetic, dielectric, single crystal substrate;
- a film of single crystal ferrimagnetic material epitaxial with said substrate and disposed at a portion of a surface of said substrate essentially coplanar therewith;
- a layer of patterned metallisation overlying said substrate surface and said film, said metallisation being patterned to define a first surface-oriented transmission line section partially extending over said substrate surface and having a terminating portion overlying said film, and a second surface-oriented transmission line section partially extending over said substrate surface and having a terminating portion overlying said film, an RF discontinuity existing between said terminating portions to prevent significant mutal coupling directly therebetween;
- said ferrimagnetic film when subjected to a biasing direct magnetic field serving to establish a reciprocal RF coupling through said film between said terminating portions of said transmission line sections at a frequency dependent on said biasing magnetic field.
Dependencies are inferred from the claim text.