Fixed frequency filters using epitaxial ferrite films
AssigneeRockwell International Corporation
InventorWayne L. Bongianni
Life of this patent
Estimating the term…
Abstract
Films of epitaxially deposited hexagonal ferrite material backed with metal and inserted into waveguides in single and multiple stages are used to form band-pass and band-stop filters, variable attenuators and modulators. The films have body resonance modes with resonant frequencies which are essentially fixed as an externally applied magnetic field is varied. Thin films of hexagonal ferrite material have resonant frequencies in the high microwave and millimeter wavelength frequency ranges. Since hexagonal ferrites have a high magnetic anisotropy and accompanying high internal magnetic field, little or no external magnetic bias may be required once the film is magnetized.
Claims13
A filter for electromagnetic waves comprising:
- a wave guide;
- a thin film of monocrystalline hexagonal ferrite disposed within said wave guide normal to the direction of propagation of radiant energy therein, wherein said thin ferrite film is epitaxially deposited on a single crystal substrate;
- and
- conductive means for reflecting radiant energy incident on and transmitted through said thin ferrite film back through said thin ferrite film.
A filter for electromagnetic waves, comprising:
- a wave guide;
- a thin film of a monocrystalline hexagonal ferrite disposed within said wave guide normal to the direction of propagation of radiant energy therein;
- conductive means for reflecting radiant energy incident on and transmitted through said thin ferrite film back through said thin ferrite film;
- and
- means external to said wave guide for applying a magnetic field to said thin ferrite film in the plane of said film.
Dependencies are inferred from the claim text.