The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 2000
Filed:
Feb. 20, 1998
Gerald F Dionne, Winchester, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
In a ferrite switchable microwave device, a magnetic structure is formed in a nearly continuous closed-loop configuration of a single crystal material, or of a material exhibiting the magnetic properties of single crystal materials (quasi-single crystal materials). A magnetization M is induced in the structure. The toroidal shape of the structure in combination with the properties of the magnetic material results in a device which exhibits virtually no hysteresis. The device is operable either in a fully magnetized state or in a partially magnetized state. In a fully magnetized state, the device operates in the region of magnetic saturation. The absence of hysteresis in the device enables switching between the positive and negative magnetic saturation points with very little energy. In a partially magnetized state, the device provides a variable magnetization M between the two saturation points. The magnetization curve is made linear and therefore controllable by introducing a gap or other demagnetizing feature in the magnetic structure. This device is particularly operable as a variable phase shifter or tunable filter where the magnetization controls the velocity of electromagnetic energy propagating in the magnetic device.