Composite structured piezomagnetometer
First Claim
1. A magnetic and electric field sensor and measurement apparatus comprising a composite structure having alternatingly secured plural piezoelectric material layers and magnetostrictive material layers, magnets positioned adjacent to the composite structure for supplying a bias field to the composite structure, and a measurement circuit connected to the piezoelectric layers for measuring output of the piezoelectric layers in the composite structure.
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Accused Products
Abstract
A piezomagnetometer uses a magnetoelectric composite structure, formed by alternating layers of piezoelectric and magnetostrictive material, to convert a fluctuating magnetic field directly to electric current. Strain in the magnetostrictive layers, coming from an ambient magnetic field, stresses piezoelectric layers and drives a polarization current proportional to amplitude of the ambient field. Electrically, the composite is a current source connected in parallel with a capacitor. Its simple and direct operation and solid state sensor enables constructing a small, rugged, inexpensive magnetometer that operates at an ambient temperature with high sensitivity at low power. Multiple piezomagnetometers can be incorporated into a practical detection system capable of operating at ambient temperatures and meeting the limitations presented in civilian and military operations.
52 Citations
22 Claims
- 1. A magnetic and electric field sensor and measurement apparatus comprising a composite structure having alternatingly secured plural piezoelectric material layers and magnetostrictive material layers, magnets positioned adjacent to the composite structure for supplying a bias field to the composite structure, and a measurement circuit connected to the piezoelectric layers for measuring output of the piezoelectric layers in the composite structure.
- 16. A magnetic and electric field sensor and measurement apparatus comprising multiple composite structures, each composite structure having alternatingly secured piezoelectric material layers and magnetostrictive material layers, and a measurement circuit connected to the piezoelectric layers for measuring output of the piezoelectric layers in the composite structures.
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22. A method for sensing and measuring magnetic and electric fields comprising the steps of straining plural magnetostrictive layers by a applying magnetic field thereby stressing and polarizing alternately placed plural piezoelectric layers for generating a current across the layers, and measuring the current by a detector.
Specification