Three-axis magnetometers using spin-dependent tunneling: reduced size and power

A 3-axis magnetometer has been constructed using 3 Spin Dependent Tunneling (SDT) magnetic field sensors as transducers. This magnetometer has been designed for use in Unattended Ground Sensor (UGS) applications. As such, there has been an emphasis on low cost, size, and power. The present version is smaller than previous versions, and is ready for prototype sampling. This paper describes the basic properties of the SDT 3-axis magnetometer, including size, power, and noise floor.