MEMS Flux Concentrator: A Device for Minimizing 1/f Noise in Magnetic Sensors

摘要

Magnetic sensors typically have a considerable amount of 1/f noise that limits their performance in detecting slow-moving military vehicles. Here we describe a Micro Electro-Mechanical Systems (MEMS) flux concentrator, which is a new device that can minimize 1/f noise in magnetic sensors by modulating the magnetic field at the position of the sensor. The modulation is accomplished by a periodic motion of flux concentrators on each side of the magnetic sensor. Modulating the sensor field shifts the operating frequency to higher frequencies where the 1/f noise can be one or two orders of magnitude smaller. We will also present magnetic and mechanical modeling results on a design that will operate at 29 kHz.