A Micromechanical Cantilever Magnetic Field Sensor And The Resonat Cantilever Electromagnetic Exciting Technique

This paper is meanly devided into four chapters. The first chapter summarize the MEMS and bring out the work of this thesis. The second chapter focus on a new micro machined self-calibrated magnetic-field sensor, with aspects of design, fabrication and test. The third chapter meanly discuss the principle of the electromagnetic drving technique, meanwhile develop a closed-loop circuit for resonator sensors and give out the design and test of the AGC style closed-loop circuit.In the second chapter, a brand new kind of static cantilever magnitude field metrical sensor with self-calibrated function based on MEMS technology is designed and fabricated. The cantilever is excited by magnetic force, detected with pizeo-resisitence and utilizes circles of aluminum to achieve self-calibrated function. Both the detection and the self-calibrated are integrated on a single chip. A minimum magnitude field sensitivity of 2.7313μT has been achieved in the atmosphere condition.In the following chapter, the mechanics and electrics model of the MEMS resonator is bring forward. With analysis of Barkhausen oscillate rule, a AGC style of closed-loop circuit is used to analysis the resonator's stability. The internal frame of the circuit has been analyszed and proved. A best frequency stability of 1Hz and a best mass sensing resolution of 0.3 pg is provided.At the end of every chapter, there is a brief narrate of the deficiency and further work.In the end, all the thesis contents have been summarized.