Anchor loss optimization for magnetic flux modulation structure of magnetoresistive sensor

Piezoelectric driven magnetic flux modulation is an effective method to suppress 1/f noise of magnetoresistive sensor, and obtaining a modulation structure with high quality factor (Q factor) is of great significance in improving the modulation performance. In this paper, influence of anchor positions on the Q factor was investigated with simulation and experiment methods. First, Q factor dependent on damping of each material was analyzed, and the upper limit for studying the anchor loss was given. The displacement and stress distributions of the ceramic substrate were also simulated, so as to indirectly guide the selection of anchor locations. Then a fixture was applied to investigate the Q factor under different clamped positions, and the results shows that the clamping condition does have a great effect on the Q factor, and the smaller the stress and displacement at the support are, the larger the Q factor is. Accordingly, the modulation structure was fixed to the package base in a diagonally fixed manner or short side centers fixed manner, and the maximal Q factor reached 920, which is much higher than that under other fixed manners.