Development of Slim Rectangular Microspeaker Used for Minimultimedia Phones

For the recent multimedia capabilities, mobile phones of today need wider and thinner liquid crystal displays (LCDs) and smaller microspeakers with high acoustic performance. For a microspeaker, oval or rectangular configurations are preferable for better space utilization. However, size reduction is often limited by the magnetic circuit. Therefore, in this paper, a new configuration of magnetic circuit is introduced to reduce the widthwise size of the microspeaker. Comparison of magnetic forces between conventional and proposed magnetic circuit is carried out using 3-D finite-element method (FEM) analysis. Simulated results of sound pressure level (SPL) obtained by mechanical and acoustic analysis are also compared with experimental results. In conclusion, the microspeaker proposed in this paper has shorter widthwise length, more competitive price, and higher performance when compared to the conventional type