Global optimization method of the design for multi-layer planar inductors

A global optimization method is presented to optimize the multi-layer planar inductors. The essential idea of the algorithm is as follows. Based on the proposed physical model, acquiring the maximum quality factor is considered as design objective, and frequency, inductance in unit area and current handling capability are regarded as constraints, hence the designed problem is formulized as the posynomial functions of the physical dimensions of inductors, i.e. the optimum problem can be equivalent to geometric programming so as to quickly obtain optimization result under different conditions. From the measurement results of the inductors designed by the method, the maximum error between the measured quality factor and the optimized results is less than 10% under the restrictions where the inductance in unit area is greater than 80 mH per square meter, metal width is no less than 10 millimeter and frequency band is 50-400 MHz.