Wideband Tuning of Impedance Matching Networks using Hierarchical Genetic Algorithms for Multistandard Mobile Communications

An adaptive technique adopting hierarchical genetic algorithms (HGA) for wideband antenna impedance tuning is presented in the paper. Three simulation examples are given for GSM, UMTS and both standards, with different types of antenna impedance. The frequency range of the dual standards is from 1.7 to 2.2GHz. Simulation results show that the proposed tuning technique can achieve good accuracy of impedance matching and load power. The reflection coefficient and VSWR obtained are also very close to their ideal values. Comparison of the proposed HGA tuning method with conventional genetic algorithm based tuning method is also given, which shows that the HGA tuning algorithm is much faster. Moreover, the proposed method can be useful for software defined radio systems using a single antenna for multiple mobile and wireless bands. .