Hybrid Wideband Microstrip Wilkinson Power Divider Based on Lowpass Filter Optimized Using Particle Swarm Method

Abstract

In this paper, an optimized microstrip hybrid 3-stage Wilkinson power divider based on lowpass filter is presented. The particle swarm optimization (PSO) method and method of moment (MoM) have been used to broaden the bandwidth to effectively cover 2–8 GHz ultra wideband range which is equal to 120% fractional bandwidth and to reject higher frequencies. The dimensions of filtering blocks and also Wilkinson isolating resistors are all used as optimization variables. The fitness function is evaluated by MOM simulations, and the MoM is used to calculate the response of the proposed Wilkinson power divider. A prototype hybrid power divider based on lowpass filter is then fabricated and measured to provide an experimental verification on the predicted features. Finally, both the method of moment and finite elements method are used to simulate the s-parameters. Simulation results on insertion loss and isolation of the implemented power divider are compared with measured values, and results for return loss is obtained using MoM and finite elements method.