Design and Analysis of Quad-Band Wilkinson Power Divider

In this paper, the design of equal-split quad-band Wilkinson power divider is presented. The design consists of two quad-band transmission line transformers and four isolation resistors. Standard transmission line theory and even/odd modes analyses are used to obtain closed form expressions that are solved using particle swarm optimization technique to find the required divider parameters (lengths, characteristic impedances, and isolation resistors). Very good matching at all ports and isolation between the output ports are achieved at four arbitrary frequencies. To validate the design approach and the derived equations, a quad-band microstrip line Wilkinson divider is designed, analyzed, and measured.