Millimeter wave tunable power divider using modified Wilkinson design

A variable power divider operating at the millimeter wave band using a modified Wilkinson structure is proposed. It is designed to operate at the millimeter wave band (28 GHz), which is proposed for 5G mobile systems. The power divider consists of conventional Wilkinson power divider but the two branches of the input T-junction are substituted by coupled-lines. Between each coupled - lines, there is a varactor to tune the coupling factor and thus the output power. Two open-ended stubs, connected to the output ports and a chip resister are used to enhance the output matching and the isolation, respectively. The proposed design has a compact size and range of simulated power division that varies from 1:1 to 1:2 through a frequency range from 27 to 29 GHz. The return loss and isolation between the outputs are more than 10 dB across the band and tuning range.