Wideband and Compact Wilkinson Power Divider Utilizing Series Delta-Stub and Folded Stepped-Impedance Transmission Line

In this paper, a Wilkinson power divider is modified using four-series delta-stub and folded stepped-impedance transmission line (FSITL) in order to achieve a reduced circuit size of 84% and fractional bandwidth of 116%. Series delta-stubs are used instead of open shunt stubs to obtain an optimum shifting frequency and wider bandwidth. Folded stepped-impedance transmission line (FSITL) is used to achieve reduced circuit size. The proposed power divider is fabricated using RT/duroid 5880 substrate with thickness of 0.38 mm. The dimension of the power divider is 13 mm × 6.5 mm. The proposed power divider has typical power division of -3 dB and insertion loss less than -1 dB, better than -13 dB of isolation, less than -10 dB return loss and phase imbalances less than 2° from 1.5 to 3 GHz. Both simulation and measurement results show a good agreement.