A Novel Dual-Band Power Divider With Controllable Power Ratio and Phase Difference

In this paper, a novel unequal dual-band power divider (PD) with three standard 50- $\Omega $ ports is presented. It consists of a resistor and eight transmission lines (TLs) with the same electrical length, where two cascaded transmission lines are newly bridged between two output ports. The constraint conditions of topology are established by analyzing the voltages and currents of each branch. Two types of the unequal dual-band PD with different phase difference ( $\varphi $ ) at output ports are selected for verification, where $\varphi = 0^{\mathrm {o}}$ in type I and $\varphi = 45^{\mathrm {o}}$ in type II. From the design charts and several design examples, the proposed PD could not only provide flexible power ratio ( $k^{2}$ ) at two operating frequencies but also adjust their operating frequency ratio ( $\mu $ ) and phase difference ( $\varphi $ ) between two output ports independently. Finally, an unequal dual-band PD with $k^{2} =3$ and $\varphi =$ – 45° is fabricated. Good agreement between the simulated results and measured results validates the correctness of the proposed design approach.