Calculation and analysis of ACPW and UWB ACPW-slotline transition

The paper calculated the dispersion characteristic of asymmetrical coplanar waveguide (ACPW) using FDTD method. The results of theoretical calculation show very good agreement with XFDTD formulation and experimental data over a wide frequency range. And the time of the FDTD calculation is about one fourth of XFDTD formulation. On this basis, a novel approach for designing a UWB ACPW to slotline transition is presented. A slotline hollow patch creates open circuit conditions on one arm of the ACPW and resonates the transition so that maximum power transfer may occur. The S-parameters of ACPW-Slotline transition was calculated using FDTD method based on Mur-PML absorbing boundary condition. The results agree well with available theoretical and experimental data over a wide frequency range. It is shown that ACPW is easier to connect with slotline in circuit structure and impendence match compare with symmetrical CPW.