Fu Shiqiang

Analysis of Characteristic Impedance of Asymmetrical Coplanar Waveguide using Multi-resolution Time Domain Method

The characteristic impedance of asymmetrical coplanar waveguide (ACPW) was calculated using multi-resolution time domain (MRTD) method which based on Daubechies compactly supported scaling functions. The good agreement between this paper and the conventional FDTD method was obtained. Efficiency of MRTD method was compared with FDTD method. Time and frequency domain results have been presented and explained. The curves of characteristic impedance varying with frequency were drawn from 1GHz to 60GHz. The effect of side strip width on characteristic impedance was analyzed.

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.

Design of a novel antenna element for BGAN phased array antenna system

A novel antenna element has been proposed for maritime satellite communication Broadband Global Area Network (BGAN) phased array antenna system. The proposed antenna element is composed of a square radiating patch, two vertical trapezoidal coupling strips and a T-junction power splitter feeding network. A dual orthogonal side coupled feeding technique has been adopted to realize a circularly polarized square patch antenna. Design concepts and procedures are introduced, followed by simulations and discussions. Good antenna characteristics are achieved in the entire BGAN working band, having input impedance match characteristics of S11<;-15dB, antenna gain higher than 7dBi, and the axial ratio lower than 4dB.