Coupling analysis of multiple linear antennas fed by coaxial lines on electronic system with a time domain hybrid method

Due to the shielding structures of electronic system and coaxial lines feeding the antennas are complex, full-wave algorithms applied for the coupling analysis of multiple linear antennas on electronic system excited by ambient wave should occupy amount of memories by meshing the structures of coaxial lines and electronic system in fine grid, which may affect the computation efficiency. This paper presents a time domain hybrid method, which consisting of thin wire finite-difference time domain (FDTD) method, transmission line (TL) equations, higher order FDTD scheme, and an auto mesh generator technique. In this method, the thin wire FDTD combined with the auto mesh generator technique is utilized to mesh the shielding structure of electronic system rapidly and obtain the current responses on the conductor columns of linear antennas, which are extracted equivalent current sources for the further coupling analysis of coaxial lines. And then the TL equations are adopted to build the coupling models of coaxial lines, and solved by the higher order FDTD scheme to compute the transient responses on the coaxial lines and terminal loads of the lines. This method has one significant feature is that it can avoid modeling the structures of linear antennas and coaxial lines directly. The accuracy of this method has been verified by comparing with the simulation software Computer Simulation Technology (CST) via the coupling simulations of one and three linear antennas on electronic system excited by ambient plane wave.