Analysis of characteristic impedance of asymmetric coplanar waveguide using finite-difference time-domain method

The paper presents a detailed analysis of characteristic impedance of asymmetric coplanar waveguide (ACPW) using the finite-difference time-domain (FDTD) method, and the results agree well with available theoretical and experimental data over a wide frequency range. The transient propagating waveforms along the ACPW, which are excited by retarded Gaussian pulse, are found in the time domain. After the time-domain field distributions are obtained, frequency-domain parameters such as the characteristic impedance are calculated using Fourier transformations. Index Terms-Asymmetric coplanar waveguide (ACPW),Finite-difference time-domain (FDTD) method,Absorb boundary condition,Characteristic impedance