Abstract: We present the analysis of some Photonic Band Gap(PBG) structures in microstrip transmission lines by using the Modified Locally conformal Finite Difference Time Domain(MLC-FDTD) Method. Numerical results show that better numerical accuracy can be achieved using this method. The analysis is made to study the influence of the period pattern and the radius of holes etched in the ground plane on the S parameters. Numerical results show that the period pattern determines the central frequency and that the redius of holes influences the width and the depth of the forbidden band.

Key words: modified locally conformal finite difference time domain(FDTD), photonic band gap, microstrip line