Design of a Harmonic Rejection Microstrip Low-Pass Filter with Defected-Ground using Finite-Difference Time-Domain and Optimization Algorithms

In this paper, a non-uniform finite-difference time-domain (FDTD) method is incorporated with a design-sensitivity optimization technique to design a harmonic rejection microstrip low-pass filter (LPF) with defected ground. The proposed LPF features a defected ground plane to obtain high impedance on the microstrip line and perform a broad harmonic rejection. The design process initializes with the application of a developed FDTD solver to study the geometric parameters for filter analysis. The optimization technique modifies the parameter values and the structure is analyzed again until the performance meets the specified requirement