Simulation of broadband double-ridged horn in high-fidelity material characterization using finite-difference time-domain method

To accurately characterize the double-ridged horn is very crucial to the design and improvement of the broadband free space material measurement. Based on traditional FDTD schemes, an improved boundary termination technique, re-radiating boundary condition (rRBC) and the PEC block modeling scheme were used to model the complex structures and to improve the simulation accuracy and efficiency. The approach was verified on regular pyramidal horn and extended to a double-ridged horn. Our results show significantly better consistency with the measurement data than numeric data provided by the manufacturer.