Characterization of a single-step microstrip discontinuity in a substrate using the finite-difference time-domain method

A single-step microstrip discontinuity in a substrate is characterized usin g the finite-difference time-domain (FDTD) method, and an equivalent circui t model has been developed. The microstrip discontinuity newly introduced i n this paper has a substrate thickness change in the longitudinal direction with a uniform strip width. The discontinuity has applications in patch an tenna Seed design and interconnections between microwave circuit modules. T he simulation results are compared with those computed by HFSS to show good agreement. An equivalent circuit developed from the FDTD results, which is accurate within 2.4% in magnitudes of S-11 and S-21, can be applied for co mputer aided designs. (C) 2000 John Wiley & Sons, Inc.