First-pass success is important for cost-effective Monolithic Microwave and Millimeter-wave Integrated Circuits (MMMICs) since additional iterations to the MMMIC design are costly and take months to complete. In order to meet these goals, new levels of capabilities in the design, test and comprehensive simulations are required. The MMMICs employ microstrip line as a component connecting transmission medium as well as a distributed matching element. In a circuit layout, any deviation from straight transmission lines causes the introduction of discontinuity parasitics which must also be modeled as accurately as possible in order to predict the circuit performance. These discontinuities should either be taken into account or compensated for at the final stage of the design. A comparative study of different circuit simulators is undertaken to characterize microstrip discontinuities. Several microstrip discontinuities, such as bends, steps, and tees are examined and optimum compensated models are determined. / Master of Science