Computer evaluation of equivalent circuit of coplanar waveguide T-junction

For some of its advantages, the coplanar waveguide (CPW) is preferred to the microstrip line in developing monolithic microwave integrated circuits (MMICs) on GaAs and InP. However, due to lack of powerful design software, the potentials of this line have not been fully exploited. A computer package for efficient design of a CPW circuit should contain information on the equivalent circuits of various components including bends, open and short terminations, steps etc. This paper introduces a computer technique for the determination of the equivalent circuit of the CPW-T-junction. It can be extended to find the equivalent circuits of CPW bends, terminations, steps etc. The T-junction is particularly important as it is used in the biasing of the active devices as well as in matching methods employing stubs