Excitation of modal fields in parallel-plate transmission line

In this report we discuss the problem of source radiation in an open, parallel-plate waveguide of finite width. Such a structure is used as a simulator for testing EMP hardening of large systems such as aircrafts. A conventional approach to expanding the fields in an open waveguide of this type entails the use of the leaky-mode representation. Such a representation is an approximate one and, under certain situations, it is desirable to verify its accuracy. The solution derived in this report is a complete one and can be used to test the leaky mode representation.