Antenna circuit model for time-domain transient analysis

When pulse-generating circuits excite antennas, the antenna often plays a major role in determining the characteristics of the radiated signal. Defining an equivalent electrical circuit for the antenna allows the simulation of the antenna's transient behavior. This type of simulation, carried out with circuit analysis software, generates time-domain currents at different points on the antenna structure. From these currents, the time-domain radiated electric field can be calculated. This paper describes a procedure for developing a distributed RLC circuit model for a monopole antenna above a ground plane. The results from the modeling are compared to measurements of antenna current and radiated electric field.