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.