Transient analysis of electromagnetic pulse coupling to normal mode helical antennas based on circuit models

The normal mode helical antenna (NMHA) is widely used for RF communication applications and usually provides a potential front door path of coupling electromagnetic pulse (EMP). Many numerical methods are employed to analyze the transient response of antennas under EMP, such as time-domain finite difference (FDTD) and time domain integral equation (TDIF) methods. While the numerical methods give accurate results, they can be time-consuming and only provide snapshots of EMP response in very specific circumstances. In addition, the transient data obtained from numerical tools is often required to be handled for the subsequent EMP vulnerability assessment in the RF front end circuits of communication system. The analysis of transient response for communication systems in the presence of EMP was usually complicated in the traditional field-circuit method.