[FEKO problem]How to assign feed to a spring antenna?

Hi guys,

I have been trying to model a spring antenna and I am quite confused about how to add a feed to it. What kind of port should I use? Please shed some lights on it. Thanks!

What the *#@S is a spring antenna?

Not sure what a spring antenna is. Please provide a reference or picture.

By any means do you refer Helical antenna as Spring antenna ?
Please provide Picture or any reference paper for clarification.