fdtd source introduction

hello everybody,

I have a problem. I am not able to introduce diverging or converging beam in FDTD calculation domain. Is it possible to introduce diverging or conversing beam in FDTD by TF/SF formulation? If possible, how? People have used some ways to introduce such fields like using a lens to focus plane wave or arranging the sources in arc shape surface, but neither did I find what method they are using TF/SF or only scattered field formulation nor how they are modifying the source.
Please tell me how to introduce such fields?

thanks,

ravi

you must refer to ebook about FDTD for electromagnetic by kunz
https://www.edaboard.com/viewtopic.php?t=149266

hello,

I sent you a mail. perhaps you did not find that.
i did not get the book at the given url link.
can you have any other link?

thanks
ravi

Hello
electromagnetic simulation FDTD by sullivan
https://www.edaboard.com/viewtopic.php?t=74057

FDTD for electromagnetic by kunz
https://www.edaboard.com/viewtopic.php?t=149266