The directivity gain and the input impedance of a circular loop are
computed.
The loop sits in the x-y plane.
Specify the frequency (in MHZ) at which the antenna will operate, the radius
of the loop (in meters) and the radius "wirad" of the wire (in
millimeters).
This script was developed at the Center for Computational Electromagnetics (CCEM)
in the University of Illinois at Urbana with funding from the Sloan Center
for Asynchronous Learning Environments(SCALE).