Studies of nanometer antennas incorporating gain material using CST

CST is a general purpose, computational electromagnetics simulation tool that uses the finite integration technique for its time domain solver. Unfortunately, it does not allow negative ε" data to be input by a user in the menu window. Consequently, the time domain solver of the current CST version cannot be used to solve the original negative ε" problem. Here we introduce a manual method to analyze a nanometer-sized active coated particle (CNP) problem using CST\´s frequency domain solver. Comparisons between these frequency domain simulation results with known analytical values show good agreement.