Excitation Issues and Feeding Models

The consistent advancement of electromagnetic fields in antenna problems is firmly connected to the incident wave source settings imposed at the beginning of every simulation. As a matter of fact, these settings act like a connecting link between continuous and discrete state, since 

The appropriate excitation scheme depends upon the particular FDTD setup. For illustration, when the antenna points at which reflections originate are to be found, a narrow Gaussian pulse could be the most preferable solution. Thus, for a transmitting antenna, the incident voltage in the feeding line is given by 

On the other hand, when broadband investigations are required, it is more effective to use a differentiated signal and then use the Fourier transform to derive the desired response in the frequency domain. In this case, the corresponding Gaussian pulse becomes 

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