Impact of Bias Field Screening and Dipole Length in Terahertz Photoconductive Antennas

A numerical approach for the modelling of dipole Photoconductive Antennas (PCAs) is presented, based on the classical Drude model with extension to include the bias field screening due to both the space charge and the THz radiation fields. By employing a fixed-point iterative algorithm, good computational efficiency and convergence are obtained for typical PCA configuration parameters. Results unveiling the role played by each of the different phenomena and the radiated THz spectra for different dipole lengths are shown and discussed.