Terahertz technology has received continuously increasing attention in recent years. A key enabler of this technology is the photo-conductive antenna. A time-domain Norton equivalent circuit representing the antenna and a time-step algorithm provide the tools for analysis and design of such structures. However, the antenna impedance impulse response must be known beforehand. In this thesis, a more comprehensive characterization of the algorithm is provided through a detailed investigation. A numerical error in its output is discovered, the source of which identified, and an error minimization solution proposed. Using the newly acquired knowledge of the algorithm’s properties, an infinite photo-conductive slot is analyzed. First, a time-domain energy balance equation is derived using switched capacitor formalism, and verified. Then, a comparison to constant antenna impedance approximation is performed. A study on the frequency and time-domain far-fields, as well as, on the influence of parameters is also performed. Finally, the analysis is extended to a 1D connected array, in which the mutual coupling and performance are investigated.