A Semi-Analytical Approach for Performance Evaluation of RTD-Based Oscillators

In this paper, it is presented a comprehensive analysis of three optoelectronic oscillators circuits based on resonant-tunneling diodes (RTD) for promising applications in terahertz frequency (THz) range. For all cases, it is investigated how each of these RTD devices performs under a wide range of the direct current (DC) voltages within the negative differential resistance region (NDR). The mathematical formalism developed here accounts for the effect of bias applied on the parameters of the reactive elements that composed the oscillators' small signal model. In this context, new expressions for evaluating the width of the depletion region of the devices are derived. Such mathematical formalism allows to make the performance analysis straightforward and show a close agreement to the device characterizations presented in the literature. Results pave the way for these RTD-based oscillators as potential candidates for Radio-over-Fiber (RoF) transmission, where higher operation frequencies will be major network requirements.