Practical Constraints on Nonlinear Transmission Lines for RF Generation

Previous research has shown the applicability of nonlinear transmission lines (NLTLs) in high speed and wide bandwidth systems. These applications involve techniques for forming and sharpening a short electrical pulse to achieve pulse compressors, frequency multipliers, phase shifters, and, in addition, radio frequency (RF) generation, holding, in this case, a great potential for replacing vacuum electron tubes with a low cost and fully solid-state technology. Based on the analysis of relevant experimental results of different types of NLTLs reported in the literature, this paper presents an investigation about the correlation between the performance limits of NLTLs and specific characteristics of the materials used in their construction, concluding that there is a pressing demand for the development of high-performance dielectric and magnetic materials with special characteristics such as highly nonlinear behavior, low losses at microwave frequencies, and thermal stability that would allow for an improvement in the performance of NLTLs, enabling their operation at higher frequencies and with better electrical-to-RF conversion efficiency. The achievement of a stable behavior over a broader operating temperature range would allow the application of NLTLs in military and aerospace devices.