Synthesis method and tapering rule choice for tapered nonlinear transmission lines

Tapered NLTLs are very interesting for pulse‐compression applications. They allow metallic losses to be minimized and need fewer diodes than classical NLTLs. But their design is not easy due to the choice of the input Bragg frequency and the tapering rule. This Letter proposes a systematic method where input and output Bragg frequencies are automatically fixed. The importance of the tapering rule is also shown. Linear tapering gives better results than geometric. For the same number of diodes, output fall time is smaller and the NLTL is shorter for the same amplitude. The systematic method is applied with linear tapering to GaAs NLTL designed for pulse compression from 16 to 2 ps and shows a great improvement in the output amplitude (more than 50%). The present results are based on SPICE simulations, including diode and linear transmission line dc metallic losses. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 33: 68–71, 2002