Design considerations for diode-based nonlinear transmission lines

Diode-based nonlinear transmission lines (D-NLTL) are a class of pulse shaping networks capable of increasing the discrete spectral content of a pulse at high volumetric power density. However, a systematic design procedure for D-NLTLs is lacking, limiting their prototyping, evaluation, production, and adoption. To produce a D-NLTL design approach, parameters for UHF band (0.3–1 GHz) frequency generation are presented as a function of the input excitation pulse, network topology, and sub-components’ reactive value. Excitation pulse amplitude is found to have a strong effect on center frequency (fc), max frequency (fBragg), peak power (Ppeak), and RF power conversion efficiency (ηRF). In general, when cell inductance is decreased, both fc and signal propagation velocity are increased. The results are then presented as an example to design, build, test, and compare a 40-cell D-NLTL whose measured fc and fBragg are 256 and 446 MHz, respectively. Finally, we used the parameter space study results and empirical validation to present controllable waveform design rules-of-thumb.