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In recent years, there has been great interest in the study of nonlinear transmission lines (NLTLs) for high-power radio frequency (RF) generation. The periodicity of the NLTL accounts for dispersion effects, whereas its nonlinear elements (inductors and/or capacitors) are responsible for the nonlinear processes. Both of these mechanisms acting simultaneously on a propagating pulse allow the generation of high-frequency oscillations at the output. The objective of this paper is to study the quantifiable characteristics of these lines for RF generation by means of SPICE circuit simulation and on basis of experiments. The RF generation at 40 MHz is demonstrated through measurement of the fast Fourier transform of the RF signal extracted at the load and by comparison with the corresponding simulated spectrum. It is expected that the technique presented here can be useful for the design of NLTLs to drive compact RF antennas for space applications and defense mobile platforms. [ABSTRACT FROM PUBLISHER]

Low loss dielectric materials with high permittivity and nonlinear behavior are essential for use in capacitive nonlinear transmission lines (NLTLs) for RF generation. NLTLs have a great potential to generate soliton waves for high-power microwave applications in mobile defense platforms and satellite communications. In this paper, the dielectric properties of a piezoelectric capacitor based on lead-zirconate-titanate (PZT) was characterized in a broadband frequency range from 10 MHz to 1 GHz for use in NLTLs. Three commercial ceramic capacitors made of barium titanate (BaTiO3) were also assessed for comparison with the PZT capacitor. The characterization of materials consisted of measuring the relative dielectric constant (real and imaginary parts) as function of the applied voltage and frequency to calculate the loss tangent of the material. The results showed that PZT material has a better performance for use in NLTLs than barium titanate because of its lower losses. As discussed here, however, the use of PZT and barium titanate-based materials in NLTLs are compromised by the self-resonant frequency of the capacitors because of the inherent parasitic inductance associated with the capacitor at high frequencies. [ABSTRACT FROM PUBLISHER]

A nonlinear lumped element transmission line (NLETL) that comprises an $LC$ -ladder network where either the capacitors or inductors are nonlinear is used to convert an input rectangular pulse to a series of RF pulses at the output. This paper describes the implementation and demonstration of a high-voltage nonlinear hybrid line (NLHL) where both the line components (inductors and capacitors) are nonlinear. Lines with only one nonlinear component have been described in numerous publications in simulation and experiment whereas an NLHL has been described in only a few papers in simulation. There is no report about NLHL being tested to-date according to the best of our knowledge. We have built and tested an NLHL using commercial-off-the-shelf components. Instead of using complex pulse forming networks or pulse forming lines, a storage capacitor and a fast semiconductor switch are used to provide an input pulse with good approximation of a rectangular pulse shape. The experimental results are compared with simulations predicted by the in-house developed nonlinear lumped element transmission line (NLETL) circuit model. Analyses on the voltage modulation and frequency content of the output pulses are carried out. The conditions for producing RF pulses in NLHL and its performance are discussed. [ABSTRACT FROM PUBLISHER]