100-MW-Level Experiments of a Gyromagnetic Nonlinear Transmission Line System

The wideband high-power microwave systems have the advantages of wide energy spectrum, electron beam independence, compactness, and low cost. The gyromagnetic nonlinear transmission line (GNLTL) has drawn much attention for its potential as a novel solid-state, frequency-agile, and compact wideband source. The working mechanism of GNLTL is different from that of the traditional electric vacuum tubes, and the strong dispersion and nonlinear characteristics make it difficult to be accurately theoretically calculated and simulated. In this article, a 100-MW-level GNLTL system based on a Tesla-type driver was designed and constructed. A series of test experiments were then carried out to investigate the effects of different configurations, including delay line length, ferrite cores’ assembly orientation, transmission line length, bias magnetic field magnitude, and excitation voltage. The changing laws of the key parameters of the output microwaves including the peak power, modulation depth, center frequency, and percentage band are summarized and the underlying physical mechanisms are analyzed. The results may be instructive for the predesign of GNLTLs, especially for the devices operating at high power. In addition, a multiple center frequency points’ phenomenon was discovered in the output signal, which may bring new application possibilities for GNLTL.