Excitation of quasi-monochromotic waves by a high-voltage pulse in a ferrite coaxial line with the periodic structure

TL;DR

This paper demonstrates the excitation of narrowband gigahertz waves in a ferrite-filled coaxial line using high-voltage pulses, supported by experimental data and numerical simulations, achieving significant power and specific frequency ranges.

Contribution

It introduces a method for exciting weakly damped electromagnetic waves in ferrite coaxial structures with high-voltage pulses, combining experimental and simulation approaches.

Findings

Excited waves had frequencies between 1.89 GHz and 2.1 GHz.

Bandwidth of the excited waves was approximately 16%.

Output power reached about 20 MW at VHF frequencies.

Abstract

Experimental data and results of numerical simulations are presented, concerning excitation of narrowband gigahertz-range wave trains in coaxial guiding structures that are partially filled with ferromagnetic material and may involve periodically arranged metal inserts. The experiments performed confirm the possibility of exciting weakly damped electromagnetic waves by feeding high voltage, unilateral electromagnetic pulses of short duration into the line. The coax line was of outer diameter 50.5 mm, filled with an isotropic dielectric (relative dielectric constant {\epsilon} = 2.25) and a set of ferrite rings with {\epsilon}=16 and saturated-state {\mu} about 4 to 5. With a peak voltage of the primary pulse close to 160 kV and a magnetizing field of 17.5 kA/m, the parameters of the waves excited reached magnitudes as: frequency 1.89 GHz to 2.1 GHz; bandwidth 16%; VHF power at the output about 20 MW.