The Effect of Quasi-Chaotic Oscillations Formation in Devices Based on Strip Structures Containing Bulk LiNbO3 Crystals

The results of an experimental study of modules based on strip lines with two layers of dielectric media have been presented in the work. The first layer is a substrate of an FR4 foil material, and the second layer is a bulk lithium niobate crystal. The frequency characteristics of modules made based on three types of strip structures in the form of a coplanar line with a grounded base, SIW-type strip line, and an asymmetrical strip line with a perforated substrate were measured. The lithium niobate crystal was 24×18×39 mm. The crystal was placed on the surface of the strip lines on the side of the current-carrying strip on the XZ plane. The measurements were taken under the influence of an LFM signal in the ultra-wide frequency band ranging from 10 MHz to 26 GHz, as well as when a pulse in the form of a step was applied to the input of the modules. The emergence of microwave quasi-chaotic oscillations in the modules based on the strip lines of three different designs was detected. The effect wasobserved both under the influence of an LFM signal and in the pulse exposure mode. The experimental results show the possibility of constructing devices to form quasi-chaotic signals in the microwave range with characteristics that depend on the type of the strip line structure.