Background. Creation of effective radiating structures operating in millimeter range is one of the important directions in modern microwave technology. The use of different hybrid metal-dielectric structures for this range becomes increasingly significant because of possible occurrence of certain physical effects, which are impossible in standard dielectric waveguides and structures on their basis.Objectives. Experimentally investigate the main electrodynamic characteristics of a hybrid metal-dielectric structure, including the ways of excitation and matching with external circuits, energy characteristics.Materials and methods. Hybrid metal-dielectric structure is based on inverted dielectric waveguide, which contains metallized base, dielectric rod made of polystyrene and additional dielectric plate made of glass ceramics. Auxiliary radiating elements in the form of rods of finite length with metallized face are located at certain period on the additional dielectric plate. The near-field structure measurements are carried out through the moving probe method. The isoline method has been used for field structure visualization.Results. The construction of a hybrid radiating structure based on inverted dielectric waveguide with periodically located additional rectangular dielectric rods. The radiation patterns have been measured in H-plane in two modes: short-circuit mode and travelling wave mode. Based on near-field structure measurements, the behavior of the electromagnetic wave propagating in the waveguiding rod and the degree of excitation of the metallized parts of additional structure elements are obtained. The degree of excitation of a surface wave and the possibility of its radiation are obtained. Based on this data, shielding elements insertion possibility and electromagnetic compatibility problem solution can be estimated. Conclusions: The research has revealed possible effective radiation in travelling wave mode with acceptable direct loss, provided by proposed hybrid metal-dielectric structure. Moreover, the structure can provide an acceptable level of matching with external circuits. The possibility of radiated fields with specified characteristics formation in the short circuit and traveling wave modes is demonstrated.
A Design of Terahertz Parallel Plate Dielectric Waveguide with Signal Line inserted for Ballistic Deflection Transistor Travelling Wave Amplifier