Conformal cylindrical microstrip loop radiator input impedance calculation

Abstract

Problem statement. Antennas that fully or partially repeat the shape of the object on which they are placed are called conformal. The main areas of application of conformal antennas are aviation, rocketry, and vehicles. Despite the presence of a large number of publications devoted to conformal antennas in our country and abroad, issues related to the formation of the radiation characteristics of conformal microstrip antennas, as well as the influence of the overall dimensions and geometry of the emitter on the radiation characteristics, have still not been sufficiently studied. Goal. The purpose of this work was to obtain an approximate formula for calculating the input impedance of a conformal cylindrical microstrip loop radiator. Results. In this article, an integral equation is obtained for the unknown current density distribution function on the surface of a conformal cylindrical microstrip loop radiator; as a result of its solution, an approximate formula for this function is obtained. An approximate formula for calculating the input impedance is obtained. The dependences of the input impedance of a conformal cylindrical microstrip loop radiator on its length normalized to the wavelength are calculated. Practical significance. The proposed method for calculating the input impedance of a conformal cylindrical microstrip loop radiator makes it possible to effectively calculate and study the dependence of the input impedance on the geometric dimensions of the emitter, as well as the dimensions and electrodynamic parameters of the substrate. This technique can be generalized to emitters located on substrates made of other materials, for example, chiral metamaterials.