Теория круглой микрополосковой антенны

Abstract

The paper discusses the methodology of calculation of circular microstrip antenna. The antenna itself has been presented as a cylindrical resonator electrically small height. The mathematical description of the electromagnetic field inside the cavity volume and fields acting on the side wall of the cavity is presented. Input impedance of the antenna and the resonator formed on the sidewall of the cavity and the gain coefficient of the directional antenna are calculated. An evaluation of mathematical modeling of the simulated values is obtained match within 5%. Mathematical modeling of the directivity factor and the quality factor is performed. To solve the problem of the radial waveguide excitation we used the expression for the longitudinal component of the electric field as a sum of incident and reflected waves with unknown coefficients of reflection. The analytical expressions were derived through the Bessel and Hankel function for them. To determine the field in the outer region of the gap instead of a side wall of the cavity located above the screen the annular slit unilateral radiation slotted in an infinite plane screen is mapd. It is acceptable because of the low height of the cavity. The input impedance of the antenna excited at the edge of the disc was induced electromotive force method. Restrict expression using dielectrics with high permittivity (fiberglass, ceramics, polycor etc.) is presented in this paper, but it provides an opportunity to obtain simple settlement relations. The obtained relations allow to analyze explicitly the basic laws. Due to the miniaturization of microelectronics problem the calculating microstrip antennas is very important. Thus, the approximate formulas with a very simple form provide a good estimate of the basic electrical characteristics of the circular strip (disk) antennas.