XI Международная студенческая научная конференция Студенческий научный форум - 2019

The article is devoted to the development of a dual-band dielectric resonator antenna with circular polarization for a positioning system. A computer model of the device has been developed, its parametric synthesis has been carried out. The article presents the optimal parameters of the antenna providing the specified technical characteristics.

Key words: antenna, positioning systems, dielectric resonator, microstrip antenna, loss tangent.

The interest to the millimeter wavelength range is well known. This is the possibility of miniaturization of the basic elements of radio systems, the implementation of narrow radiation patterns with antennas of small size, the presence of extensive free spectrum and acceptable attenuation of signal through a dusty atmosphere or fog.

The obtained characteristics of various geometries [1] of dielectric resonator antennas (DRA) have shown that their bandwidth and radiation efficiency can be even greater than those of many microstrip antennas, especially in very high frequency range; here dielectric materials have very small values of the loss tangent.

The main advantages of DRA are:

- high radiation efficiency due to the absence of losses in conductors or excitation of surface waves [2];

- compatible with various existing technologies for the production of antennas;

- the possibility of excitation of various wave modes in the volume of the antenna - a variety of requirements for the shape of the radiation pattern;

The purpose was to simulate a dielectric resonator antenna which operated in two frequency sub - bands: 1.2 - 1.3 GHz and 1.5-1.62 GHz (for use in GPS / GLONASS satellite positioning systems).

The final design of the antenna is a cylinder formed by two fragments of the same diameter, but of different thickness, with different permittivity. Based on the condition of circular polarization required for operation with satellite systems, despite the possibility of a serious decrease in the cross-polarization signal in rectangular DRA, as described in [3], an axisymmetric design has been chosen. Round plates of planar radiators are coaxially located at the ends of the upper cylinder.

T he resonator is located on a round printed circuit board of a two-loop quadrature bridge with equal power division.
The bridge has a circular configuration and is coaxial to cylindrical dielectric. One of the outputs of the bridge is used as aFigure 1. The DRA used model

high-frequency input, the output decoupled from it is loaded onto a matched load. Spatial excitatory elements are spaced by 90 degrees with the aim of excitation in antennas of the waves with circular polarization. The input impedance of the antenna device is 50 Ohms.

Table 1. Simulation result

The developed antenna has a small size (PCB diameter – 12.2 cm, and the height of the entire device does not exceed 4 cm), a simple design (sensitivity to tolerances on the size of the DRA is smaller than for microstrip antennas, especially in the extremely high frequency range) and fully meets the requirements that allow you to use it successfully in satellite positioning systems.

Literature:

1. Ilchenko, M. E. Dielectric resonators/ M. E. Ilchenko-M.: Radio and Communication, 1989

2. Tam, T. K. compact Dielectric Resonator, Antennas for wireless Communications. / T. K. Tam. - A Thesis of the Requirements for the Degree of Master of Philosophy in Electrical and Electronic Engineering. The Hong Kong University of Science and Technology. - 1998 –

3. Slusar, V. I. Dielectric resonator antennas. Small size, big possibilities / V. I. Sliusar // ELECTRONICA: NTB. - 2007. - №2