ANALYSIS OF CHARACTERISTICS OF A PLANAR BROADBAND DOUBLE RING ANTENNA

Abstract

The topology is presented and the electrodynamic characteristics of the linear polarization antenna in the form of two planar partially intersecting circular disks are considered. Each of these discs has a hole in the centre, and in the area of their intersection there is a narrow longitudinal rectangular slot whose axis is oriented in the direction of the centres of the holes. Results of numerical simulation of the characteristics of such an antenna are presented, discussed and compared. Broadband properties of this antenna are explained by the presence in its design of two broad partially crossed planar rings and a relatively short narrow slot, which is excited in the region of their intersection. This feature provides a sufficiently wide band of operating frequencies, both in directivity characteristics and in input impedance. In this case, the antenna has an input resistance about 50 ... 60 Ohm, which can be adjusted by changing the width of the slot and rings. For comparison, similar characteristics of small-size low-directional antennas, such as vertical monopole, slot half-wave antennas and a zigzag antenna (the Kharchenko antenna or the "Z-antenna") are also considered in this paper. It is shown that the antenna under consideration possesses, in comparison with them, improved frequency properties, both in matching at the input and in the directivity. Along with broadband, the advantages of such an antenna are: an increased value of the directivity as compared to the monopole and dipole wire structures, and also a simple manufacturing technology that gives a certain benefit in mass production.