Electrodynamic Characteristics of Fields of Two Orthogonal Pairs of In-Phase Excited Impedance Dipoles Located Parallel to Square Screen.

Autor: Yeliseyeva, N. P., Berdnik, S. L., Gorobets, M. M.
Předmět:
Zdroj: Radioelectronics & Communications Systems; Oct2023, Vol. 66 Issue 10, p515-530, 16p
Abstrakt: Three-dimensional vector problems of diffraction of fields of two parallel impedance dipoles and two orthogonal pairs of such dipoles located parallel to a perfectly conducting rectangular screen at its edges have been solved by the method of uniform geometric diffraction theory using uniform asymptotic expressions for diffracted fields excited by a dipole at the edge of a perfectly conducting half-plane. Approximate asymptotic expressions for the current distribution in a thin horizontal impedance dipole located above a perfectly conducting infinite plane are used to determine the current distribution in impedance dipoles. Fast computational programs have been developed to determine the surface impedances of pairs of dipoles above the screen, provided that the resonant or circularly polarized radiation is generated in the direction normal to the screen. To synthesize the circular polarization of the field in the direction of the normal to the screen and simultaneously to provide the axial symmetry of the radiation patterns (RP), it was proposed to use two pairs of in-phase excited impedance dipoles with orthogonal orientation and different corresponding surface impedances. It has been proved that the RP, according to the field power of the resonant and circularly polarized four-vibrator radiators located at the distance of a quarter of antenna operating wavelength above a square screen with a side of 1.2 wavelengths and a distance between parallel dipoles of 0.51 of wavelength have axial symmetry in the sector of observation angles ±45° to relative levels of –12 dB. The main lobes of the RP in terms of orthogonal field components in the main observation planes converge to a relative level of –20 dB in the sector of angles ±70° from the normal to the screen. At the same time, in the case of a circularly polarized radiator, the value of the ellipticity coefficient is not less than 0.9. The calculated RP was verified using the Feko program. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: