Broadband simultaneously RHCP-LHCP radiating microstrip fed rectangular slot antenna for polarization diversity applications

Abstract

In this article, for the first time, an antenna that can radiate LHCP and RHCP waves simultaneously is presented. The antenna enables simultaneous transmission of both right-handed (RH) and left-handed (LH) circular polarized (CP) waves separately over an elevation range from −45 to −5 and 5 to 45 from the zenith. The simultaneous radiation of dual sense CP in the different spatial directions enables the antenna to act as polarization diversity transmitter. The mechanism of virtual sequential rotation of magnetic currents inside the different parts of the slot, excited with uniform phase fields results in dual CP generation. The uniform phase orthogonal fields are generated in the different parts of the slot essentially by exciting the full wavelength rectangular slot loaded with grounded stubs, symmetrically, with a shorted microstrip line. The final design of the slot antenna arrived with a rigorous parametric study on different dimensional parameters of slot and grounded stub. The measured impedance bandwidth of 22.5% centered around 7 GHz and axial ratio bandwidth of 19% is achieved. An overlapping bandwidth of 17% is achieved where both matching and AR are very good. The measured isolation between the RHCP and LHCP in the above-mentioned elevation ranges is maintained above 10 dB. The simulated and experimental results are matching very well. K E Y W O R D Saxial ratio, left-handed CP, magnetic currents, Mobile satellite communications, polarization diversity, rectangular slot, right-handed CP, simultaneous dual CP

On the design of ideal pattern diversity antennas with low mutual coupling using the golden angle concept

“…[12][13][14][15] Antennas that can radiate different polarizations in the different radiation beams were also reported. 16,17 But, none of these designs [4][5][6][7][8][9][10][11][12][13] provided a fundamentally robust scheme for achieving ideal pattern diversity with large number of elements. It is believed that a proper antenna arrangement is necessary to close this technological gap.…”

“…One is pattern switchable antenna elements with port selection, 8–11 another is pattern diversity with the help of placement of antennas 12–15 . Antennas that can radiate different polarizations in the different radiation beams were also reported 16,17 …”