Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an ...

We have shown that a reverse energy flow (negative projection of the Poynting vector onto optical axis) at sharp focus an vortex with topological charge 2 and left-hand circular polarization arises because axial spin has negative axis is greater in magnitude than positive orbital (canonical flow). Also, using Richards-Wolf formulas, it when focusing left-handed circularly polarized light, regio...

Abstract In this letter, a low‐profile metasurface (MS) antenna with multi‐polarization and pattern reconfigurability is presented. The mainly consists of two parts, including loop fed by balun, MS excited the coupled aperture. When switching PIN diode rotating MS, reconfigurable ability obtained. While excited, horizontally linear polarized (HLP) wave omnidirectional are Besides, when operated...

There are two popular approaches to the design of a polarimetric radiometer: using either coherent or incoherent detection. Coherent detection implies that a direct cross-correlation is performed of the vertical and horizontal components of the incident electrical field. Incoherent detection derives the third and fourth Stokes parameters indirectly, by differencing the brightness temperatures d...

Measurement of the third and fourth Stokes parameters of microwave thermal emission can be degraded by nonideal radiometer characteristics. Of particular importance is the level of polarization purity and the knowledge of polarization impurity on the part of the instrument. An explicit relationship is developed between the true Stokes parameters and the measurements, as functions of nonideal po...

It is well known that directional antennas and circular polarization (CP) antennas are effective in reducing degradations of receiving power caused by multipath propagation effects [1]. Therefore, simultaneous controlling these two features—directivity and polarization—is expected to considerably reduce such adverse effects. Some papers have reported CP antennas with beam steering means [2], [3...

The circular dichroism in the total and partial ion yields of methyl-oxirane C3H6O was measured at the C 1s and O 1s edges. The difference of the response of the chiral molecule to circularly polarized light with opposite handedness was found to be less than 0.2% for the total ion yield and less than 0.5% for the partial ion yield. Additionally we tried to find a dipole allowed molecular orient...

Previous studies on hybrid dielectric-graphene metasurfaces have been used to implement induced transparency devices, while exhibiting high Q-factors based on trapped magnetic resonances. Typically, the transparency windows are single wavelength and less appropriate for polarization conversion structures. In this work, a quarter-wave plate based on a hybrid silicon-graphene metasurface with con...

This article presents a wideband dual-circular-polarization (dual-CP) antenna with high port isolation based on grooved-wall CP horn combined an orthomode transducer (OMT) in the W-band. A pair of grooves inner wall serves as inbuilt polarizer within antenna, which is capable generating both left-hand circular polarization (LHCP) and right-hand (RHCP) without any septum. The continuous linearly...

We present results from archival Very Large Array (VLA) data and new VLA observations to investigate the long term behavior of the circular polarization of M81*, the nuclear radio source in the nearby galaxy M81. We also used the Berkeley-Illinois-Maryland Association (BIMA) array to observe M81* at 86 and 230 GHz. M81* is unpolarized in the linear sense at a frequency as high as 86 GHz and sho...