scholarly journals Artificially anisotropic cylinder to convert omnidirectional linear polarization into circular polarization

2017 ◽  
Author(s):  
E. Kaivanto ◽  
E. Salonen ◽  
M. Berg
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Anisotropic Cylinder

scholarly journals Broadband Linear Polarization in Ap Stars

1993 ◽  
Vol 138 ◽  
pp. 305-309
Author(s):  
Marco Landolfi ◽  
Egidio Landi Degl’Innocenti ◽  
Maurizio Landi Degl’Innocenti ◽  
Jean-Louis Leroy ◽  
Stefano Bagnulo
Keyword(s):  
Magnetic Field ◽  
Circular Polarization ◽  
Linear Polarization ◽  
Rotation Axis ◽  
Spectral Lines ◽  
Line Of Sight ◽  
Long Time ◽  
Rotating Star ◽  
Ap Stars ◽  
The Magnetic Field

AbstractBroadband linear polarization in the spectra of Ap stars is believed to be due to differential saturation between σ and π Zeeman components in spectral lines. This mechanism has been known for a long time to be the main agent of a similar phenomenon observed in sunspots. Since this phenomenon has been carefully calibrated in the solar case, it can be confidently used to deduce the magnetic field of Ap stars.Given the magnetic configuration of a rotating star, it is possible to deduce the broadband polarization at any phase. Calculations performed for the oblique dipole model show that the resulting polarization diagrams are very sensitive to the values of i (the angle between the rotation axis and the line of sight) and β (the angle between the rotation and magnetic axes). The dependence on i and β is such that the four-fold ambiguity typical of the circular polarization observations ((i,β), (β,i), (π-i,π-β), (π-β,π-i)) can be removed.

scholarly journals Simultaneous Five Color (UBVRI) Polarimetry of VV Puppis

1987 ◽  
Vol 93 ◽  
pp. 203-203
Author(s):  
V. Piirola ◽  
A. Reiz ◽  
G.V. Coyne
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Wavelength Dependence ◽  
Position Angle ◽  
Orbital Inclination ◽  
V Band ◽  
Highly Active ◽  
Phase Interval ◽  
In The Beginning ◽  
Bright Phase

AbstractObservations of linear and circular polarization in five colour bands during a highly active state of VV Puppis in January 86 are reported. A strong linear polarization pulse with the maximum in the blue, PB ≈ 22%, is observed at the end of the bright phase when the active pole is at the limb and a weaker secondary pulse, PB ≈ 7%, is seen in the beginning of the bright phase, when the active pole reappears. Strong positive circular polarization is also observed in the blue and the ultraviolet, РU ≈ PB ≈ 18%, PV ≈ 10% during the bright phase. The circular polarization reverses the sign in the B and V bands during the faint phase and a negative polarization hump is seen when the active pole crosses the limb. The circular polarization in the V band reaches the value PV ≈ −10% at the hump, after which it remains near PV ≈ −5% during the faint phase. This is probably due to radiation coming from the second, less active pole and accretion thus takes place onto both poles. The wavelength dependences of the positive and negative parts of the circular polarization curve are different and no polarization reversal is seen in the U band. The position angle of the linear polarization is well determined during a large portion of the cycle, especially in the V band, thanks to the activity from both poles. A best fit to the position angle curve, taking into account also the duration of the positive circular polarization phase interval ΔΦ = 0.40 (in the V band), yields the values of orbital inclination i = 78° ± 2° and the colatitude of the active magnetic pole ß = 146° ± 2°. The relatively good fit to the position angle data indicates that the simple dipole model is nearly correct in the case of VV Puppis. Some wavelength dependence is, however, seen in the position angle curves, especially in the I band where the slope Δθ/ΔΦ at the main pulse is considerably smaller than in the other bands. The shape of the position angle curves changes also in the blue and the ultraviolet around the middle of the bright phase. This is probably due to optical thickness effects as the side of the accretion column which is toward the observer changes near this phase.

Polarization Reconfigurable Dual-Band Rectangular Slot Antenna

Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 339-351
Author(s):  
Rohit Kumar Saini
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Dual Band ◽  
Slot Antenna ◽  
Pin Diodes ◽  
Rectangular Slot ◽  
Left Hand ◽  
Right Hand ◽  
Lower Band ◽  
The Senses

Abstract A novel dual-band rectangular slot antenna is presented for dual-sense reconfigurable polarization. A W-shaped microstrip feedline and two rectangular parasitic patches are used to obtain dual-band circular polarization. Further, the feedline is modified so that the senses of polarization at the two bands are opposite. By introducing PIN-diodes in the feed lines, polarization can be switched among left-hand circular polarization (LHCP), right-hand circular polarization (RHCP), and linear polarization (LP). A prototype dual-band dual-sense antenna with f01 = 1.9 GHz and f02 = 3.45 GHz is fabricated in a 1.6 mm thick FR4 substrate. The measured circular polarized bandwidths are more than 7.6 % for the lower band and 5 % for the upper band.

Design of multiband circularly/linearly polarized antenna for multiple wireless (WWAN/Bluetooth/WiMAX/WLAN/Downlink Satellite System)

2019 ◽  
Vol 11 (9) ◽  
pp. 967-974 ◽  
Author(s):  
Manish Sharma
Keyword(s):  
Wireless Communications ◽  
Circular Polarization ◽  
Radiation Pattern ◽  
Linear Polarization ◽  
Ground Plane ◽  
Wireless Systems ◽  
Satellite System ◽  
Multiband Antenna ◽  
Linearly Polarized ◽  
Downlink System

AbstractIn this article, a multiband antenna for various wireless communications is proposed for WWAN, Bluetooth, WiMAX, WLAN, and Downlink satellite system. The antenna consists of a radiating patch and a rectangular ground plane with four L-shaped stubs which are embedded as side arms to obtain a resonating band for WWAN (1.9GHz), Bluetooth (2.4 GHz), WiMAX (2.5, 3.5, and 5.5 GHz), and WLAN (5.5 GHz) wireless systems and a C-shaped stub is etched on the radiating patch to obtain a higher WLAN band (2.4, 5.2, and 5.8 GHz) and a satellite downlink system (7.5 GHz). The proposed antenna exhibits circular polarization at WWAN band and linear polarization for remaining applications. Also, the proposed antenna exhibits an omnidirectional radiation pattern.

scholarly journals Circular polarization in T Tauri stars

1987 ◽  
Vol 122 ◽  
pp. 131-132
Author(s):  
P. Bastien ◽  
R. Nadeau
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
T Tauri Stars ◽  
T Tauri

We report the detection of circular polarization in three T Tauri stars with known intrinsic linear polarization. A circumstellar origin is required.

scholarly journals Interstellar Circular Polarization and the Composition of Interstellar Dust

1973 ◽  
Vol 52 ◽  
pp. 161-167 ◽  
Author(s):  
P. G. Martin
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Interstellar Dust ◽  
Principal Axis ◽  
Complex Refractive Index ◽  
Polarized Light ◽  
Position Angle ◽  
Optical Observations ◽  
Small Component ◽  
Linearly Polarized

This paper shows that optical observations of circular polarization produced by aligned interstellar grains could yield valuable information about the grain material. The interstellar medium is known to be linearly dichroic from observations of interstellar linear polarization; many different grain models using a large variety of compositions can be found to reproduce these observations. Since the same aligned grains make the medium linearly birefringent, a small component of circular polarization can result from incident linearly polarized light if the position angle of the linear polarization does not coincide with either principal axis of the medium. Here calculations are presented to demonstrate that the wavelength of the circular polarization is sensitive to the imaginary part of the complex refractive index of the grain material. This provides an opportunity of investigating whether the grains are characteristically dielectric or metallic. Some possible observations are suggested.

scholarly journals Pulsar NP 0532: Recent Results on Strong Pulses Obtained at Arecibo

1971 ◽  
Vol 46 ◽  
pp. 103-109
Author(s):  
Carl Heiles ◽  
John M. Rankin
Keyword(s):  
Circular Polarization ◽  
Frequency Spectrum ◽  
Linear Polarization ◽  
The Other ◽  
Average Intensity ◽  
Detailed Structure ◽  
Continuous Frequency

New observations have been made of strong pulses from NP 0532. Linear polarization is typically 25 per cent and circular polarization is less than 10 per cent but definitely not zero. A comparison of pulse shapes at 429.9 and 430.1 MHz showed significant differences in detailed structure and polarization. In another study strong pulses at 318 and 111 MHz did not occur together although a strong pulse at one frequency was accompanied by an above average intensity at the other frequency. Similar behaviour was found at 111 and 74 MHz. We conclude that strong pulses do not have a smooth continuous frequency spectrum.

scholarly journals Polarization in Pulsar Radio Emission

1992 ◽  
Vol 128 ◽  
pp. 384-386
Author(s):  
D. M. GOULD
Keyword(s):  
Radio Emission ◽  
Circular Polarization ◽  
Linear Polarization ◽  
Large Data ◽  
Position Angle ◽  
Published Data ◽  
Data Set ◽  
Pulsar Radio ◽  
Polarization Profiles ◽  
Pulsar Radio Emission

Polarimetric observations of over 300 pulsars have been carried out between 21 December 1988 and 22 January 1990 at 606, 610, 925, and 1408 MHz using the Lovell Telescope at Jodrell Bank. Many of these pulsars have no previously published polarization profiles and will be published shortly (Gould and Lyne 1990). This large data set along with previously published data from various sources, has been used to test the correlation found by Radhakrishnan and Rankin (1990) between sense reversing circular polarization signatures and the accompanying sense of rotation of the linear polarization position angle.

scholarly journals Dual- Band Antenna for Wi-Fi and 5G Applications

2019 ◽  
Vol 9 (1S5) ◽  
pp. 130-131
Keyword(s):  
Circular Polarization ◽  
Linear Polarization ◽  
Patch Antenna ◽  
Return Loss ◽  
Axial Ratio ◽  
Band Width ◽  
Dual Band ◽  
Circular Patch ◽  
Dual Band Antenna ◽  
Circular Patch Antenna

In this communication, a circular patch antenna is reported for dual- band operation based on VIAs. Initially the patch is resonating at single band with Linear Polarization (LP), and the Circular Polarization (CP) is obtained by inserting semi circular cuts at the edges of circular patch. The second band is achieved by loading the vertical metallic VIAs along the circumference of the patch antenna. The reported antenna is working at 2.4 GHz (Wi-Fi) and 3.5 GHz (5G) bands with Return Loss Band Width (RLBW) of 4.83% and 10.37% respectively. The Axial Ratio (AR) bandwidth at 5G band is 2.38% (3.31- 3.39 GHz)

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