Wide bandwidth left-handed circularly polarized printed antenna with crescent slot

2017 ◽  
Author(s):  
Farohaji Kurniawan ◽  
Josaphat Tetuko Sri Sumantyo ◽  
Gunawan Setyo Prabowo ◽  
Achmad Munir
Keyword(s):  
Printed Antenna ◽  
Wide Bandwidth ◽  
Circularly Polarized ◽  
Left Handed

Modulation instability in nonlinear chiral fiber

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Demissie Jobir Gelmecha ◽  
Ram Sewak Singh
Keyword(s):  
Theoretical Model ◽  
Numerical Simulations ◽  
Pulse Propagation ◽  
Modulation Instability ◽  
Constitutive Relations ◽  
Gain Spectrum ◽  
Circularly Polarized ◽  
Left Handed ◽  
Simulation Results ◽  
The Difference

AbstractIn this paper, the rigorous derivations of generalized coupled chiral nonlinear Schrödinger equations (CCNLSEs) and their modulation instability analysis have been explored theoretically and computationally. With the consideration of Maxwell’s equations and Post’s constitutive relations, a generalized CCNLSE has been derived, which describes the evolution of left-handed circularly polarized (LCP) and right-handed circularly polarized (RCP) components propagating through single-core nonlinear chiral fiber. The analysis of modulation instability in nonlinear chiral fiber has been investigated starting from CCNLSEs. Based on a theoretical model and numerical simulations, the difference on the modulation instability gain spectrum in LCP and RCP components through chiral fiber has been analyzed by considering loss and chirality into account. The obtained simulation results have shown that the loss distorts the sidebands of the modulation instability gain spectrum, while chirality modulates the gain for LCP and RCP components in a different manner. This suggests that adjusting chirality strength may control the loss, and nonlinearity simultaneously provides stable modulated pulse propagation.

S-Band Full-Metal Circularly-Polarized Cavity-Backed Slot Antenna with Wide Bandwidth and Wide Beamwidth

2021 ◽  
pp. 1-1
Author(s):  
Rui-Sen Chen ◽  
Lei Zhu ◽  
Sai-Wai Wong ◽  
Jing-Yu Lin ◽  
Yin Li ◽  
...  
Keyword(s):  
Slot Antenna ◽  
Wide Bandwidth ◽  
Circularly Polarized

scholarly journals A high-efficiency and ultrathin transmission-type circular polarization converter based on surface structure

2021 ◽  
Vol 8 ◽  
pp. 4
Author(s):  
Peng Xu ◽  
Wei Xiang Jiang ◽  
Xiao Cai ◽  
Yue Gou ◽  
Tie Jun Cui
Keyword(s):  
High Efficiency ◽  
Transmission Mode ◽  
Polarization Converter ◽  
Periodic Surface ◽  
Circularly Polarized ◽  
Left Handed ◽  
Via Holes ◽  
Working Frequency ◽  
The Right ◽  
Good Agreement

In this paper, we propose, design and fabricate a kind of ultrathin and high-efficiency circularly polarization converter based on artificially engineered surfaces in the transmission mode. The converter is composed of double-layer periodic surface structures with cross slots. The top and bottom layers are printed on both sides of the F4B substrate and connected by metallic via holes. The proposed converter can transform the right-handed circularly polarized incident electromagnetic (EM) wave to a left-handed circularly-polarized one with near-unity efficiency in the transmission mode, or vice versa. We explain the conversion mechanism based on numerical simulations and equivalent circuit (EC) theory. The measured result has a good agreement with the simulated one in the working frequency band. Such ultrathin polarization converters can be used in wireless microwave communication, remote sensing, and EM imaging where circularly polarization diversity is needed.

scholarly journals Dual-Circularly Polarized 60 GHz Beam-Steerable Antenna Array with 8 × 8 Butler Matrix

2020 ◽  
Vol 10 (7) ◽  
pp. 2413 ◽  
Author(s):  
Yuntae Park ◽  
Jihoon Bang ◽  
Jaehoon Choi
Keyword(s):  
Circular Polarization ◽  
Antenna Array ◽  
Mutual Coupling ◽  
Beam Steering ◽  
60 Ghz ◽  
Circularly Polarized ◽  
Butler Matrix ◽  
Left Handed ◽  
Steerable Antenna ◽  
The Right

A beam-steerable dual-circularly polarized 60 GHz antenna array is proposed. A 1 × 4 dual-fed stacked patch antenna array is integrated with an 8 × 8 Butler matrix. By utilizing the 8 × 8 Butler matrix, the proposed antenna array generates dual-circular polarization with beam-steering capability. The proposed antenna array system demonstrates good reflection coefficients in the frequency band ranging from 55.3 GHz to 64.9 GHz and has a mutual coupling of less than −10 dB over the frequency range of 57.5 GHz–63.2 GHz. At 60 GHz, the maximum gains and beam-steering angles for input ports 2, 4, 5, and 7 are 9.39 dBi at −38°, 10.67 dBi at −11°, 10.63 dBi at +11°, and 9.38 dBi at +39°, respectively. It is also demonstrated that the dual-polarization is well formed by switching the excitation ports. The right-handed circular polarization (RHCP) is formed when four ports from port 1 to port 4 are excited and left-handed circular polarization (LHCP) is formed when four ports from port 5 to port 8 are excited. The proposed antenna array system could be a good candidate for millimeter-wave 5G applications that require wide beam coverage and polarization diversity.

scholarly journals Balanced gain for a square metaloop antenna

2019 ◽  
Vol 6 ◽  
pp. 3
Author(s):  
Hisamatsu Nakano ◽  
Ittoku Yoshino ◽  
Tomoki Abe ◽  
Junji Yamauchi
Keyword(s):  
Frequency Response ◽  
Radiation Pattern ◽  
Free Space ◽  
Loop Antenna ◽  
Circularly Polarized ◽  
Left Handed ◽  
The Difference

A square loop antenna implemented using a metamaterial line, referred to as a metaloop, is discussed. The metaloop radiates a counter circularly polarized (CP) broadside beam when the loop circumference equals one guided wavelength. The frequency response of the gain shows two different maximum values: gain G Lmax for a left-handed CP wave at frequency fGLmax and gain GRmax for a right-handed CP wave at frequency fGRmax, where GLmax is smaller than GRmax. In order to increase GLmax, while not affecting the original GRmax as much as possible (i.e. balance the gain), a parasitic natural conducting loop (paraloop), whose circumference is one free-space wavelength at fGLmax, is placed at height Hpara above the metaloop. It is found that the difference in the gains can be reduced by choosing an appropriate Hpara. The radiation pattern at fGLmax is narrowed by the paraloop, while the VSWR is not remarkably affected.

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