Results 21 to 30 of about 286,161 (299)
Sensors, 2021 A compact ultra-wideband dual-polarized Vivaldi antenna is proposed for full polarimetric ground-penetrating radar (GPR) applications. A shared-aperture configuration comprising four Vivaldi elements for orthogonal polarizations is designed to reduce the
Hai-Han Sun +5 more
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IEEE Access, 2017 A fast dual polarization hopping (FDPH) system is designed to enhance the physical layer secure transmission in fixed down-link satellite communications. In order to prevent the eavesdropper from detecting transmitted signals, a pair of dual polarization
Xiaokai Zhang +2 more
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Polar Duals of Convex Bodies [PDF]
Proceedings of the American Mathematical Society, 1991 The author establishes several inequalities which relate mixed volumes of a convex body \(K\) in \(\mathbb{R}^ n\) and its polar, \(K^*\). A typical example is \[ V(K^*,K,\dots,K)^ n\geq\omega^ 2_ nV(K)^{n-2}, \] where \(\omega_ n\) is the volume of the unit ball and \(V(K):=V(K,\dots,K)\) stands for the volume of \(K\).
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On "New Massive" 4D Gravity [PDF]
, 2012 We construct a four-dimensional (4D) gauge theory that propagates, unitarily, the five polarization modes of a massive spin-2 particle. These modes are described by a "dual" graviton gauge potential and the Lagrangian is 4th-order in derivatives.
A Vainshtein +24 more
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Discrete Mathematics, 2006 AbstractThe smallest number of points of an incidence structure which is self-dual but not self-polar is 7. For non-binary structures (where a “point” may occur more than once in a “block”) the number is 6.
Brouwer, A.E. +3 more
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A Multioctave 8 GHz
IEEE Journal of Microwaves, 2023 Accurate measurement of angular positions on the sky requires a well-defined system of reference, something that in practice is realized by the International Celestial Reference Frame (ICRF) with observations of distant (typical redshift $\sim$1) Active ...
Jacob W. Kooi +17 more
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Dual Circularly Polarized Reflectarray With Independent Control of Polarizations [PDF]
IEEE Transactions on Antennas and Propagation, 2015 A reflectarray with independent dual-circular polarizations is proposed for the first time. The reflector panel operates in X-band and contains 97 unit-cells. It is made with a lego-type configuration allowing change manually the phase aperture distribution and demonstrating experimentally the independence of both polarizations in the same frequency ...
Mener, Simon +4 more
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Fully Planar Dual-Polarized Broadband Antenna for 3G, 4G and Sub 6-GHz 5G Base Stations
IEEE Access, 2020 A fully planar dual polarized radiating element with internal embedded coupled dipoles is presented in this paper. The inclusion of these elements allows achieving three different goals: firstly, an extension of the bandwidth towards lower frequencies ...
Sergio Martin-Anton +1 more
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Vacuum polarisation induced coupling between Maxwell and Kalb-Ramond Fields [PDF]
, 2001 We present here a manifestly gauge invariant calculation of vacuum polarization to fermions in the presence of a constant Maxwell and a constant Kalb-Ramond field in four dimensions.
A. Smailagic +17 more
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Dual-polarized UWB antenna array
2009 IEEE International Conference on Ultra-Wideband, 2009 The paper describes a dual-polarized antenna array for Impulse Radio Ultra Wideband (IR-UWB) applications. Firstly a brief description of the single radiator is given. Next the prototype is presented and measured data is compared with the simulated one. The linear array consisting of four components achieves a very narrow mean 3 dB beam width, which is
Adamiuk, G. +3 more
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