An approach to the evaluation of mutual resistances of vibrators in the construction of a logoperiodic antenna of double polarization

В данной работе приведены результаты теоретического исследования взаимного влияния двух вибраторов, произвольно ориентированных в пространстве. Авторы на основе метода наведенных ЭДС определили касательную составляющую электрического поля, создаваемого одним из вибраторов в месте расположения второго. С использованием данного выражения авторы предложили три способа оценки взаимного сопротивления системы двух скрещенных симметричных вибраторов. Сравнив способы по точности вычислений и затрачиваемому машинному времени, авторы выделили один из предложенных способов для проведения модельных исследований. Особенностью предложенного способа является возможность обобщения расчетного выражения не только для случая скрещенных вибраторов, но и для случаев вибраторов, расположенных в параллельных плоскостях и перпендикулярных одной и той же прямой. Поскольку указанные случаи охватывают все возможные варианты взаимной ориентации вибраторов в конструкции логопериодической антенны двойной поляризации, то предложенный подход может быть использован при проведении модельных исследований направленных свойств логопериодической антенны и оценки уровня кросс-поляризации. The results of two arbitrarily oriented in space vibrators mutual influence theoretical study are presents in this paper. Based on the method of induced EMF, the authors determined the tangential component of the electric field created by one of the vibrators at the location of the second one. Using this expression, the authors proposed three ways to evaluate the mutual resistance of a system of two crossed symmetrical vibrators. Comparing the methods by the accuracy of calculations and the machine time spent, the authors identified one of the proposed methods for conducting model studies. A feature of the proposed method is the possibility of generalizing the calculated expression not only for the case of crossed vibrators, but also for the cases of vibrators located in parallel planes and perpendicular to the same straight line. Since these cases cover all possible variants of mutual orientation of vibrators in the construction of a logoperiodic antenna of double polarization, the proposed approach can be used in conducting model studies of directional properties of a logoperiodic antenna and assessing the level of cross-polarization.

General helicity formalism for two-hadron production in e+e− annihilation within a TMD approach

We present the complete leading-order results for the azimuthal dependences and polarization observables in e+e−→ h1h2 + X processes, where the two hadrons are produced almost back-to-back, within a transverse momentum dependent (TMD) factorization scheme. We consider spinless (or unpolarized) and spin-1/2 hadron production and give the full set of the corresponding quark and gluon TMD fragmentation functions (TMD-FFs). By adopting the helicity formalism, which allows for a more direct probabilistic interpretation, single- and double-polarization cases are discussed in detail. Simplified expressions, useful for phenomenological analyses, are obtained by assuming a factorized Gaussian-like dependence on intrinsic transverse momenta for the TMD-FFs.

An experimental millimeter wave radio over fiber link with double polarization multiplexing

A novel approach, an optical radio over fiber link with double polarization multiplexing is presented. In the two orthogonal polarizations of the optical beam the contents of information to be transmitted are different doubling the link capacity this way. For experimental verification a millimeter wave radio over fiber link with double polarization multiplexing has been developed. To ensure low cross polarization an incoherent approach is used. A high quality signal transmission is achieved by a proper procedure providing high polarization extinction ratio. In the experimental investigations different bit rates and fiber lengths are used. A signal with 12 Gbit/s bit rate is transmitted over a 25 km long link with about 1.10–8 bit error rate. That result is much better than the already published data measured on experimental links.

Research efficiency use of orthogonal double polarization MIMO antennas in drone communication

The article considers possible variants of application of various MIMO schemes for the communication with the drone or unmanned aerial vehicle. The model of multipath propagation of radio waves taking into account polarization parameters of antennas is given. The main focus is on the use of MIMO technology with polarization-orthogonal channels and channels with double polarization. The evaluation of the efficiency of using full polarization reception in comparison with MIMO channels of one polarization is given. Attention is paid to the presence of cross-polarization solution between the channels.

An Experimental Millimeter Wave Radio over Fiber Link with Double Polarization Multiplexing

A novel approach, an optical radio over fiber link with double polarization multiplexing is presented. In the two orthogonal polarizations of the optical beam the contents of information to be transmitted are different doubling the link capacity this way . For experimental verification a millimeter wave radio over fiber link with double polarization multiplexing has been developed. To ensure low cross polarization an incoherent approach is used. A high quality signal transmission is achieved by a proper procedure providing high polarization extinction ratio. In the experimental investigations different bit rates and fiber lengths are used. A signal with 12 Gbit/s bit rate is transmitted over a 25 km long link with about 1.10 -8 bit error rate. That result is much better than the already published data measured on experimental links.

Measurement of the helicity asymmetry E for the reaction $$ \gamma p\rightarrow \pi ^0 p$$

A measurement of the double-polarization observable E for the reaction $$\gamma p\rightarrow \pi ^0 p$$ γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$$_4$$ 4 H$$_9$$ 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $$E_\gamma =600$$ E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.