Huellas de la Disputa en la cultura europea

Sin resume

Sobre un topónimo no identificado Š.L.N.Š

Sin resume

Homer Presence: Iliad, II, 204 in the Arabic-Islamic Culture

Se pone de manifiesto en este trabajo la presencia en la cultura árabe-islámica del verso II, 204 de la Ilíada en el que se defiende la jefatura única, verso que a través de Aristóteles ha tenido gran repercusión en Occidente y que, en menor medida, también ha sido tenido en cuenta en el mundo árabe, destacando el comentario de Miskawayh, comentario que es traducido aquí.The presence in the Arabic-Islamic culture of Iliad, II, 204 is investigated in this work. This verse argues that only one persone should govern and, thanks to Aristotle, it has had a great repercussion in the West and, in minor measure, it has been also taken in account in the Arabic world, highlighting Miskawayh comment, comment that is translated here

On coercion and freedom in classical islamic thought

En este trabajo, después de contrastar la opinión de Kant y Aristóteles sobre la responsabilidad y la libertad ante la coacción, y tras unas sucintas consideraciones sobre el tema de la libertad en el pensamiento islámico, se pasa revista a lo que sobre la coacción han dicho los pensadores más representativos del área islámica clásica. Estos pensadores son, ante todo, los mutakallimíes, los “teólogos” del islam, distinguiéndose entre ellos un grupo, los muʿtazilíes, que son los que han dado mayor entrada a la razón en sus especulaciones, y entre estos destacan los análisis de ‘Abd al-Jabbâr (m. 1025) que es el autor que más se ha ocupado de este asunto. Finalmente se contrasta la opinión de este autor con las de al-Bâqillânî (m. 1013) y Algazel (m. 1111), cuya solución es muy próxima a la de Kant.In this study, after contrasting the views of Kant and Aristotle on responsibility and freedom with respect to coercion, and after brief considerations on the issue of freedom in Islamic thought, we review what the most representative thinkers of the classical Islamic area have said about coer-cion. These thinkers are, above all, the mutakallimimūn, the “theologians” of Islam, particularly the Mu'tazilites, the group which gave the greatest place for reason in their discussions, and standing out among them ‘Abd al-Jabbâr (d. 1025), whose analyses dealt most with this matter. Finally, the opinion of ‘Abd al-Jabbâr is contrasted with those of al-Bâqillânî (d. 1013) and Algazel (d. 1111), whose solution is very close to that of Kant

Two-dimensional Quasi-bessel beam synthesis and frequency-scanning leaky-wave launchers

In this paper, a technique to synthesize a 2D frequency-scanned high order Bessel beam in a parallel plates waveguide (PPW) scenario is presented. This technique is based on a one dimensional beam launcher, rather than the more typical axicons or the more recent metasurfaces and antenna arrays for 3D Bessel beam synthesis. With this launcher, it is possible to generate a 2D Bessel beams whose direction can be controlled by changing the frequency of the feeding signal in the Ku band from 14.5 GHz to 15 GHz. It is demonstrated how this can be done by combination of two leaky waves (LW), which can be created by the same 1D structure, scanning at different angles and launched to the PPW region. The beams are generated in a triangular area, with one of its sides being the launcher itself and the other sides are defined by the direction of radiation of each of the forming leaky wave

Handmade Microstrip Leaky-Wave Antenna in UHF band for Educational Purposes.

The design, manufacture and testing of a micro strip leaky-wave antenna in the UHF band is reported. The antenna is fabricated using low-cost materials and handmade techniques. This activity is intended for educational purposes and hands-on training of antenna engineering and related applications. Particularly, the proposed antenna can be used for localization of passive RFID tags and DVB-T base stations.IEEE APS (Antennas and Propagation Society) Educational Committee under the Educational Initiatives Program (EIP), and by Spanish National project PID2019-103982RB-C42

RSSI-Based direction-of-departure estimation in bluetooth low energy using an array of frequency-steered leaky-wave antennas

This paper presents a novel advanced Bluetooth Low Energy (BLE) beacon, which is based on an array of frequency-steered leaky-wave antennas (LWAs), as a transmitter for a Direction-of-Departure (DoD) estimation system. The LWA array is completely passive, fabricated in a low-cost FR4 printed-circuit board and designed to multiplex to different angular directions in space each one of the three associated BLE advertising channels that are used for periodically transmitting the ID of the beacon. This way, the use of more expensive hardware associated to electronic phased-array steering/beam-switching is avoided. Four commercial BLE modules are connected to the four ports of the array, producing an advanced BLE beacon that synthesizes twelve directive beams (one per each port and advertising channel) distributed over a wide Field of View (FoV) of 120 degrees in the azimuthal plane. Then, any BLE enabled IoT device located within this FoV can scan the messages from the beacon and obtain the corresponding Received Signal Strength Indicator (RSSI) of these twelve beams to estimate the relative DoD by using amplitude-monopulse signal processing, thus dispensing from complex In-phase/Quadrature (IQ) data acquisition or high computational load.We propose an angular windowing technique to eliminate angular ambiguities and increase the angular resolution, reporting a root mean squared angular error of 3.7º in a wide FoV of 120º.This work was supported in part by the Spanish National projects TEC2016-75934-C4-4-R and TEC2016-76465-C2-1-R, and in part by the 2018 UPCT Santander Research Grant

Compact Leaky-Wave SIW Antenna with Broadside Radiation and Dual-Band Operation for CubeSats

This letter presents a substrate-integrated waveguide (SIW) antenna for CubeSat applications. The compact structure utilizes middle-point feeding and shorting walls to achieve broadside radiation in the far-field at two distinct frequencies. In particular, this dual-frequency behaviour is related to the transition from a dominant leaky-wave (LW) on the aperture at lower frequencies to more hybrid radiation (at higher frequencies) due to LW fields and structure resonance due to truncation. This response is generated by the shorting vias at the lateral ends of the SIW antenna. Given these conditions, the developed leaky-wave antenna (LWA) prototype is well matched (|S11| -10 dB) from 23.2 to 23.5 GHz and 24.8 to 25.2 GHz with realized gains of 8 dBi and 6 dBi, respectively. Maximum efficiency (including the connector) is around 87%. Such dual-frequency operation could enable up-link and down-link operation in the K-band. Overall dimensions of the antenna are 20 x 2.60 (at the lower frequency). Possible placement on CubeSats can be underneath solar panels, thus increasing the available surface area for solar power harvesting. Also, to the best knowledge of the authors, no similar dual-frequency SIW-LWA has been previously reported

An array of leaky wave antennas for indoor smart wireless access point applications

An array of leaky-wave antennas (LWA), designed for indoor smart wireless access points applications is presented in this work. It is designed to produce directive frequency scanning in the 2.45 Wi-Fi band. More particularly, it is demonstrated how three different Wi-Fi channels, namely channel #1 (2.412 GHz), channel #6 (2.437 GHz), and channel #11 (2.462 GHz), can be directed towards different directions in space and offering high gain. In this way, it is proposed a simple channel-hopping technique to provide high signal levels in a wide area, and thus assure high data transmissions. The array is designed in single layer planar technology, using low-cost laminate to provide a low-profile antenna structure which can be mounted on ceilings.This work has been supported by Spanish national projects TEC2016-75934-C4-4-R and European Erasmus Grant KA107 Morocc

A mobile terminal leaky-wave antenna for efficient 5G communication

The millimeter-wave 37 –43.5GHz band is proposed to provide the requested multigigabit-per-second (Gb/s) data rates for future 5G cellular communications. As a total wireless-link gain of 37 dBi may be required, the mobile terminal antennas should provide 12 dBi gain –being the remaining 25 dBi for the base station antennas. This high gain is linked to the synthesis of narrow directive radiated beam, which must somehow be scanned into space over a wide field of view (FoV), and thus satisfy the mobility and coverage conditions. Such high-gain beam-scanning antenna design is very challenging, taking into account that high radiation efficiency, compact size/volume, and low-cost are key features for mass-market mm-wave applications. In this sense, most of the proposed 5G mobile-antenna solutions are based on phased arrays, which rely on active scanning/beam-forming networks which might be impractical due to an increase cost and manufacturing complexity. However, owning to their characteristics of high-gain, simple-feeding, planar structure, and inherent frequency-beam-scanning behavior, leaky-wave antennas (LWAs) might offer an interesting solution for high-gain low-cost scanning