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dc.contributor.advisorMedina-Sánchez, Rafael H.
dc.contributor.authorAlvelo-Rivera, Enrique M.
dc.date.accessioned2019-04-23T19:57:17Z
dc.date.available2019-04-23T19:57:17Z
dc.date.issued2018-05
dc.identifier.urihttps://hdl.handle.net/20.500.11801/2097
dc.description.abstractThe market outlook for upgrade, expansion and new acquisition of military UAS equipment exhibits substantial potential to grow during the 10 year period extending from year to year . Some of the mission characteristics and requirements that will drive future UAS development include: continuing microminiaturization, sensor fusion, command, control & communications standardization, and infrastructure integration to achieve smaller, less costly and more capable UAVs. Hence, an increased market demand for research & development of UAS antenna systems is also expected during the same 10 year period. The University of Puerto Rico at Mayagüez is currently developing a “Hybrid Mechanical/ Electronic Steerable Antenna Array for SATCOM Terminals” to help enable significant efficiency and endurance improvements in future UAS platforms. The thesis “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” presented in this document complements the development project of the “Hybrid Mechanical/ Electronic Steerable Antenna Array for Terminals” that will operate in the extended Ku – band frequency range. Furthermore, the “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” provides a fundamental unit cell that enables the development of a beamformer network module that minimizes risks of fabrication errors, simplifies operation & maintenance tasks and provides roll-out flexibility for future antenna system expansions. The microwave circuit included in the “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” consists of one driver amplifier, one 1:2 coupler, two variable phase shifters, one hybrid coupler and two power amplifiers interconnected by microstrip line structures. Simultaneous one dimensional electronic beam steering and polarization tilt rotation might be achieved by electronically adapting the phase shifts provided by both transmission paths to help mitigate the effects of adjacent satellite interference. According to simulation results the overall performance of the “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” meets relevant requirements of key commercial, military and industrial standard specifications available to the general public as unclassified or declassified information. However, it was observed that the predicted polarization axial ratio performance partially complies with MIL-STD-188- 164B standard specifications regarding amplitude variations of the transmission uplink function and linear polarization axial ratio for Ku-band systems using antennas with diameters smaller or equal to . The highest extent of polarization axial ratio degradation was observed at the interconnection between the output ports of the phase shifters and the input ports of the hybrid coupler. The theoretical model developed as part of this research project confirmed that the polarization axial ratio performance suffers severe degradation mainly caused by the introduction of amplitude errors. Hence, variable attenuators were presented as the most practical solution to enable the required amplitude compensation to mitigate the effects of amplitude errors on gain ripple and polarization axial ratio performance.
dc.description.abstractTransmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” proporciona una celda unitaria fundamental que permite el desarrollo de un módulo de red de formación del haz de transmisión que reduce al mínimo los riesgos de errores de fabricación, simplifica las tareas de operación y mantenimiento, en adición a proporcionar flexibilidad en el despliegue de expansiones futuras del sistema de antenas. El circuito de microondas incluido en la tesis “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” consta de un amplificador de mediana potencia, dos desfasadores variables, un acoplador de potencia 1:2, un acoplador híbrido de 90° y dos amplificadores de alta potencia interconectados por estructuras compuestas de líneas de transmisión de tipo microcinta. El direccionamiento electrónico, unidimensional, del haz de radiación y la rotación de la inclinación de la polarización de la onda pueden lograrse simultáneamente adaptando electrónicamente los cambios de fase proporcionados en ambos pasos de transmisión para ayudar a mitigar los efectos de interferencia de satélites adyacentes. De acuerdo a los resultados de simulaciones, el rendimiento global de la tesis “Design of a Polarization Adaptive Beamforming Transmitter Sub-Array for Beyond Line of Sight Satellite Communications in Unmanned Aircraft Systems” cumple con los requisitos pertinentes de especificaciones claves de estándares comerciales, militares e industriales disponibles al público en general como información no clasificada o desclasificada. Sin embargo, se observó que el rendimiento de la razón axial de polarización prevista cumple parcialmente con especificaciones de estándar MIL-STD- 188-164B con respecto a las variaciones de amplitud de la función de transmisión del enlace ascendente y la razón axial de polarización lineal para sistemas de banda Ku que utilizan antenas de diámetro menor o igual a 2.5 m. El más alto grado de degradación de la razón axial de polarización se observó en la interconexión entre los puertos de salida de los desfasadores y los puertos de entrada del acoplador híbrido. El modelo teórico desarrollado como parte de este proyecto de investigación confirmó que el rendimiento de la razón axial de polarización sufre una degradación severa causada principalmente por la introducción de errores de amplitud. Por lo tanto, la implementación de atenuadores variables fue presentada como la solución más práctica para permitir la compensación de amplitud necesaria para mitigar los efectos de los errores de amplitud en el rendimiento de la ondulación en la ganancia y la razón axial de polarización.
dc.description.sponsorshipPuerto Rico Science, Technology and Research Trusten_US
dc.language.isoenen_US
dc.subjectSatellite communications - Drone aircraft - Microwave circuiten_US
dc.subjectAntenna arrays - Improve drone aircraft - Mayaguez, P. R.en_US
dc.subject.lcshBeamformingen_US
dc.subject.lcshDrone aircraft--Control systemsen_US
dc.subject.lcshAntenna arraysen_US
dc.titleDesign of a polarization adaptive beamforming transmitter sub-array for beyond line of sight satellite communications in unmanned aircraft systemsen_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2018 Enrique M. Alvelo - Riveraen_US
dc.contributor.committeeColom - Ustáriz, José
dc.contributor.committeeCruz - Pol, Sandra
dc.contributor.committeeRodríguez - Solís, Rafael A.
dc.contributor.representativePadilla, Ingrid Y.
thesis.degree.levelM.S.en_US
thesis.degree.disciplineElectrical Engineeringen_US
dc.contributor.collegeCollege of Engineeringen_US
dc.contributor.departmentDepartment of Electrical and Computer Engineeringen_US
dc.description.graduationSemesterSpringen_US
dc.description.graduationYear2018en_US


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    Items included under this collection are theses, dissertations, and project reports submitted as a requirement for completing a degree at UPR-Mayagüez.

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