000213240 001__ 213240
000213240 005__ 20190509132529.0
000213240 0247_ $$2doi$$a10.5075/epfl-thesis-6781
000213240 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis6781-3
000213240 02471 $$2nebis$$a10540193
000213240 037__ $$aTHESIS
000213240 041__ $$aeng
000213240 088__ $$a6781
000213240 245__ $$aMulti-band reflectarray antennas in Ku and THz frequency bands
000213240 260__ $$bEPFL$$c2015$$aLausanne
000213240 269__ $$a2015
000213240 300__ $$a144
000213240 336__ $$aTheses
000213240 500__ $$aCo-supervision with: Instituto Superior Técnico (IST) da Universidade de Lisboa, Instituto de Instituto de telecomunicações, Doutoramento em Engenharia Electrotécnica e de Computadores
000213240 502__ $$aDr Sidi-Rachid Cherkaoui (président) ; professeure Anja Skrivervik Favre, Prof. Custódio José de Oliveira Peixeiro (directeurs) ; Dr Farhad  Rachidi, Prof. José Antonio Encinar, Prof. Özlem Aydin Çivi (rapporteurs)
000213240 520__ $$aPrinted reflectarrays are low-cost, low-profile high gain antennas demonstrating distinctive advantages over conventional parabolic reflectors and phased-arrays. The flat, low weight reflecting surface of a reflectarray makes it an attractive alternative with respect to bulky parabolic reflectors specially for space and satellite systems. As compared to high-cost phased-array antennas, with incorporation of solid state devices, reflectarrays are able to demonstrate electronic beam scanning in a very low-cost way. A distinctive advantage of a reflectarray antenna lies in its potential to be readily designed as a multi-band antenna which demonstrates independent performance at several frequencies. A characteristic that is difficult to achieve using conventional parabolic reflectors. The aim of this thesis is to present low-cost, simple, multi-band printed reflectarray antennas in Ku and THz frequency bands. In Ku band we present a dual-band reflectarray performing at 12 and 14 GHz and a quad-band reflectarray antenna performing at 12, 13, 14 and 15.5 GHz. The presented prototypes benefit from the advantage of having a single-layer structure which reduces the design complexity as well as the fabrication cost. In addition, multi-band reflectarrays are able to perform at any polarization due to the dual-linear polarized design of their unit-cells. Furthermore, the design of the unit-cell is such that, at each frequency, the phase response depends on only one parameter of the cell. This advantage eliminates the need for time consuming optimizations. Based on proposed unit-cells dual-band and quad-band reflectarrays with arbitrary beam direction versus frequency have been simulated, fabricated and measured. Simulation and measurement results as well demonstrate the satisfactory independent performance of the prototypes at each intended frequency. In THz region, for the first time we present a tri-band unit-cell based on which reflectarray prototypes performing at the three frequencies 0.7, 1.0 and 1.5 THz, are designed. The presented reflectarrays possess all the advantages of those designed for Ku band with the additional advantage of having high resistivity silicon as the substrate thanks to a sophisticated fabrication process. The use of silicon as substrate is a big advantage since it facilitates the integration of solid state devices for reconfigurability. Based on the proposed unit-cell reflectarray samples with arbitrary independent performance at each frequency are designed, simulated, fabricated and measured. Measurement results obtained using a THz-TDS (Terahertz Time-Domain Spectroscopy) measurement system, demonstrate the satisfactory independent performance of the reflectarray samples at each frequency. This thesis also presents a dual-band, dual-polarized reconfigurable unit-cell for beam-scanning reflectarray operating at 12 and 14 GHz. The cell however suffers from high-cross-polarization level. A chessboard cell arrangement is proposed to mitigate the high cross-polarization level at the reflectarray far-field region. Simulation results show the effectiveness of the chessboard arrangement in eliminating the cross-polarization allowing the design of a low-cross polarization reconfigurable reflectarray antenna out of a unit-cell with high cross-polarization level. Finally, the thesis presents the concept of a versatile flat prism which is a reflectarray with a pre-designed frequency-scanning behaviour. The limitations and challenges as well as solutions for implementation of such a device are presented and discussed.
000213240 6531_ $$aKu band
000213240 6531_ $$aTHz
000213240 6531_ $$aDual polarization
000213240 6531_ $$aReflectarray
000213240 6531_ $$aPeriodic structures
000213240 6531_ $$aMetasurfaces
000213240 6531_ $$aMutli-band
000213240 6531_ $$aHigh gain antennas
000213240 6531_ $$aSatellite communications
000213240 6531_ $$aReconfigurable antennas
000213240 700__ $$0246739$$g204521$$aHasani, Hamed
000213240 720_2 $$aSkrivervik, Anja$$edir.$$g106441$$0242772
000213240 720_2 $$aPeixeiro, Custódio$$edir.
000213240 8564_ $$uhttps://infoscience.epfl.ch/record/213240/files/EPFL_TH6781.pdf$$zn/a$$s18365775$$yn/a
000213240 909C0 $$xU10374$$0252091$$pLEMA
000213240 909CO $$pthesis-bn2018$$pDOI$$ooai:infoscience.tind.io:213240$$qDOI2$$qGLOBAL_SET$$pthesis
000213240 917Z8 $$x108898
000213240 917Z8 $$x108898
000213240 917Z8 $$x108898
000213240 917Z8 $$x108898
000213240 918__ $$dEDEE$$cIEL$$aSTI
000213240 919__ $$aLEMA_2015
000213240 920__ $$b2015$$a2015-10-30
000213240 970__ $$a6781/THESES
000213240 973__ $$sPUBLISHED$$aEPFL
000213240 980__ $$aTHESIS