A delay line phase shifter for the 30-70 GHz range is presented that uses an aluminum micro-ribbon array fabricated in the ground plane of a microstrip transmission line. Phase shift is achieved by changing the propagation velocity of an RF signal in the transmission line by controlling the effective permittivity of the substrate. This is done by actuating the micro-ribbons away from the substrate. This phase shifter has the benefits of analog phase shifts and high Figure of Merit. Simulations were done to model the micro-ribbon deflections, transmission line performance and phase shift. Arrays of 5, 10, and 20 μm wide micro-ribbons were fabricated and tested. At 40.80 GHz, the 20 μm wide micro-ribbons had a measured phase shift of 33º with an actuation voltage of 120 V. The corresponding Figure of Merit was a negative value indicating that there was no line loss due to ribbon deflection. / February 2008

A delay line phase shifter for the 30-70 GHz range is presented that uses an aluminum micro-ribbon array fabricated in the ground plane of a microstrip transmission line. Phase shift is achieved by changing the propagation velocity of an RF signal in the transmission line by controlling the effective permittivity of the substrate. This is done by actuating the micro-ribbons away from the substrate. This phase shifter has the benefits of analog phase shifts and high Figure of Merit. Simulations were done to model the micro-ribbon deflections, transmission line performance and phase shift. Arrays of 5, 10, and 20 μm wide micro-ribbons were fabricated and tested. At 40.80 GHz, the 20 μm wide micro-ribbons had a measured phase shift of 33º with an actuation voltage of 120 V. The corresponding Figure of Merit was a negative value indicating that there was no line loss due to ribbon deflection.

A delay line phase shifter for the 30-70 GHz range is presented that uses an aluminum micro-ribbon array fabricated in the ground plane of a microstrip transmission line. Phase shift is achieved by changing the propagation velocity of an RF signal in the transmission line by controlling the effective permittivity of the substrate. This is done by actuating the micro-ribbons away from the substrate. This phase shifter has the benefits of analog phase shifts and high Figure of Merit. Simulations were done to model the micro-ribbon deflections, transmission line performance and phase shift. Arrays of 5, 10, and 20 μm wide micro-ribbons were fabricated and tested. At 40.80 GHz, the 20 μm wide micro-ribbons had a measured phase shift of 33º with an actuation voltage of 120 V. The corresponding Figure of Merit was a negative value indicating that there was no line loss due to ribbon deflection.

Il y a à l'heure actuelle un grand besoin en systèmes et composants agiles pour les dispositifs front-end RF. Dans cette thèse, deux approches innovantes sont développées pour la conception de tels dispositifs RF. Dans un premier temps, un mécanisme de reconfiguration micro-mécanique est développé. Cette approche vise à contrôler la hauteur d'un gap d'air inséré dans le substrat de composants microrubans afin d'en modifier les dimensions électriques. Les choix de conception et la fabrication d'un déphaseur à ligne micro-ruban ainsi que d'une antenne accordable en fréquence sont discutés. Une solution d'actionnement piézoélectrique basse tension (+/- 30 V) est retenue. La figure de mérite obtenue dans le cas du déphaseur atteint jusqu'à 313 °/dB ce qui dépasse l'état de l'art en matière de déphasage analogique. Dans le cas de l'antenne, le potentiel d'agilité en fréquence atteint 35 % autour d'une fréquence centrale de 55 GHz. Contrairement aux solutions classiques à base de semiconducteurs ou de RF-MEMS, ce mécanisme de reconfiguration n'impacte pas les performances de l'antenne dont l'efficacité de rayonnement est proche de 94 %. Dans un second temps, c'est un mécanisme micro-fluidique qui est étudié. L'agilité en fréquence d'antennes est créée par l'écoulement successif de liquides de permittivités différentes dans des micro-canaux intégrés au substrat. L'accord en fréquence atteint alors la très large ampleur de 51 % pour une fréquence centrale de 22 GHz. Cette étude s'accompagne de la recherche et caractérisation diélectrique de plusieurs fluides dans l'optique d'augmenter aussi bien la plage d'accord en fréquence que les performances de rayonnement des antennes / As wireless networks evolve, the frequency bands they exploit multiply. Frequency multiplexing, beamforming and tracking, networks interoperability, those mutations increase the need for agility and tunability in the RF-front end systems. In this thesis, two innovative approaches for the design of tunable RF components are studied. First, a micro-mechanical reconfiguration mechanism is developed. This approach means to control the height of an air gap within the substrate of microstrip components in order to control their electrical dimensions. Considerations for the design and fabrication of a phase-shifter and a frequency tunable patch antenna are made and a low voltage piezoelectric actuation (+/- 30 V) is chosen. The phase-shifter figure of merit reaches up to 312 °/dB which is beyond the state of the art in terms of analogic phase-shifting. Regarding the antenna, the frequency tuning potentially reaches up to 35 \% of a central frequency of 55 GHz. Unlike the classic solidstate or RF-MEMS based solutions, this reconfiguration mechanism does not impact the radiation performance of the antenna whose radiation efficiency is 94 \%. In a second approach, a micro-fluidic solution is studied. Frequency tuning capability is created in different antennas by the flow of successive liquids with different permittivities in integrated micro-channels. A large frequency tuning of 51 \% for a central frequency of 22 GHz is achieved. This study goes along with the search and characterization of several fluids with the objective of increasing both the frequency shift and the radiation performance of those antennas