Umer Javed Shah

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This paper reports on two novel concepts of area-efficient ultra-wideband microelectromechanical systems (MEMS) reconfigurable coupled line directional couplers, whose coupling is tuned by mechanically changing the geometry of 3-D micromachined coupled transmission lines, utilizing integrated MEMS electrostatic actuators. Concept 1 is based on symmetrically(More)
This paper presents a novel concept of RF microelectromechanical systems (MEMS) tunable capacitors based on the lateral displacement of the sidewalls of a 3-D micromachined coplanar transmission line. The tuning of a single device is achieved in multiple discrete and well-defined tuning steps by integrated multi-stage MEMS electrostatic actuators that are(More)
This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30 μm thick and consists of up to 1260(More)
This paper presents for the first time MEMS tuneable filters, where the reconfiguration of the filter is achieved by moving the sidewalls of a 3D micromachined transmission line. The sidewalls of the transmission line are moved by MEMS electrostatic actuators completely integrated into the ground layers of a thick-film coplanar waveguide. Multi-step(More)
This paper presents a 500-750 GHz waveguide based single-pole single-throw (SPST) switch achieving a 40% bandwidth. It is the first ever RF MEMS switch reported to be operating above 220 GHz. The switch is based on a MEMSreconfigurable surface which can block the wave propagation in the waveguide by short-circuiting the electrical field lines of the TE10(More)
This paper presents the characterization of integrated micromachined waveguide absorbers in the frequency band of 220 to 325 GHz. Tapered absorber wedges were cut out of four different commercially available semi-rigid absorber materials and inserted in a backshorted micromachined waveguide cavity for characterization. The absorption properties of these(More)
This paper describes the main results of the EU FP7 project TUMESA - MEMS tuneable metamaterials for smart wireless applications. In this project, we studied several reconfigurable antenna approaches that combine the new technology of MEMS with the new concept of artificial electromagnetic materials and surfaces (metamaterials and metasurfaces) for(More)
This paper investigates an implementation of RF MEMS tuneable capacitors based on the lateral displacement of the sidewalls of a three-dimensional micromachined coplanar transmission line. The concept achieves high Q since the mechanical actuation elements are completely de-coupled from the RF path, which is achieved by capacitive coupling of the ground(More)
This paper gives an overview on recent achievements in micromachined technology for millimeter and submillimeter-wave applications, from 130 to 750 GHz. The micromachined components presented include the first ever submillimeter-wave MEMS devices, namely a 500600 GHz 3.3 bit phase shifter and a 500-750 GHz waveguide MEMS switch, a 0.02 dB/mm loss waveguide(More)
This paper reports on area-efficient, ultrawideband, MEMS-reconfigurable directional couplers, whose coupling is tuned by mechanically changing the geometry of 3D-micromachined coupled transmission lines, utilizing integrated MEMS electrostatic actuators. Devices have been fabricated in an SOI RF MEMS process. Furthermore, to the best knowledge of the(More)