Ka-band MMIC beam steered transmitter array

A 32-GHz six-element linear transmitter array utilizing monolithic microwave integrated circuit (MMIC) phase shifters and power amplifiers was designed and tested as part of the development of a spacecraft array feed for NASA deep-space communications applications. Measurements of the performance of individual phase shifters, power amplifiers, and microstrip radiators were carried out, and electronic beam steering of the linear array was demonstrated. The switched-line phase shifters were accurate to within 7 percent on average and the power amplifier 1-dB compressed output power varied over 0.3 dB. The array had a beamwidth of 7.5 deg and demonstrated acceptable beam steering over + or - 8 deg. From the results, it can be concluded that this MMIC phased array has adequate beam-scanning capability for use in the two-dimensional array. The areas that need to be improved are the efficiency of the MMIC power amplifier and the insertion loss of the MMIC phase shifter

SOI technology for single-chip harsh environment microsystems

Silicon-on-Insulator (SOI) technology is emerging as a major contender for heterogeneous microsystems applications. It is indeed well known that SOI CMOS integrated circuits yield quasi-ideal properties for micropower and RF functionalities, as well as for high-temperature operation up to e.g. 350DGC. In addition SOI substrates offer unique opportunities for implementing sensors and MEMS. Such devices and circuits can further be combined to co-integrate high-performance intelligent/smart micro-systems on a single SOI substrate. The present talk will report recent SOI developments of thin-film Si sensors (temperature, magnetic, UV) and thin dielectric membranes (flow, gas, pressure) as well ultra-low-power/high-temperature CMOS circuits, of potential interest for aerospace applications (e.g. structural or environmental monitoring). Future possibilities of multi-SOI substrates will also be discussed

Feasibility and limits of wi-fi imaging

We explore the feasibility of achieving computational imaging using Wi-Fi signals. To achieve this, we leverage multi-path propagation that results in wireless signals bounc-ing off of objects before arriving at the receiver. These re-flections effectively light up the objects, which we use to per-form imaging. Our algorithms separate the multi-path reflec-tions from different objects into an image. They can also ex-tract depth information where objects in the same direction, but at different distances to the receiver, can be identified. We implement a prototype wireless receiver using USRP-N210s at 2.4 GHz and demonstrate that it can image objects such as leather couches and metallic shapes in line-of-sight and non-line-of-sight scenarios. We also demonstrate proof-of-concept applications including localization of static hu-mans and objects, without the need for tagging them with RF devices. Our results show that we can localize static hu-man subjects and metallic objects with a median accuracy of 26 and 15 cm respectively. Finally, we discuss the limits of our Wi-Fi based approach to imaging

Sensing and MEMS Devices in Thin-Film SOI MOS Technology

Silicon-on-Insulator (SOI) technology is emerging as a major contender for heterogeneous microsystems applications. In this work, we demonstrate the advantages of SOI technology for building thin-film field-effect biosensors and optical detectors, physical and chemical sensors on thin dielectric membrane as well as three-dimensional (3D) microelectromechanical (MEMS) sensors and actuators. The flatness and robustness of the thin membrane as well as the self-assembling of 3D microstructures rely on the chemical release of the microstructures and on the control of the residual stresses building up in multilayered structures undergoing a complete thermal process. The deflection of multilayered structures made of both elastic and plastic thin films results from the thermal expansion coefficient mismatches between the layers and from the plastic flow of a metallic layer. The proposed CMOS-compatible fabrication processes were successfully applied to suspended sensors on thin dielectric membranes such as gas-composition, gas-flow and pressure sensors and to 3D self-assembled microstructures such as thermal and flow sensors