An ohmic RF MEMS switch for reconfigurable microstrip array antennas built on PCB

This paper presents the analysis, design and simulation of an ohmic RF MEMS switch specified for reconfigurable microstrip array antennas built on PCB via an integrated monolithic technology. The proposed switch will be used to allow antenna beamforming in the operating frequency range between 2.4GHz and 4GHz. This application requires a great number of these switches to be integrated with an array of microstrip patch elements. The proposed switch exhibits outstanding switching characteristics, following a relatively simple design, which ensures reliability, robustness and high fabrication yield

On the design of an Ohmic RF MEMS switch for reconfigurable microstrip antenna applications

This paper presents the analysis, design and simulation of a direct contact (dc) RF MEMS switch specified for reconfigurable microstrip array antennas. The proposed switch is indented to be built on PCB via a monolithic technology together with the antenna patches. The proposed switch will be used to allow antenna beamforming in the operating frequency range between 2GHz and 4GHz. This application requires a great number of these switches to be integrated with an array of microstrip patch elements. The proposed switch fulfills the switching characteristics as concerns the five requirements (loss, linearity, voltage/power handling, small size/power consumption, temperature), following a relatively simple design, which ensures reliability, robustness and high fabrication yiel

Monolithic MEMS quadrupole mass spectrometers by deep silicon etching

Published versio

Static and dynamic characterization of pull-in protected CMOS compatible poly-SiGe grating light valves

status: publishe

Micro-Electro-Mechanical-Systems (MEMS) and Fluid Flows

The micromachining technology that emerged in the late 1980s can provide micron-sized sensors and actuators. These micro transducers are able to be integrated with signal conditioning and processing circuitry to form micro-electro-mechanical-systems (MEMS) that can perform real-time distributed control. This capability opens up a new territory for flow control research. On the other hand, surface effects dominate the fluid flowing through these miniature mechanical devices because of the large surface-to-volume ratio in micron-scale configurations. We need to reexamine the surface forces in the momentum equation. Owing to their smallness, gas flows experience large Knudsen numbers, and therefore boundary conditions need to be modified. Besides being an enabling technology, MEMS also provide many challenges for fundamental flow-science research

Miniature Sensor Node with Conformal Phased Array

This paper reports on the design and fabrication of a fully integrated antenna beam steering concept for wireless sensor nodes. The conformal array circumcises four cube faces with a silicon core mounted on each face. Every silicon core represents a 2 by 1 antenna array with an antenna element consisting of a dipole antenna, a balun, and a distributed MEMS phase shifter. All these components are based on a single wafer process and designed to work at 17.2 GHz. Simulations of the entire system and first results of individual devices are reported

Reconfigurable Reflectarrays and Array Lenses for Dynamic Antenna Beam Control: A Review

Advances in reflectarrays and array lenses with electronic beam-forming capabilities are enabling a host of new possibilities for these high-performance, low-cost antenna architectures. This paper reviews enabling technologies and topologies of reconfigurable reflectarray and array lens designs, and surveys a range of experimental implementations and achievements that have been made in this area in recent years. The paper describes the fundamental design approaches employed in realizing reconfigurable designs, and explores advanced capabilities of these nascent architectures, such as multi-band operation, polarization manipulation, frequency agility, and amplification. Finally, the paper concludes by discussing future challenges and possibilities for these antennas.Comment: 16 pages, 12 figure

Fabrication of mixed-scale PMMA (Polymethyl methacrylate) fluidic device via thermal nanoimprint using a convex carbon mold

Department of Mechanical EngineeringRecently micro-/nanofluidic devices are widely used for various research areas including biological, chemical, and biomedical applications. Such mixed-scale micro-/nanofluidic devices are generally fabricated using photolithography and direct writing methods (e. g., e-beam lithography or focused ion beam milling) in series. However, the direct writing methods require high cost and long process time thus resulting in low throughput issue. PDMS (Polydimethylsiloxane) replication can overcome the low throughput issues. The PDMS replication method consists of a PDMS casting process on a pre-patterned mold and a subsequent curing processes. By this method, PDMS mixed-scale channel patterns can be replicated repeatedly, thus, total throughput of fabricated mixed-scale PDMS fluidic device is enhanced. However, the channel size is smaller, the more PDMS channels are collapsed due to the low Young???s modulus and hardness of PDMS. In this study, I developed the fabrication method of mixed-scale PMMA (Poly methyl methacrylate) fluidic device via simple thermal nanoimprint using a monolithic mixed-scale convex carbon mold (microchannel mold: width = ~ 50 ???m, height = ~ 5 ???mnanochannel mold: width = ~ 600 nm, height = ~ 60 nm). The monolithic carbon mold was fabricated using carbon-MEMS consisting of two step photolithography processes and one step pyrolysis. In pyrolysis, polymer structures shrank dramatically and thus microscale photoresist structures were converted into sub-micro- or nanoscale carbon structures. In nanoimprint process, the shape of the monolithic mixed-scale convex carbon mold was transferred into a PMMA sheet while the polymer sheet was heated. After demolding the carbon mold from the patterned PMMA sheet, the patterns were accurately transferred on the PMMA sheet (microchannel: width = ~ 50 ???m, height = ~ 5 ???mnanochannel: width = ~ 600 nm, height = ~ 60 nm). The pyrolyzed carbon mold could be easily demolded because of its curved side walls resulting from anisotropic volume reduction in pyrolysis. This special side wall geometry and good robustness of the carbon mold ensured reproducibility in nanoimprint. The mixed-scale channels were sealed by another thin PMMA sheet with low pressure and heat after oxygen plasma treatment. PMMA has higher Young???s modulus compared to PDMS (polydimethylsiloxane) so that the PMMA channels ensured consistent nanochannel fabrication and operation without channel collapse. The PMMA mixed-scale fluidic device was used to entrap single particles via diffusiophoresis. In the fluidic device, microchannels and nanochannels were smoothly connected via Kingfisher-beak-shaped 3D microfunnels that were converted from polymer triangular prims via pyrolysis. By filling two microchannels that are connected via multiple nanochannels with high concentration solution and low concentration solution respectively and controlling pressure difference between two microchannels, local concentration gradients can occur near the 3D microfunnels at the microchannel with low concentration. The localized concentration gradients generate local electric fields resulting in diffusiophoresisthe motion of charged particles along the localized electric fields. In this experiment, 1 ??m-diameter charged single particles dispersed in the low concentrate solution were dragged from the microchannel into the 3D microfunnels via diffusiophoresis. Consequently, the unique 3D microfunnel worked as a chamber where single particle was entrappedthus, single particles could be entrapped without external electric force in 3D microfunnels. The diffusiophoresis-based single particle entrapment experiment showed the potential of the mixed-scale channel networks as a single cell research tool.ope