L. Marchand

Manufacturing Tolerance Analysis, Fabrication, and Characterization of 3-D Submillimeter-Wave Electromagnetic-Bandgap Crystals

The sensitivity of the characteristic band edge frequencies of three different 500-GHz electromagnetic-bandgap crystals to systematic variations in unit cell dimensions has been analyzed. The structures studied were square bar woodpiles made with dielectric having epsiv rap12 and epsivr=37.5 and two wide bandgap epsivr=37.5 crystals designs proposed by Fan and Johnson and Joannopoulos. These epsivr values correspond to high-resistivity silicon and a zirconium-tin-titanate ceramic, respectively. For the woodpiles, the fractional frequency bandgap varied very little for dimensional deviations of up to plusmn5% from the optimum. The bandgaps of the Fan and Johnson and Joannopoulos structures were affected to a greater extent by dimensional variations, particular sensitivity being exhibited to the air-hole radius. For all crystals, the effect of increasing the amount of dielectric in the unit cell was to shift the bandgap edges to lower frequencies. Both silicon and ceramic woodpiles, along with a ceramic Fan structure, were fabricated and dimensionally characterized. Mechanical processing with a semiconductor dicing saw was used to form the woodpiles, while the Fan structure required both dicing and UV laser drilling of circular thru-holes. Good agreement with predicted normal incidence transmissions were found on the low-frequency side of the bandgap in all cases, but transmission values above the upper band edge were lower than expected in the ceramic structures

Sub-Millimeter-Wave Imaging Array at 500 GHz Based on 3-D Electromagnetic-Bandgap Material

The design, fabrication, and characterization of a 500-GHz electromagnetic bandgap (EBG) based heterodyne receiver array is presented. The array contained seven planar dipole antennas that were photolithographically defined on a common 20-mum-thick quartz substrate. Each antenna incorporated a Schottky diode and was connected to coplanar transmission lines that conveyed the down-converted 500-GHz signals to detectors. The quartz substrate was backed by a silicon EBG woodpile structure, which reduced antenna crosstalk and increased directivity. An off-axis parabolic mirror completed the beam-forming network.

Gamma radiation effects on RF MEMS capacitive switches

Dielectric-based RF MEMS capacitive switches were fabricated and characterized for their response to dielectric charging, thermal storage and cycling and to total dose gamma irradiations. The evolution of the switch electromechanical and RF characteristics (actuation and releasing voltages, insertion losses, isolation) were evaluated as a function of the applied stress (temperature or total ionizing dose). It is indicated that the thermal stress has a relatively minor impact on the switches (the switches remained functional with nearly the same electrical properties). Under our particular test conditions, C(V) and S-parameters measurements show that gamma radiation has low to moderate effects on the components behavior.

Design and Test of a 0.5 THz Dipole Antenna With Integrated Schottky Diode Detector on a High Dielectric Constant Ceramic Electromagnetic Bandgap Substrate

This paper presents the first analysis of the input impedance and radiation properties of a dipole antenna, placed on top of Fan s three-dimensional electromagnetic bandgap (EBG) structure, (Applied Physics Letters, 1994) constructed using a high dielectric constant ceramic. The best position of the dipole on the EBG surface is determined following impedance and radiation pattern analyses. Based on this optimum configuration an integrated Schottky heterodyne detector was designed, manufactured and tested from 0.48 to 0.52 THz. The main antenna features were not degraded by the high dielectric constant substrate due to the use of the EBG approach. Measured radiation patterns are in good agreement with the predicted ones.

Total dose effects and SEE screening on MEMS COTS accelerometers

Two families of MEMS COTS are characterized for the total dose response, latch-up and SET sensitivity. These MEMS are microelectromechanical sensors: ADXL150 and SCA 600, which are fabricated with surface and bulk micromachining techniques.

Single Event Effects in MEMS Accelerometers

We present single event effects, induced by heavy ions and protons, on a COTS MEMS accelerometer. The testing procedure is outlined and the contributions from different parts of the accelerometer are discussed.

Optimization of a 500 GHz Receiver Using EBG Technology

The optimization of a 500 GHz receiver based on Electromagnetic Band Gap (EBG) technology is presented. The conguration consists of a dipole antenna placed on top of a woodpile structure and utilises a Schottky diode as the detecting element. The inuence of the diode and its substrate chip on the radiation performance has been studied, with the nding that it has to be placed as close as possible to the dipole antenna to avoid distorting the radiation pattern. Measurements are presented which conrm our simulations.

Simple creep parameters extraction in metal contact RF-MEMS switches

This paper presents a novel methodology for mechanical creep modeling in RF-MEMS. The devices are held in the down state and a servo loop maintains a constant contact resistance by varying the applied bias voltage. From this down state bias voltage variation, creep parameters, both from mechanical structure and contact area, are extracted. This method can be conducted on packaged commercial devices without needing any specific fabrication. This test can be used for rapid device screening and technology optimization.

Specific Characterization for Destructive Single Event Effects on GaAs Power P-HEMT MMIC

Specific Single Event Effects characterization based on RF and worst case DC conditions are used to demonstrate that two European GaAs power P-HEMT MMIC processes are safe under heavy ions.

Design and characterisation of an EBG imaging array at sub-millimetre wave frequencies

In this paper the design and characterisation of an imaging array at 500 GHz based on EBG technology is described. The array is formed by 7 detecting elements placed on a top of a silicon woodpile and uses a paraboloidal mirror as refractive element. Good agreement was obtained between predicted and measured performances.