Advanced System Technology

Capacitive measurement of very small displacement of nano-electro-mechanical systems (NEMS) presents some issues that are discussed in this article. It is shown that performance is fairly improved when integrating on a same die the NEMS and CMOS electronics. As an initial step toward full integration, an in-plane suspended gate MOSFET (SGMOSFET) compatible with a front-end CMOS has been developed. The device model, its fabrication, and its experimental measurement are presented. Performance obtained with this device is experimentally compared to the one obtained with a stand-alone NEMS readout circuit, which is used as a reference detection system. The 130 nm CMOS ASIC uses a bridge measurement technique and a high sensitive first stage to minimize the influence of any parasitic capacitances.

This paper describes the design of resonators using waves guided in a piezoelectric layer located above a Bragg mirror. Such a resonator is suitable for the intermediate frequency (IF) and high frequency (HF) ranges. In the IF (about 600 MHz) band, maximum quality factor is achieved when exploiting the second guided mode (analogous to the S 0 Lamb wave). In the HF band (about 2 GHz), a higher order mode (similar to the S 1 Lamb wave) provides high coupling factors.

This paper describes how to reduce spurious resonances which can take place in a resonator using guided waves above a Bragg mirror. These parasitics arise from overtone resonances as well as from higher order modes also excited by electrodes having inappropriate dimensions. In this paper, the influence of period and metalization ratio on the harmonic admittance of a resonator is studied.

This paper presents a bandpass filter for DCS/EDGE transmitter using bulk acoustic wave technology. It is designed to filter PA's harmonic frequencies and out-of-band noise generated by Sigma-Delta modulator in DCS/EDGE architecture. The filter is based on Solidly Mounted Resonators electrically coupled in a ladder type topology; it achieves 2.4 dB insertion loss including matching network to 50 Ω, more than 15 dB of return loss over the 75MHz DCS band. Linearity and power handling capability characterizations are detailed. This filter is combined with a Power Amplifier using STMicroelectronics' 0.25 µm BiCMOS technology, it is a first step to develop a Power Amplifier Module for GSM/EDGE standard in the DCS frequency band.

The monometallic species {Salen}AlX (X = Me, 2a,b; X= Cl, 4a,b; 5a,b) and open bimetallic species {Salen}A C H T U N G T R E N N U N G [AlMe 2 ] 2 (3a,b) that result from binary combinations between an aluminum precursor [trimethylaluminum, dimethylaluminum chloride, aluminum tris(isopropoxide)] and a diprotio {Salen}H 2 pro-ligand 1a,b (a = 1R,2R-cyclohexylsalen; b = 1R,2R-diphenylethylene-salen) have been isolated. The crystal structures of 3b, 4b and of m-oxo species [{diphenylethylene-salen}Al] 2 O (6b) are reported. The discrete species 2-5a,b have been individually evaluated in the asymmetric cyanosilylation of acetophenone. It is shown that, in several cases, these discrete catalysts display dramatically different performances than the catalyst systems in situ-generated from the binary combinations. The influence of the achiral ligand X on both the enantioselectivity and activity of the cyanosilylation reaction has been investigated, resulting in the definition of a highly active and productive hexafluoro-2-propoxide-based catalyst for a variety of aryl alkyl ketones (TON up to 470, TOF up to 140 h À1 at À20 8C for acetophenone).

The hydroalkoxylation of dicyclopentadiene (DCPD) and norbornene (NB) with 2-hy-A C H T U N G T R E N N U N G droxyethyl methacrylate (HEMA) for the synthesis of industrially relevant monomers has been investigated with various metal-based Lewis acids and strong Brønsted acids. In the absence of other additives, copper(II) triflate is the most efficient catalyst system. Kinetics, electron spin resonance (ESR), catalyst poisoning and cross experiments indicate that triflic acid (TfOH) is the true active catalyst in these reactions. This in situ generation of TfOH occurs via reduction of CuA C H T U N G T R E N N U N G (OTf) 2 by the olefin reagent (DCPD, NB). The copper ions present in the reaction mixture act as radical polymerization retardants, preventing polymerization of HEMA (which is observed with most other metal salts and strong Brønsted acids investigated), thus improving the selectivity and yield (up to 95%) for the desired products. These observations have led to the development of a highly effective green process, using bulk reagents (no solvent) and a cheap, metal-free catalyst system, based on TfOH and a phenolic radical inhibitor (2,5-di-tert-butylhydroxytoluene, BHT).