Experimental Study of an Adding Interferometer at Millimeter Waves

In order to study an original detection architecture for future cosmology experiments based on wide band adding interferometry, we have tested a single baseline bench instrument based on commercial components. The instrument has been characterized in the laboratory with a wide band power detection setup. A method which allows us to reconstruct the complete transfer function of the interferometer has been developed and validated with measurements. This scheme is useful to propagate the spurious effects of each component till the output of the detector.     

High mobility p-channel organic field effect transistors on flexible substrates using a polymer-small molecule blend

Organic field effect transistors have been fabricated on poly(ethylene terephthalate) film substrates with excellent operating characteristics and maximum mobilities of 1.1 cm²/(V s). The semiconductor was a solution processible blend of 6,13-bis(triisopropyl silylethynyl) pentacene and a poly(triaryl amine) used to combine the favourable properties of small molecules and polymers. We have demonstrated that such systems are a good candidate for flexible organic electronics and that the surface energy of the substrate plays a key role in controlling the morphology of the semiconductor film.     

UHV CAFM characterization of high-k dielectrics: Effect of the technique resolution on the pre- and post-breakdown electrical measurements

In this work, a Conductive Atomic Force Microscopy (CAFM) working in contact mode has been used to compare the measured electrical properties and breakdown (BD) on ultra thin high-k dielectrics, when different environmental conditions are used. In particular, the effect of the environment on the conductivity measurements, the lateral resolution in current images and the lateral propagation of the BD event will be analyzed in air, dry nitrogen (N₂) and Ultra High Vacuum (UHV).     

High performance GaAs MESFETs with molecular implanted and optimized lowly-doped drain structure for maximized speed, gain and breakdown performance

GaAs MESFETs with novel lowly-doped drain structures have been developed utilizing molecular implants of silicon trifluoride. Short-channel effects in the 1/4 μm enhancement- and depletion-mode transistors have been suppressed with drain-induced barrier height lowering of less than 70 mV/V and pinch-off voltage shifts of less than 220 mV as the gate length was scaled from 1.0 to 1/4 μm. The 3-terminal breakdown, the transconductance to output conductance ratio, and the unity current gain, cut-off frequency were simultaneously optimized. The E-mode device possessed breakdown of >10 V, G_m · R_ds > 9.5, F_t > 55 GHz, and nominal on-resistance of 2.1 Ω mm while the D-mode device had breakdown >10 V, G_m · R_ds > 6.0, F_t > 45 GHz, and nominal on-resistance of 1.9 Ω mm. These optimized transistors enabled the realization of a variety of low-power digital and high-power mixed signal circuits, using 3-level source-coupled transistor and common-mode logic, such as laser and electro-optic drivers, highly integrated transceivers, multiplexers, demultiplexers, and clock data recover circuits.     

The pedagogic paradox (or why no didactics in England?)

This article has been written for two purposes. First, it explores a paradox: that recent Anglo-American usage of 'pedagogy' mirrors the mainland European use of 'didactic'. Secondly, it is a comment on the current status of curriculum studies. In particular, it relates curriculum analysis to the fields of didactic and pedagogic analysis.