J. Costa Freire

The authors present an experimental method for the characterization of MOS power switching transistors that does not involve technological parameters that are not available to designers. The method is based on the time-domain analysis of the commutation performance of the transistor when constant current are injected into its terminals. The analysis of the time-domain waveforms and the knowledge of the internal structure of the MOS devices are sufficient for the evaluation of the transistor capacitances. It is then possible to introduce a simple large-signal model for power MOSFETs that is particularly well suited to the analysis of circuits using the MOS transistor in commutation (e.g., switching power converters or high-efficiency power amplifiers). The authors also present the model implementation in the SPICE 2 program. Comparison between results obtained experimentally and by computer simulation for several circuits confirms the accuracy of the proposed method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This paper presents a 1.7-mW low-intermediate-frequency receiver design for Bluetooth low-energy (BLE) applications. The design exploits particular aspects of BLE, such as the relaxed in-band interference characteristics, more precisely the C/I <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> MHz, and the relatively high-frequency-shift keying modulation index, to deliver a high level of energy efficiency and simplicity to the receiver baseband architecture. Reliable quadrature signals are generated in the RF signal path without consuming energy, which is supported by an inverter-based low-noise amplifier (LNA) that achieves high gain and low noise figure under low-power budgets. A small-signal analysis of low-power inverter-based LNAs is presented offering simple design equations. Seeking an affordable solution, the fabricated prototype is fully integrated into an earlier generation CMOS technology node (0.13 μm), occupying a silicon area smaller than 0.7 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The receiver achieves a sensitivity level of -92 dBm while consuming 1.41 mA from a 1.2-V supply.

A comparison of single-pole single-throw switch topologies is presented in this paper. A three-MESFET monolithic GaAs switch was designed, for 2-GHz operation, fabricated and tested in three different bias conditions: V/sub bias/ = 0 (self-bias); I/sub bias/ = 0 (floating); and V/sub bias/ /spl ne/ 0, I/sub bias/ /spl ne/ 0 (biased). It will be shown that a floating configuration presents on-state lower insertion loss (IL) (/spl sim/1.7 dB). However, the off-state isolation has the same order of magnitude in all three bias conditions (typically 50 dB). Comparing measurements and simulations, the best available nonlinear model for the floating bias operation was selected. Finally, several resonant topologies were studied and a new topology is proposed to increase the off-state isolation without degrading the on-state IL. The advantages and drawbacks of resonant topologies over nonresonant configurations are also discussed, taking into account technology constraints and operation frequency. A solution to reduce the inductor value is proposed.

This paper deals with the improvement on low cost LTCC technology to achieve the specifications of planar filters for a 30GHz Satellite system transmitter. Test structures were fabricated on low cost LTCC technology, presently available for lower frequencies, to characterise its performances up to 40GHz. From this study, guidelines for the design of 30GHz circuits were obtained. Based on these results and their constraints, several solutions for a 30GHz transmitter filter were designed. A comparison between the LTCC filters with active and passive alternative solutions implemented on GaAs monolithic technology is also presented. The feasibility of millimeterwave filters on LTCC with a reasonable yield for mass production is demonstrated.

An overview of microwave activities and infrastructures in Europe is presented. The material is organized in 17 sections, each devoted to a country or group of countries and prepared by an. internationally renowned microwave expert. In general, each section contains some history of microwaves in the region, and highlights some microwave activities in association with research centers, laboratories and institutions, industry, education, and national conferences.