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This article describes field test results of hybridization between MEMS inertial measurement unit (IMU) and GPS L1 C/A signal using an ultra-tight coupling (UTC) architecture. A software receiver is used to post-process raw GPS signal and IMU measurement recorded during the field tests. Both indoor and outdoor environments are explored and UTC with MEMS is compared to UTC with high-grade IMU and vectorized GNSS standalone positioning.

The goal of this paper is to present the architecture and first performance results of the DINGPOS platform. The DINGPOS platform (Demonstrator for INdoor GNSS POSitioning) is a project funded by the ESA that covers the design, development and integration of an experimental indoor positioning system based on the fusion of three different technologies: High Sensitivity GNSS (GPS and the future Galileo), MEMS-based Pedestrian Navigation System and WIFI. This paper introduces the different architectural trade-offs of the final platform and presents the first results of its performance and capabilities with real data.

Self-heating of bipolar transistors can lead to a significant increase of their junction temperature. This must be correctly considered for accurate modeling and also to ensure reliability. Because of this, several measurement techniques for thermal resistance extraction were proposed in the literature. However, a drawback of most methods is that they require measurements at different ambient temperatures for each device. This is very tedious if a large number of different transistors must be investigated. Therefore, we present a new technique that allows extraction of the thermal resistance from simple measurements carried out at only one ambient temperature, based on previously determined technology-specific data. Moreover, as a byproduct, the emitter resistance is estimated. The validity of this method is demonstrated here for SiGe HBTs, but it has also been used successfully for GaAs HBTs.

Intensive world wide development work in high-speed bipolar RF technologies leads to a rapid increase in transistor performance. This paper describes a manufacturable leading-edge 0.35 /spl mu/m bipolar SiGe:C technology offering balanced transistor parameter sets with more than 150 GHz f/sub T/ and 180 GHz f/sub max/ as well as further integrated active and passive devices to serve a broad spectrum of applications.

For correct modeling of avalanche breakdown effects in bipolar transistors with the six transistor model, the multiplication factor M must be accurately described. However, as a simplification it is sometimes suggested to neglect its current dependence. We will show that this is not possible for advanced high-speed SiGe bipolar technologies. In this work, we present a practical model for M which takes the current into account as well. It allows simple parameter extraction and, moreover, can easily be used with standard circuit simulators. The model is verified for a fast pre-production SiGe technology by comparison to measurements.

Heterojunction bipolar transistors are often used for power amplifiers, e.g. in GSM phones. Such applications require very robust devices that are able to withstand large voltages and currents. For this, an adequately chosen collector doping profile is a key parameter. In this work, we present a technique for optimizing the collector doping profile with respect to transistor robustness. The applicability of our approach is demonstrated experimentally by measurements of InGaP/GaAs HBTs, showing a significant increase of the safe operating area due to collector profile optimization.