Nowadays, model-based development is a common method to deal with the complexity and wide rages of functionality in embedded systems. Especially in automotive domain MATLAB/Simulink is often used to develop controller software for embedded systems. However the usually used tools are originally not designed to model a product-line of embedded systems applications. Therefore there is a high complexity of the designed models. Additionally different tools are used for different design artefacts like requirements and implementation model. These tools are not connected to each other’s which causes inconsistencies. Different domains like electrical engineers, control engineers and computer scientist are involved in designing embedded systems. The different domains use different domain specific languages and have different requirements. This thesis introduces an approach considering requirements of different domains designing embedded systems. The main focus is the further model-based development of existing embedded applications, in particular the cooperation of control engineering and computer science. Both domains have partly different requirements. E. g. in computer science it is important to reuse software. However in control engineering there is a need for great flexibility in terms of external interface (actuators and sensors) and the according software parts since the actuators and sensor have critical influence on the performance of the controller. Hence both domains have conflicting requirements. In the second part of this thesis an approach on software product-line is adopted to the model-based development process. Model-based transformations and analysis are used to support the development. The transformations use all design artefacts to achieve consistent models with respect derived variants. The result of the analysis are views. This views are implemented using standardized transformations provided by a framework. Therefore new analysis views can be created combining and adopting these transformations.

In the above letter [1], it was assumed that the concomitant angular displacement of the laser beam is equal to the deviation angle of the MEMS mirror. However, according to the reflection law, the angular displacement of the reflected beam is twice the angle through which the mirror has rotated [2], see Fig. 1. Therefore, the field of view (FOV)—the sum of the maximum positive and negative deviat...

This work presents the design and the measured performance of a 8 Gb/s transimpedance amplifier (TIA) fabricated in a 90 nm CMOS technology. The introduced TIA uses an inverter input stage followed by two common-source stages with a 1.5 kΩ feedback resistor. The TIA is followed by a single-ended to differential converter stage, a differential amplifier and a 50 Ω differential output driver to provide an interface to the measurement setup. The optical receiver shows a measured optical sensitivity of −18.3 dBm for a bit error rate = 10−9. A gain control circuitry is integrated with the TIA to increase its input photo-current dynamic range (DR) to 32 dB. The TIA has an input photo-current range from 12 to 500 μA without overloading. The stability is guaranteed over the whole DR. The optical receiver achieves a transimpedance gain of 72 dBΩ and 6 GHz bandwidth with 0.3 pF total input capacitance for the photodiode and input PAD. The TIA occupies 0.0036 mm2 whereas the complete optical receiver occupies a chip area of 0.46 mm2. The power consumption of the TIA is only 12 mW from a 1.2 V single supply voltage. The complete chip dissipates 60 mW where a 1.6 V supply is used for the output stages.

An optical wireless communication system for an operation with wavelengths detectable by silicon optoelectronic integrated circuits is described. We use direct modulated vertical cavity surface emitting lasers as a transmitter. The field of view of the laser beam is adjusted with an adaptive optical system and aligned with a micro-electro-mechanical system based mirror for beam steering. To receive the modulated laser beam, we develop a receiver chip in 0.35 μm BiCMOS technology. The experimental system shows a 3 Gb/s wireless transmission over a distance of 7 m with a bit-error rate <;10-9 without cost intensive optical components and complex adjustment procedure.

This paper investigates a silicon (Si) avalanche double photodiode (ADPD) fabricated in 40-nm standard CMOS technology. Two different types of double photodiodes (DPDs) will be introduced. The first one is a P-well/deep-N-well/P-substrate(PW/DNW/P-substrate) DPD, and the second one is a P+/N-well/P-substrate (P+/NW/P-substrate) DPD. The basic structure of the proposed ADPD is formed by P+/NW and NW/P-substrate junctions in which the avalanche effect occurs at the P+/NW junction. The P+/NW/P-substrate ADPD demonstrates responsivity of 0.84 A/W and a 3-dB electrical bandwidth of 0.7 GHz at 850 nm. For 660 nm, the ADPD shows a responsivity of 0.49 A/W with an electrical bandwidth of 1.8 GHz. For 520 nm, a responsivity of 2.04 A/W and an electrical bandwidth of 1.4 GHz are achieved.

This work investigates two silicon (Si) photodiodes (PDs) fabricated in 40 nm standard CMOS technology. The basic structure of the proposed Si PD is formed by N+/P-substrate and N-well/P-substrate diodes. The N+/P-substrate PD demonstrates a responsivity of 0.09 A/W and an electrical bandwidth of 3 GHz for 8 V reverse bias at 520 nm. The N-well/P-substrate PD demonstrates a responsivity of 0.24A/W and an electrical bandwidth of 1.2 GHz for 14.8 V reverse bias at 660 nm. For 520 nm, the N-well/P-substrate PD shows a responsivity of 0.18A/W and an electrical bandwidth of 3.0 GHz for 14.8 V reverse bias.

The transient photocurrent response of a vertically stacked triple pn junction structure, which can detect three different colours simultaneously, is investigated. The triple pn junction structure is designed based on the effect that the penetration depth in silicon depends on light wavelength. To increase the bandwidth of optical sensor systems the transient photocurrent response is a critical parameter. The transient response is measured by applying three different light wavelengths to this triple junction structure. This triple pn junction structure is fabricated in a 0.6 mu m BiCMOS technology using a p(-)p(+) epitaxial wafer without any process modification. Based on the measurement results, it can be concluded that this triple pn junction structure can be applied to optical sensors without optical filters and the total data rate of this structure can reach up to 100 Mbit/s.

This paper presents a framework for model-based product lines of embedded systems. We show how to integrate model-based product line techniques into a consistent framework that can deal with large product lines as they are common in industry. The framework demonstrates the strengths of model-based techniques like abstraction, support for customised representations, and a high degree of automation. In particular, we provide the following contributions: (1) to shift existing product lines towards a model-based approach, we support the (semi-) automated extraction of models from existing requirement, test, and implementation artefacts; (2) to cope with the complexity of artefacts and their interrelations in industrial product lines, we support the generation of context-specific views. These views support developers, e.g., in analysing complex dependencies between different artefacts; (3) finally, we support automated product derivation based on an integrated hardware abstraction layer. Most of the presented concepts have been inspired by challenges arising in the industrial application of product line techniques in the model-based engineering of embedded systems. We report on experiences gathered during the application of the techniques to a prototypical product line (on a rapid prototyping platform in the university lab) and to industrial sample cases (at the industry partner).

We report and compare results obtained on Ge-on-Si photodetectors in lateral and vertical configurations. A bandwidth of 120GHz was obtained for the lateral photodetector. Both types shown operation up to 40 Gb/s. Keywords-Silicon photonics; germanium; photodetector; integrated optics.

A sensor system for the wavelength determination of LEDs is presented. The used sensor is a triple junction photodiode which needs no external filters. The sensor is implemented in a standard BiCMOS process without any process modifications. The sensor system is optimised for low analogue complexity and compatibility with mass production in a cost-sensitive environment. A proof of concept sensor system is presented which demonstrates the ability to determine the wavelength of LEDs. The measurements evaluate the linearity of the system and the possibility for a fast calibration in the production environment.

We report on lateral pin germanium photodetectors selectively grown at the end of silicon waveguides. A very high optical bandwidth, estimated up to 120GHz, was evidenced in 10 µm long Ge photodetectors using three kinds of experimental set-ups. In addition, a responsivity of 0.8 A/W at 1550 nm was measured. An open eye diagrams at 40Gb/s were demonstrated under zero-bias at a wavelength of 1.55 µm.

Software Product Lines (SPL) are an engineering technique to efficiently derive a set of similar products from a set of shared assets. In particular in conjunction with model-driven engineering. SPL engineering promises high productivity benefits. There is however, a lack of support for systematic management of SPL evolution, which is an important success factor as a product line often represents a long term investment. In this article, we present a model-driven approach for managing SPL evolution on feature level. To reduce complexity we use model fragments to cluster related elements. The relationships between these fragments are specified using feature model concepts itself leading to a specific kind of feature model called EvoFM. A configuration of EvoFM represents an evolution step and can be transformed to a concrete instance of the product line (i.e., a feature model for the corresponding point in time). Similarly, automatic transformations allow the derivation of an EvoFM from a given set of feature models. This enables retrospective analysis of historic evolution and serves as a starting point for introduction of EvoFM, e.g., to plan future evolution steps. (C) 2011 Elsevier Inc. All rights reserved.

A triple-junction photodetector for color detection is explored in the wavelength range from 400nm to 900nm. According to the mechanism that light with longer wavelength can penetrate silicon deeper than light with shorter wavelength the detector can detect different colors of incident light simultaneously and rather independently. We adopt three vertically stacked photodiodes in the detector, which accurately determine the color of the incident light. In addition, the photodetector can be used as wavelengths division demultiplexer for three different wavelengths in optical data receivers without needing beam splitters or optical filters. The detector is fabricated in a standard 90nm CMOS technology without any process modifications. Based on the measured results, we conclude that this kind of photodetector can meet the requirements of color detection and of data receivers up to150 Mbit/s.

A BiCMOS RGB color sensor for ambient light monitoring is presented. It can be used in applications like white balancing, color measurement and TFT monitor backlight control. The effect of different penetration depths in silicon for different wavelengths is used to determine the color of the incident light. The sensor is formed by three vertically stacked photodiodes — a shallow diode for blue, a middle diode for green and a deep diode for red light. The sensor is manufactured in standard BiCMOS technology using an epi-layer starting wafer. Thus this device can be easily integrated with RGB LED drivers or acquisition circuits into a single chip.

In dieser Arbeit wird ein filterloser, vertikaler, integrierter RGB-Farbsensor, hergestellt in einer 90-nm-CMOS-Technologie, vorgestellt. Der Sensor besteht aus drei vertikal übereinander liegenden pn-Übergängen und nutzt zur Bestimmung der Lichtfarbe die Tatsache, dass Licht unterschiedlicher Wellenlänge unterschiedlich tief in Silizium eindringt.

A filter-less BiCMOS RGB colour sensor for wavelength detection in the wavelength range from 400 to 900 nm is presented. The sensor is based on the effect that light with longer wavelength penetrates silicon deeper than light with shorter wavelength. The detector is formed by three vertically stacked photodiodes: a deep diode used as the sensing element for red light, a middle diode to detect green light and a shallow diode as the blue light detector. The resulting RGB output is used to accurately determine the wavelength of the incident light. The sensor is fabricated in standard 0.6 mu m BiCMOS technology without any process modifications.

An 8×10Gbps direct light-to-logic converter for hybrid mounted Ge photodiodes is presented. The receiver is realized in standard 0.35μm SiGe BiCMOS technology and the Ge photodetector is directly mounted on the top of the CMOS wafer. Each of the 8 channels includes a transimpedance amplifier, limiting amplifier stages and a 50Ω CML output driver. The overall transimpedance is 275kΩ and at a data rate of 10Gpbs a sensitivity of −23.1dBm (BER=10−9) is reached.

A high sensitivity 8×10 Gbps parallel integrated optical receiver with transimpedance amplifier followed by limiting amplifier stages and output driver in standard 0.35 μm SiGe BiCMOS technology with low input noise current (407 nA) is presented.

In embedded systems in general and in automotive systems in particular the systematic reuse of existing assets is crucial. Moreover, companies in these domains often offer whole families of similar products. Hence, the application of product line engineering seems to be an obvious option. However, current products have reached a complexity level where management of products within a product line cannot be handled with current techniques and tools (e.g. Matlab/Simulink) alone. To sustain an efficient engineering process and to reach the required quality levels of the products, additional techniques are required. In this paper we report on a prototypical framework for the analysis of embedded systems product lines. The techniques and tools offered by the framework were developed to support engineers in typical tasks, which occur during design, implementation, and maintenance of embedded software product lines. The techniques allow to analyse product line artefacts by transforming them into models, which are then used in an analysis process based on model transformation languages.