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Valkama M.,Tampere University of Technology | Springer A.,Johannes Kepler University | Hueber G.,DICE GmbH
ISCAS 2010 - 2010 IEEE International Symposium on Circuits and Systems: Nano-Bio Circuit Fabrics and Systems

Building compact and low-cost yet flexible and reconfigurable radios for future wireless systems is generally a challenging task. On one hand, the needs for flexibility and re-configurability prevent using dedicated hardware particularly designed and optimized for only a single application or part of the radio spectrum. And on the other hand, to keep the overall size and cost of the radio equipment feasible, especially in multi-antenna multi-radio scenarios, the cost and size of individual radios are strongly limited. As a result, various imperfections and impairments are expected to take place in the used radio transceivers, especially in the radio frequency (RF) analog electronics. Good examples of such imperfections are, e.g., mirror-frequency interference due to I/Q imbalance, non-linear distortion due to mixer and amplifier nonlinearities, timing jitter and non-linearities in sampling and analog-to-digital (A/D) converter circuits, and oscillator phase noise. These impairments, if not properly understood and taken into account, can easily become a limiting factor to the quality and performance of the radio device and thereon of the whole wireless link. This is even more so, when more complex and more sensitive high-order modulated wideband communications waveforms are being deployed in the future systems. This article gives an overview of the essential RF impairments in modern radio communication context. Furthermore, different conceptual alternatives for reducing the effects of RF impairments in radio transmitters and receivers utilizing digital signal processing are described. ©2010 IEEE. Source

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ICT-2011.3.1 | Award Amount: 12.28M | Year: 2012

DOTSEVEN is a 3.5 year IP proposal for a very ambitious R&D project targeting the development of Silicon Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) technologies with cut-off frequencies (fmax) of around 700 GHz. Special attention will be paid to clearly demonstrate the capabilities and benefits of this technology with benchmark circuits and advanced system applications in the 0.1 to 1 THz range like THz imaging and sensing, wireless Gb/s communications and millimeter-wave radar.\nFor a given lithography node, HBTs provide much higher cut-off frequencies compared to CMOS transistors while offering higher power density and better analog performance. SiGe HBT technology and SiGe HBT enhanced CMOS (SiGe BiCMOS) are key enablers for demanding mm-wave systems requiring more than a few Watts of RF output power (which limits the applicability of even very advanced CMOS) and also offer high integration levels at low cost which precludes expensive and less integrated III-V solutions.\n10 out of the 12 DOTSEVEN participants were already partnering in the predecessor FP7 project DOTFIVE which succeeded for the first time to push fmax of SiGe HBTs (at room temperature) into the 500 GHz region thus setting a new world-wide benchmark. Triggered by the impressive DOTFIVE results, several activities in the rest of the world already have started to catch up or even surpass our achievements.\nThe main objective of the highly qualified and motivated DOTSEVEN consortium is therefore to significantly expand the successful work of DOTFIVE, to further strengthen Europes leading edge position in SiGe HBT technology and modeling as well as SiGe enabled mm-wave applications and to stay significantly ahead of non-European competition. A powerful and success-proven consortium has been set-up to achieve these goals. It consists of 5 industrial partners (including 3 SMEs) and 9 well distinguished academic research institutes spread all over Europe.

Fischer A.,Christian Doppler Laboratory | Tong Z.,Johannes Kepler University | Hamidipour A.,Johannes Kepler University | Maurer L.,DICE GmbH | And 2 more authors.
IEEE Transactions on Antennas and Propagation

This paper presents the design of a directional folded dipole antenna integrated in an embedded wafer level ball grid array (eWLB) package, the comparison of different antenna designs and the influence of the silicon die and neighboring antennas within the package to the radiation behavior. The co-integration of the antenna and the silicon-based monolithic microwave integrated circuit (MMIC) in a system in package (SiP) approach is a convenient solution to suppress lossy radio frequency (RF) transitions and to simplify the design and the manufacturing of radio frontends significantly. The proposed SiP is focused on 77-GHz automotive radar applications. The MMIC contains the 77-GHz signal source and a transceiver with amplifier and mixer. The gain of different antennas in different constellations within the package is shown. © 1963-2012 IEEE. Source

Fischer A.,Johannes Kepler University | Stelzer A.,Johannes Kepler University | Maurer L.,DICE GmbH
International Journal of Microwave and Wireless Technologies

A 77-GHz-directional folded dipole antenna integrated in an embedded wafer level ball grid array package is presented. For the characterization of the antenna, a frequency multiplier is embedded, which scales the 4.25-GHz input signal up to 76.5 GHz and allows the use of a commercial signal source. The antenna structure is manufactured at the metallic layer, in the fan-out area of the package, and is directly connected to the monolithically integrated transceiver. The gain of the antenna is about 7 dBi, measured over a large bandwidth of about 8 GHz. The combination of the frequency multiplier with a 77-GHz transceiver and the on-package antenna is a promising approach for a system-in-package to future radar modules for automotive radar applications. Such a module avoids 77-GHz transitions to the printed circuit board and hence simplifies the design and manufacturing of the radar sensor significantly. Copyright © 2012 Cambridge University Press and the European Microwave Association. Source

Topak E.,Sony | Hasch J.,Robert Bosch GmbH | Wagner C.,DICE GmbH | Zwick T.,Karlsruhe Institute of Technology
IEEE Transactions on Microwave Theory and Techniques

A novel beam-steering approach is presented based on the superposition of two squinted antenna beams. The two antenna beams are realized by exciting the opposite feeds of a dual-fed array antenna. A change in phase difference and amplitude ratio between the input signals, possibly using only one phase shifter and one variable gain amplifier, steers the main beam in different directions. Additionally, sum and difference patterns can be obtained using this concept, allowing for a monopulse operation with a broad peak or a deep null at broadside. Using this approach, beam nulls can also be steered toward interference directions, while keeping the shape and direction of the main beam unchanged. To verify the concept, a 77-GHz demonstrator using a linear patch array antenna and monolithic microwave integrated circuit in-phase/quadrature modulators has been designed and fabricated. The measurement results show a beam-scanning range of 16° , well in accord with the simulation results. © 1963-2012 IEEE. Source

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