Filters

20183

More filters

20233
Reset filters

Settings

End date: 2018 × Start date: 2018 × DDC: 530 × WGL Institute: IHP ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    High-temperature high-sensitivity AlN-on-SOI Lamb wave resonant strain sensor
    (New York, NY : American Inst. of Physics, 2018) Dou, Shaoxu; Qi, Mengke; Chen, Cong; Zhou, Hong; Wang, Yong; Shang, Zhengguo; Yang, Jing; Wang, Dengpan; Mu, Xiaojing
    A piezoelectric AlN-on-SOI structured MEMS Lamb wave resonator (LWR) is presented for high-temperature strain measurement. The LWR has a composite membrane of a 1 μm thick AlN film and a 30 μm thick device silicon layer. The excited acoustic waves include Rayleigh wave and Lamb waves. A tensile strain sensor has been prepared with one LWR mounted on a uniaxial tensile plate, and its temperature characteristics from 15.4°C to 250°C and tensile strain behaviors from 0 μϵ to 400 μϵ of Rayleigh wave and S4 mode Lamb wave were tested. The temperature test verifies the adaptability of the tensile strain sensor to temperature up to 250°C, and S4 mode Lamb wave and Rayleigh wave represent almost the same temperature characteristics. The strain test demonstrates that S4 mode Lamb wave shows much higher strain sensitivity (-0.48 ppm/μϵ) than Rayleigh wave (0.05 ppm/μϵ) and confirms its advantage of strain sensitivity. Finally, for this one-LWR strain sensor, a method of beat frequency between S4 mode Lamb wave and Rayleigh wave is proposed for temperature compensation and high-sensitivity strain readout.
  • Thumbnail Image
    Item
    Dimensioning of a multibeam coherent photonic beamformer fed by a phased array antenna
    (Washington, DC : Optical Society of America, OSA, 2018) Drummond, Miguel V.; Duarte, Vanessa C.; Albuquerque, André; Nogueira, Rogério N.; Stampoulidis, Leontios; Winzer, Georg; Zimmermann, Lars; Clements, Stephen; Anzalchi, Javad
    The design and dimensioning of a photonic-aided payload for a multi-beam high-throughput communications satellite is a complex problem in which the antenna, RF and photonic subsystems must be considered as a whole for achieving best performance with lowest mass and power consumption. In this paper, we propose and dimension the receiving stage of a communications satellite comprising a phased array antenna (PAA) feeding a multibeam photonic beamforming system (PBS). The PBS uses a single wavelength and resorts to heterodyne detection such that the retrieved beams are frequency downconverted. End-to-end system modeling shows that the complexity of the PAA and PBS can be traded-o for signal-to-noise ratio (SNR) or power consumption without compromising the beam width. The dimensioning of a realistic scenario is presented, showing that an SNR and beam crosstalk on the order of 20 dB are achievable with a total power consumption below 1 kW for a typical number of 100 antenna elements (AEs).
  • Thumbnail Image
    Item
    High-performance SiGe HBTs for next generation BiCMOS technology
    (Bristol : IOP Publ., 2018) Rücker, Holger; Heinemann, Bernd
    This paper addresses fabrication aspects of SiGe heterojunction bipolar transistors which record high-speed performance. We previously reported fT values of 505 GHz, fMAX values of 720 GHz, and ring oscillator gate delays of 1.34 ps for these transistors. The impact of critical process steps on radio frequency performance is discussed. This includes millisecond annealing for enhanced dopant activation and optimization of the epitaxial growth process of the base layer. It is demonstrated that the use of a disilane precursor instead of silane can result in reduced base resistance and favorable device scalability.