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This paper presents our recent work towards state-of-the-art integrated test concepts for the in-situ characterization of silicon-integrated millimeter-wave devices and transceiver components for radar and communication applications. Narrowband as well as ultra-broadband integrated network analysis solutions for a variety of frequency bands ranging from 50 to 120 GHz are outlined. In this context,...
This paper proposes a permittivity sensitive phase-locked loop (PLL) for the characterization of biologically and medically relevant materials and liquids in a frequency frange from 19.2 GHz to 20.8 GHz. It utilizes a custom design voltage controlled oscillator (VCO) with a tank-integrated capacitive sensor fabricated on a SiGe process. A change of the permittivity opposed to the sensor leads to a...
In this paper a microwave permittivity sensing system based on a super-heterodyne reflectometer is presented. A set of two high directivity directional couplers is utilized for the derivation of a reference and a reflection measurement channel from a 14 –18 GHz stimulus. Integrated Gilbert-cell circuits were fabricated in a SiGe HBT technology and act as frequency converters for the high frequency...
This paper proposes an integrated reflectometer for biomedical sensor read-out applications using a low-cost silicon-germanium technology. The heterodyne reflectometer consists of two integrated cross-coupled oscillators, a set of two directional couplers as well as Gilbert-Cell downconversion mixers. A dual phase-locked-loop architecture guarantees the phase lock of both on-chip signal sources to...
This paper presents a wideband microwave approach towards biomedical dehydration monitoring. The introduced concept is verified via invasive measurements on several blood samples. A microwave measurement circuit, based of a two-port scalar vector network analyzer is presented. The circuit operates between 5GHz and 20GHz using a planar permittivity sensor. Measurements of all subcomponents are shown...
This paper presents a single-chip octave-bandwidth signal source covering a frequency band from 15GHz to 32GHz. The circuit was fabricated in a 0.35 µm SiGe bipolar technology with an ft/fmax = 170/250GHz. An array of four cross-coupled voltage controlled oscillators with subsequent frequency ranges is implemented. The oscillator cores only draw 13mA from a 3.3V supply. Another 13mA is drawn by following...
In this paper a complete procedure for the design, synthesis and construction of wideband directional couplers is presented. Cascading multiple quarter-wavelength line segments leads to an increase of coupling bandwidth up to 180% but also results in discontinuities of geometry and thus in strong reflections. Furthermore, the isolation is diminished. To avoid these effects a design technique for the...
The influence of non-perfect circularity of the left and right circular light waves of a reflective interferometric fiber-optic current sensor is theoretically and experimentally investigated for currents up to several 100 kA and temperatures from -40 to 80degC. By control of crucial parameters and appropriate packaging of the sensing fiber accuracy and repeatability within plusmn0.1% is achieved...
The nonlinearities in the response of an interferometric fiber-optic current sensor associated with inherent temperature compensation of the Faraday effect are investigated at currents up to several 100 kA and temperatures between -40 and 80degC.
A highly accurate fiber-optic current sensor for direct currents up to 500 kA is presented. Applications include the control of the electrolysis process for the production of metals such as aluminum, copper, zinc, magnesium, and others. The sensor offers significant advantages with regard to performance and ease of use compared to state-of-the-art Hall-effect-based current transducers. The sensor...
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