Title: Combined Time and Frequency Domain Wideband Characterisation of Submillimetre-Wave Active Transceivers
Abstract: The development of wideband analog transmit and receive frontends exploiting the high radio frequency bandwidths available in the high millimetre-wave and submillimetre-wave frequency bands requires instrumentation capable of accurate characterisation, both, in the time domain, where complex modulated signals are analysed in terms of their error vectors, and in the frequency domain, where vectorial network and spectrum analysis provides key performance indicators such as complex transfer functions and intermodulation products. A measurement setup capable of combined time and frequency domain characterisation of transceiver frontends in the WR-10, WR-6 and WR-3.4 waveguide frequency bands up to 325 GHz is presented. The in-situ combination of a wideband up-conversion channel with a directional coupler for the injection of a swept-frequency test signal for vectorial network analysis, combined with a vectorial spectrum analysis in the receive path, allows to characterise active transceivers and their functional components such as low-noise and power amplifiers by simultaneously applying test signals generated in the time and frequency domain. Techniques for measuring the third- and fifth-order intermodulation intercept points and the complex transfer functions of wideband submillimetre-wave transceivers in WR-3.4 are discussed. Digital pre-distortion of input signals in the RF bands allow for determining the degradation of the error-vector magnitude of transceiver components and amplifiers operating up to 325 GHz.
Biography:
Ingmar Kallfass received the Dipl.-Ing. degree in Electrical Engineering from University of Stuttgart in 2000, and the Dr.-Ing. degree from University of Ulm in 2005 on the topic of nonlinear modelling of dispersive heterostructure field effect transistors and their MMIC applications. In 2001, he worked as a visiting researcher at the National University of Ireland, Dublin. In 2002, he joined the department of Electron Devices and Circuits of University of Ulm as a teaching and research assistant. In 2005, he joined the Fraunhofer Institute for Applied Solid-State Physics. From 2009 to 2012, he was a professor at the Karlsruhe Institute of Technology. Since 2013, he holds the chair for Robust Power Semiconductor Systems at the University of Stuttgart, where his major fields of research are compound semiconductor-based circuits and systems for power and microwave electronics.
