Microwave measurements

Who are we?logo MMG_export_stroke_big_0.png

We are a research group engaged in the microwave measurement, design and construct of high-frequency circuits and systems. Our work covers a wide spectrum of the microwave domain from the theory of the calibration-correction methods to complex designs and large microwave measurement systems.

Karel Hoffmannkarel_0.jpg

  • He is leader of the “Microwave measurements” group.
  • On the department of electromagnetic field he is coordinating work related with microwave measurement and with design of planar microwave devices. His main research is focused on design of active and passive microwave integrated circuits, precise microwave measurement and modelling of electromagnetic components.

Přemysl Hudecpremek_0.jpg

  • Among his main interests belongs design of systems for active radar defense of vehicles and buildings, precise microwave measurements and design of integrated circuits and systems.
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Zbyněk Škvorzbynek_0.jpg

  • His main activities include the design of active and passive microwave integrated circuits, precision microwave measurement and modeling of microwave components.
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Viktor Adleradler_gs.jpg

  • He is a graduate student at the department of electromagnetic field.
  • Among his main interests belongs microwave interferometic measurements, evaluation of uncertainties and design of microwave circuits and systems.

Martin Haase

  • He is a graduate student at the department of electromagnetic field.
  • His main research is focused on the measurement of extreme impedances, which covers simulations of complex structures in electromagnetic simulators like CST and HFSS. Among his further activities belongs the design of active and passive microwave circuits. He is also interested in precise microwave measurement, numerical methods for electromagnetic field (e.g. FEM) and evaluation of uncertainties.

Vojtěch Jeníkjenik_0.jpg

  • He is a graduate student at the department of electromagnetic field.
  • Among his main interests belongs design of systems for active radar defense of vehicles and buildings, precise microwave measurements and design of integrated circuits and systems.

Filip Kozákkozak_gs_0.jpg

  • He is a graduate student at the department of electromagnetic field.
  • His main interest is the simulation of the electromagnetic field. Other interest include design and construct active radar system for protection of vehicles.

Ondřej Morávekmoravek_1.jpg

  • He is a graduate student at the department of electromagnetic field.
  • His main research focus is modelling complex planar structures in CST and HFSS. Among his interests are design of active and passive microwave components and precise microwave measurements.

Milan Příhodaprihoda_0.jpg

  • He is a graduate student at the department of electromagnetic field.
  • His main interest is the microwave interferometry and interferometric measurements. Other interests include design of active and passive microwave components.

Research directions

We are interested into research and application in the microwave frequencies. We are also developing microwave systems for wide range of purposes. Our goal is competitive research in the high frequency area and development of modern measurement techniques. We are also focused into the computer simulations of microwave structures and circuits in advanced 3D electromagnetic field simulators (CST Microwave Studio and ANSOFT HFSS) and application of the obtained results in the development of microwave circuits or another precise components for measurement. We are also interested into active radar defence of buildings and vehicles.

Pictures of some practical realizations

Design of active and passive microwave circuits and components

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The results of cooperation with external workplaces

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Equipment of measuring workplaces

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Simulation of microwave structures in advanced 3D electromagnetics field simulators.

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What is it good for?

Results of our work impact design of novel or improved measurement methods, integrated circuits or whole measurement systems in the microwave frequency range. Research in the area of measurement technique finds application in characterization of modern transistors, devices and materials in the high frequencies range. Together with development and improvement of measurement methods we also aim to design novel types of active and passive high-frequency circuits. Our work is applicable in industry and not only in the high frequency components but also for precise measurement of distances or thicknesses. Our cooperation with industry includes development of active protection of vehicles and buildings against ballistic missiles.

What are we working on?

  • Measurement of extreme impedances (In microwave range using VNA)
  • Precise measurement of thickness and distance
  • Precise vector measurement in open (planar) structures
  • Microwave interferometric measurements
  • System for active radar defense of buildings and vehicles
  • Modeling and electromagnetic simulations of transistor packages
  • Multimode planar structures
  • Calibration and corrections methods for microwave measurement

Sponsors of our research

  • MSM6840770015 - Výzkum metod a systémů pro měření fyzikálních veličin a zpracování naměřených dat (2005-2011, MSM)

Our partners

Selected publications

  • [1] Hoffmann,K., Sokol,V.; Škvor,Z.; “Arbitrary Q-Factor Dielectric Resonator”, Radioengineering, December 2001, vol. 10, no. 4, pp. 21-23. (pdf)
  • [2] Hoffmann,K., Vajtr,J.; “Solenoid above Ground Plane - Equivalent Circuit”, Radioengineering, December 2001, vol. 10, no. 4, pp. 17-20. (pdf)
  • [3] Sokol,V., Hoffmann,K., Vajtr,J.; “Noise Figure Measurement of Highly Mismatched DUT”, Radioengineering, September 2003, vol. 12, no. 3, pp. 13-15. (pdf)
  • [4] Sokol,V., Černý,P., Hoffmann,K., Škvor,Z.; “Assembly Influence on the Small-Signal Parameters of a Packaged Transistor”, Radioengineering, December 2005, vol. 14, no. 4, pp. 75-80. (pdf)
  • [5] Závodný,V., Hoffmann,K., Škvor,Z.; “Seven State PTP for Vector Network Analyzer”, Radioengineering, December 2005, vol. 14, no. 4, pp. 87-90. (pdf)
  • [6] Hudec,P., Polívka,M., Pechač,P.; “Microwave System for the Detection and Localization of Mobile Phones in Large Buildings”, Microwave Theory and Techniques, IEEE Transactions on, vol.53, no.6, pp. 2235- 2239, June 2005. (IEEEXplore)
  • [7] Zela,J., Hoffmann,K., Hudec,P.; “Errors in Measurement of Microwave Interferograms Using Antenna Matrix”, Radioengineering, Semptember 2008, vol. 17, no. 3, pp. 25-32. (pdf)
  • [8] Polívka,M., Švanda,M., Hudec,P., Zvánovec,S.; “UHF RF Identification of People in Indoor and Open Areas”, Microwave Theory and Techniques, IEEE Transactions on, vol.57, no.5, pp. 1341-1347, May 2009. (IEEEXplore)
  • [9] Randus,M., Hoffmann,K.; “A Method for Direct Impedance Measurement in Microwave and Millimeter-Wave Bands”, Microwave Theory and Techniques, IEEE Transactions on, vol.59, no.8, pp. 2123-2130, Aug. 2011. (IEEEXplore)
  • [10] Randus,M., Hoffmann,K.; “Microwave Impedance Measurement for Nanoelectronics”, Radioengineering, March 2011, vol. 20, no. 1, pp. 276-283. (pdf)
  • [11] Morávek,O., Hoffmann,K.; “Improvement to Load-pull Technique for Design of Large-signal Amplifier in K Band”, Radioengineering, December 2011, vol. 20, no. 4, pp. 828-831. (pdf)
  • [12] Morávek,O.; Hoffmann,K.; “Measurement and Simulation of Coaxial to Microstrip Tansitions' Radiation Properties and Sbstrate Influence”, Radioengineering, June 2012, vol. 21, no. 2, p. 568-572. (pdf)
  • [13] Morávek,O.; Hoffmann,K., “Radiation properties of Coaxial-to-coplanar transitions in K band”, In: Electronics Letters. 2012, vol. 48, no. 16, p. 1003-1004. (IEEEXplore)
  • [14] Příhoda, M.; Hoffmann, K., "Novel Multimode Planar Absorbing Structure," IEEE Microwave and Wireless Components Letters. 2013, vol. 23, no. 1, p. 7-9. ISSN 1531-1309. (IEEEXplore)
  • [15] Příhoda, M.; Hoffmann, K., "Self-calibrating evaluation method for microwave interferometry measurements," Electronics Letters. 2013, vol. 49, no. 49(5), p. 356-358. ISSN 0013-5194. (IEEEXplore)
  • [16] Moravek, O.; Hoffmann, K.; Polivka, M.; Jelinek, L., "Precise Measurement Using Coaxial-to-Microstrip Transition Through Radiation Suppression," Microwave Theory and Techniques, IEEE Transactions on , vol. PP, no. 99, pp. 1,10. (IEEEXplore)