The doctoral dissertations of the former Helsinki University of Technology (TKK) and Aalto University Schools of Technology (CHEM, ELEC, ENG, SCI) published in electronic format are available in the electronic publications archive of Aalto University - Aaltodoc.
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Studies on Microelectromechanically Tuneable High-Impedance Surface for Millimetre Wave Beam Steering

Dmitri Chicherin

Doctoral dissertation for the degree of Doctor of Science in Technology to be presented with due permission of the School of Electrical Engineering for public examination and debate in Auditorium S1 at the Aalto University School of Electrical Engineering (Espoo, Finland) on the 2nd of December 2011 at 12 noon.

Overview in PDF format (ISBN 978-952-60-4390-6)   [4524 KB]
Dissertation is also available in print (ISBN 978-952-60-4389-0)

Abstract

This thesis focuses on the development of novel microelectromechanically tuneable high-impedance surfaces (HIS) for millimetre wave beam steering applications. Microelectromechanical systems (MEMS) provide good functional parameters, e.g., low loss even at millimetre wave frequencies and excellent reliability, and can effectively compete with conventional technologies, e.g., ferroelectrics and ferrites. At the same time MEMS enable tuneability of the HIS, which can be used for developing reconfigurable devices with decreased system complexity, high level of integration and even as a system-on-a-chip, which dramatically reduces cost of the high frequency devices.

The proposed MEMS tuneable HIS consists of a two-dimensional periodical arrangement of MEMS varactors, with a period much smaller than the wavelength of the interacting electromagnetic field, placed on an electrically thin grounded dielectric substrate. Being embedded in a waveguide, the structure can be used as an analogue type phase shifting element controlled by a bias voltage connected to the MEMS varactors. Alternatively, the MEMS tuneable HIS can be used as a smart electronic beam steering reflective surface, if a reconfigurable gradient of the effective surface impedance is induced throughout the structure by applying different programmed bias voltages to the different rows of the MEMS varactors.

The methodology used in this study is a combination of analytical analysis, numerical simulations and electromagnetic measurements. A precise analytical model of the MEMS tuneable HIS is derived and used for designing of the structures operating in the W-band. Numerical simulations of different types of HIS and phase shifters based on the tuneable impedance surface embedded in rectangular metal waveguides and dielectric rod waveguides are carried out. Results of the numerical simulations correspond very well with the analytical calculations. Several prototypes of the multi-layered and MEMS-based HIS are fabricated and characterised. Measurements of the reflection coefficient show clear resonant high-impedance behaviour in the designed frequency range with reflection phase changing from almost 180° at lower frequencies to 0° at the resonance and to almost 180° at higher frequencies. The measured phase shifter based on a MEMS tuneable HIS placed adjacent to a dielectric rod waveguide exhibits an analogue type phase shift of up to 70° when the bias voltage is applied to the MEMS varactors.

This thesis consists of an overview and of the following 10 publications:

  1. D. Chicherin, S. Dudorov, D. Lioubtchenko, V. Ovchinnikov, S. Tretyakov, and A.V. Räisänen, MEMS-based high-impedance surfaces for millimeter and submillimeter wave applications, Microwave and Optical Technology Letters, vol. 48, no. 12, pp. 2570-2573, 2006.
  2. D. Chicherin, S. Dudorov, D. Lioubtchenko, V. Ovchinnikov, and A.V. Räisänen, Millimetre wave phase shifters based on a metal waveguide with a MEMS-based high-impedance surface, Proc. of the 36th European Microwave Conf., Manchester, UK, September 10-15, 2006, pp. 372-375.
  3. D. Chicherin, S. Dudorov, D. Lioubtchenko, V. Ovchinnikov, and A.V. Räisänen, Characterisation and measurements of a multilayer high-impedance surface at W-band, Proc. of the 1st International Congress on Advanced Electromagnetic Materials in Microwave and Optics, Rome, Italy, October 22-26, 2007, pp. 891-894.
  4. D. Chicherin, S. Dudorov, M. Sterner, J. Oberhammer, and A.V. Räisänen, Micro-fabricated high-impedance surface for millimeter wave beam steering applications, Proc. of the 33rd International Conf. on Infrared, Millimeter, and Terahertz Waves, Pasadena, California, USA, September 15-19, 2008, PID659522.pdf, Keynote presentation.
  5. M. Sterner, D. Chicherin, A.V. Räisänen, G. Stemme, and J. Oberhammer, RF MEMS high-impedance tuneable metamaterials for millimeter-wave beam steering, Proc. of the IEEE MEMS Conf., Sorrento, Italy, January 25-29, 2009, pp. 896-899.
  6. D. Chicherin, M. Sterner, J. Oberhammer, S. Dudorov, J. Åberg, and A.V. Räisänen, Analog type millimeter wave phase shifters based on MEMS tunable high-impedance surface in rectangular metal waveguide, IEEE International Microwave Symp. Digest, Anaheim, CA, USA, May 25-28, 2010, pp. 61-64.
  7. M. Sterner, D. Chicherin, J. Åberg, R. Sauleau, A.V. Räisänen, G. Stemme, and J. Oberhammer, Integration of microwave MEMS reconfigurable reflective surfaces in rectangular waveguide stubs, Proc. of Asia Pacific Microwave Conf., Yokohama, Japan, December 7-10, 2010, pp. 1825-1828.
  8. D. Chicherin, M. Sterner, J. Oberhammer, S. Dudorov, D. Lioubtchenko, A.J. Niskanen, V. Ovchinnikov, and A.V. Räisänen, MEMS based high-impedance surface for millimetre wave dielectric rod waveguide phase shifter, Proc. of the 40th European Microwave Conf., Paris, France, September 28-30, 2010, pp. 950-953.
  9. D. Chicherin, M. Sterner, D. Lioubtchenko, J. Oberhammer, and A.V. Räisänen, Analog-type millimeter-wave phase shifters based on MEMS tunable high-impedance surface and dielectric rod waveguide, International Journal of Microwave and Wireless Technologies, vol. 3, no. 5, pp. 533-538, 2011.
  10. Z. Du, D. Chicherin, and A.V. Räisänen, Millimeter wave beam steering with a MEMS-based high impedance surface, Proc. of European Microwave Conf., Manchester, UK, October 9-14, 2011, pp. 1043-1046.

Keywords: high-impedance surface, artificial electromagnetic materials, microelectromechanical systems, MEMS, beam steering, phase shifters, millimetre wave

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Last update 2012-01-03