One Single DMTL-based Circuit for RF-MEMS Impedance Tuners and Phase Shifters

Tatyana PURTOVA¹, Tauno VÄHÄ-HEIKKILIJ, Till FEGER¹, Thomas LISEC³, Joachim JANES³, Bernd WAGNER³, Hermann SCHUMACHER<sup>1

1</sup>University of Ulm, Department of Electron Devices and Circuits, Albert-Einstein-Allee 45,
Ulm, Germany
²MilliLab, VTT Technical Research Centre of Finland, Espoo 02044 VTT, Finland
³Fraunhofer Institute for Silicon Technology ISiT, Fraunhoferstraße 1, Itzehoe, Germany

Abstract. A DMTL-based circuit which can be used both as an impedance tuner and as a phase shifter is presented. It was optimized for the impedance tuner operation and impedance coverage with 256 states is achieved for 25-45 GHz (measured up to 50 GHz). Besides, a 3 bit phase shifter operation is possible, resulting in a phase shift of 180 deg at 35 GHz. This indicates a high potential for designing multi-purpose DMTL circuits. The circuit was fabricated at the Fraunhofer Institute for Silicon Technology ISiT (Itzehoe, Germany) using surfacemicromachining of high-resistivity silicon substrate.