Phase Error and Nonlinearity Investigation of Millimeter-Wave MEMS 7-Stage Dielectric-Block Phase Shifters
2009 (English)In: 2009 EUROPEAN MICROWAVE INTEGRATED CIRCUITS CONFERENCE (EUMIC 2009), NEW YORK: IEEE , 2009, 519-522 p.Conference paper (Refereed)
This paper reports on phase error and nonlinearity investigation of a novel binary-coded 7-stage millimeter-wave MEMS reconfigurable dielectric-block phase shifter with best performance optimized for 75-110-GHz W-band. The binary-coded 7-stage phase shifter is constructed on top of a 3D micromachined coplanar waveguide transmission line by placing lambda/2-long high-resistivity silicon dielectric blocks which can be displaced vertically by MEMS electrostatic actuators. The dielectric constant of each block is artificially tailor-made by etching a periodic pattern into the structure. Stages of 15, 300 and 45 are optimized for 75 GHz and put into a coded configuration of a 7-stage phase shifter to create a binary-coded 15 degrees+30 degrees+5x45 degrees 7-stage phase shifter with a total phase shift of 270 degrees in 19x15 degrees steps. The binary-coded phase shifter shows a return loss better than -17 dB and an insertion loss less than -3.5 dB at the nominal frequency of 75 GHz, and a return loss of -12 dB and insertion loss of -4 dB at 110 GHz. The measurement results also show that the binary-coded phase shifter performs a very linear phase shift from 10-110 GHz. The absolute phase error at 75 GHz from its nominal value has an average of 2.61 degrees at a standard deviation of 1.58 degrees for all possible combinations, and the maximum error is 6 degrees (for 240 degrees). For frequencies from 10-110 GHz, all possible combinations have a relative phase error of less than 3% of the maximum phase shift at the specific frequencies. The 7-stage binary-coded phase shifter performs 71.1 degrees/dB and 490.02 degrees/cm at 75 GHz, and 98.3 degrees/dB and 715.6 degrees/cm at 110 GHz. From the measured self-modulation behavior the third-order intermodulation (IM) products level are derived to -82.35 dBc at a total input power of 40 dBm with the third-order IM intercept point (IIP3) of 49.15 dBm, employing a mechanical spring constant of 40 N/m. In contrast to conventional MEMS phase shifters which employ thin metallic bridges which limit the current handling and show fatigue even at slightly elevated temperatures, this novel phase-shifter concept is only limited by the power handling of the transmission line itself, which is proven by temperature measurements at 40 dBm at 3 GHz and skin effect adapted extrapolation to 75 GHz by electro-thermal FEM analysis.
Place, publisher, year, edition, pages
NEW YORK: IEEE , 2009. 519-522 p.
IdentifiersURN: urn:nbn:se:kth:diva-13752ISI: 000276213900131ScopusID: 2-s2.0-72449166873ISBN: 978-1-4244-4749-7OAI: oai:DiVA.org:kth-13752DiVA: diva2:327259
4th European Microwave Integrated Circuits Conference Rome, ITALY, SEP 28-29, 2009
QC 20111215. Oral Presentation, Best Paper Award (EuMIC Prize)2010-06-282010-06-282011-12-15Bibliographically approved