Reconfigurable Three-Dimensional Micromachined Dielectric-Loaded CPW Phase-Shifter

N. SOMJIT, G. STEMME, J. OBERHAMMER

Royal Institute of Technology, Microsystem Technology, Osquldas väg 10, 10044, Stockholm, Sweden
E-mail: {nutapong.somjit, goran.stemme, joachim.oberhammer}@ee.kth.se

Abstract. In this paper three variations of wideband single-state digital microwave MEMS dielectric-loaded phase shifter based on 3dimensional micromachined coplanar waveguide (CPW) are introduced. By vertically moving a λ/2-long dielectric block above CPW with electrostatic actuation, relative phase shift between up and down state is determined. Periodically etched pattern of the dielectric block with three different sizes is introduced for tuning the effective dielectric constant resulting in relative phase shift of 45º, 30º and 15º. The devices are fabricated monolithically using an in-house bulk and surface micromachining process on a high-resistivity silicon substrate (HRSS). Measurement results show that the first prototype of this phase shifter has return and insertion loss better than -10 dB and -1.5 dB, respectively, for frequency range of 10 to 100 GHz with decent linear phase.