Here is the abstract you requested from the DPC_2009_Mems technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Tunable Millimeter-Wave Device Based on Waveguide-Packaged MEMS|
|Keywords: MEMS, millimeter-wave, power divider|
|Millimeter-wave front-ends realized in waveguide technology combine the advantage of low loss and the design freedom gained by use of the third dimension. For example, flat and compact waveguide array antennas have been proposed for 60 GHz. They are low-cost if made of metalized plastics. MEMS can be used for millimeter-wave circuits. Typically, they are implemented in planar transmission line integrated circuits. Switches and phase shifters have been proposed. However, in a waveguide-based front-end, the transitions from waveguide to planar circuit add significant loss. As a solution, it has been proposed to place a MEMS with upward-curling metal fingers directly inside a metal waveguide, realizing a switch: The upward-curling fingers short-circuit the waveguide, and when the fingers are flattened by electrostatic actuation, all power is transmitted . We propose to use another type of MEMS-activation: a metal-coated planar mirror of one square millimeters size, with single-axis rotation within +/-5 degrees. This device is activated by electrostatic comb actuators . The MEMS is placed in a three-dimensional T-junction waveguide structure (frequency 83 GHz), forming a power divider. By turning the MEMS mirror, power division of the millimeter-wave signal varies from 10:90% over 50:50% to 90:10%, keeping input reflection well below –15dB. The MEMS is placed in a cavity of a multilayer LTCC, the waveguide structure being glued on top. The simulated power loss in the structure is less than 15%. Phase balance (currently +/-15 degrees) needs further optimization. The proposed variable power divider can find use in antenna beam steering networks. Due to its low dissipative loss, placing a MEMS-activated, moveable metallic structure into a metal waveguide has other applications, such as tunable resonators and filters.  Daneshmand, Mansour; IEEE Transactions MTT, vol. 53 (2005), 3531.  Bachmann, Kuhne, Hierold; Proceedings MEMS 2007, 723.|