| A MEMS-based impedance tuner for use in a noise measurement system has been designed, prototyped and tested. A driver has also been designed in an integrated 0.8 mum technology. The overall goal is a tuner that is fabricable on top of the CMOS driver. This design is a proof-of-concept prototype on a printed circuit board.;The project utilizes serial phase-shift networks and switched capacitive loads. The phase-shift networks are Zobel networks with an input impedance matching the system characteristic-impedance. The switches used are third-party MEMS electrostatic switches.;Results show a useable range of impedances from 0.5 - 5 GHz. There were significant problems with the reliability of the MEMS switches, preventing testing in the noise measurement system. Ideas for a design revision are presented, perhaps one utilizing an alternative switching method. It would also be possible to attempt fabrication of a reduced-scale post-processed version. |
