A Novel Design on the Small Size and Low loss ۸-۱۲GHz RF-MEMS Tunable Filter

This paper presents a state-of-the-art RF microelectromechanical systems (MEMS) wide-band tunable filter in the ۸-۱۲GHz frequency range. The lumped LC filter, designed on a quartz glass substrate using high-Q suspended spiral inductors and MEMS variable capacitors, results in a tuning range of ۴۰% with excellent resolution, and return loss better than ۱۵dB for the whole tuning range. The fractional bandwidth of the ۱۶-filter responses is ۲.۵۵ ± ۰.۴۵% over the tuning range and the size of the filter is ۱.۷mm × ۰.۹mm. The insertion loss is ۰.۶۹dB and ۱.۰۳dB at ۱۰.۷۸۴GHz and ۸.۱۲۴GHz, respectively. The tuning speed of each variable capacitors are faster than ۱۸.۴μs and all three variable capacitors operate at the same time through one bias line by applying a voltage from ۱ to ۴۴V. To our knowledge, this is the smallest tunable filter with low loss in X-band range to date.

Keywords:

Lumped LC filter , microelectromechanical systems (MEMS) , RF MEMS , wide-band tunable filter , variable capacitor , low loss , X-band , fast tuning speed