A differential 4-bit 6.5-10-GHz RF MEMS tunable filter

FREE-DOWNLOAD K Entesari… – Microwave Theory and Techniques, …, 2005 –
WIDE-BAND tunable filters are extensively used for multiband communication systems and wide-band tracking receivers. The most practical implementation is based on yttrium–iron–garnet (YIG) resonators. They have multioctave bandwidths and are high quality-factor resonators . However, they are bulky and cannot be easily miniaturized for wireless communications. They also consume considerable amount of dc powerand their linearity is not high An alternative to YIG filters is based on miniaturized planar filters with solid-state or microelectromechanical systems (MEMS) devices. Solid-state varactors can provide a wide tuning range, but they have loss and linearity problems at microwave frequencies . MEMS switches and varactors have very low loss, they do not consume any dc power, and their linearity is excellent