Abstract: A semiconductor torsional micro-electromechanical (MEM) switch is described having a conductive movable control electrode; an insulated semiconductor torsion beam attached to the movable control electrode, the insulated torsion beam and the movable control electrode being parallel to each other; and a movable contact attached to the insulated torsion beam, wherein the combination of the insulated torsion beam and the control electrode is perpendicular to the movable contact. The torsional MEM switch is characterized by having its control electrodes substantially perpendicular to the switching electrodes. The MEM switch may also include multiple controls to activate the device to form a single-pole, single-throw switch or a multiple-pole, multiple-throw switch. The method of fabricating the torsional MEM switch is fully compatible with the CMOS manufacturing process.

Abstract: A high Q MEMS capacitor that can be continuously tuned with a large tuning ratio or reversibly trimmed using an electrostatic force. The tunable capacitor has a master/slave structure in which a control voltage is applied to the master (control) capacitor to set the capacitance of the slave (signal) capacitor to which an RF signal is applied via a suspended mechanical coupler. The master-slave structure reduces tuning error by reducing the signal capacitor's surface area and increasing its spring constant, and may eliminate the need for discrete blocking inductors by electrically isolating the control and signal capacitors. The trimmable capacitor provides an electrostatic actuator that selectively engages a stopper with teeth on a tunable capacitor structure to fix the trimmed capacitance.

Abstract: An apparatus for tuning a balanced-to-ground resonator, the resonator including at least one radio-frequency coil, the radio-frequency coil having an inductance forming a resonant circuit in combination with a capacitor, includes two identical differential capacitors which are mechanically coupled so that their respectively capacitances, during tuning, change in a balanced-to-ground fashion. In this tuning arrangement, the dependency of the frequency error on a change of the load of the resonator is negligibly small, so that a separate step or separate circuitry for undertaking frequency correction is not needed.

Abstract: A radio frequency tuner for ultra-high frequency range provided with an improved fine tuning device in which a conductor plate member is movably disposed in the vicinity of a resonant line whose one end is connected to a variable capacity element for tuning and whose other end is connected to earth directly or through a capacitor, so that the characteristic impedance of the distributed constant line is varied by driving the conductor plate member toward or away from the resonant line for fine adjustments of the tuned frequency.