Title :
Laterally driven tunable capacitors fabricated by a surface micromachining process for RF circuits
Author_Institution :
Coll. of Electron. & Inf. Eng., Nanjing Univ. of Inf. Sci. & Technol., Nanjing, China
Abstract :
A laterally driven micro machined tunable capacitor is proposed. As an alternative to the traditional designs using two electrodes, three electrodes are used so that the series resistance could be reduced. This design also offers opportunities in the circuit design, since the DC-bias voltage is not applied on the two ports. To achieve the capacitance on the order of 0.4 pF, the electrodes are periodically arranged to form three groups of arrays. Thermal actuator arrays are employed to drive the movable electrodes. In order to simplify the design and fabrication, a structure using two layers to build the electrodes is provided, where the capacitance varies from 0.05 pF to 0.13 pF. This two-layer capacitor has been fabricated using a polysilicon surface micro machining process potentially compatible with CMOS process.
Keywords :
CMOS integrated circuits; actuators; capacitors; electrodes; integrated circuit design; micromachining; radiofrequency integrated circuits; CMOS process; DC-bias voltage; RF circuits; circuit design; laterally driven micro machined tunable capacitor; laterally driven tunable capacitors; movable electrodes; polysilicon surface micromachining process; series resistance; thermal actuator arrays; CMOS process; Electrodes; Micromachining; Microwave FET integrated circuits; Microwave integrated circuits; Microwave measurements; Microwave theory and techniques; MEMS; RF circuit; microactuator; microfabrication; tunable capacitor;
Conference_Titel :
Circuits,Communications and System (PACCS), 2010 Second Pacific-Asia Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-7969-6
DOI :
10.1109/PACCS.2010.5626961