A new integration of device-scale micropackaging with bi-directional tunable capacitors

This paper demonstrates a novel and device-scale vacuum-sealed variable capacitor that allows a movale capacitive plate to be actuated in bi-direction for large capacitance tuning. Meanwhile, the micro cap is served as the packaging structure as well as top electrode which can protect the variable capacitor structure from undesired physical attack. By taking advantages of device-scale micro cap, the subsequent packaging procedures are able to utilize conventional I.C. packaging, minimizing changes due to an addition of integrated MEMS devices. Furthermore, the vacuum sealing can also be achieved to reduce phase noise and to alleviate the thermal, humid, and air damping effect. This approach is compatible with CMOS process and able to integrate micromachined variable capacitor and electric circuit into a single chip.