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This paper reports on 1-chip RF-MEMS tunable capacitor that equips CMOS driver circuit in the underlying layer. A Wafer Level Chip Scale Package (WLCSP) optimized for RF-MEMS is employed to minimize the module size.The MEMS actuation voltage is generated by an Actuation Voltage Generator (AVG). The boost mechanism employed in the AVG enables instant high voltage generation and reduction of the dielectric charging. The measured noise at RF frequencies is less than -120dbm, thanks to a shield metal layer formed between MEMS and CMOS layers.To achieve high power handing and high creep immunity, we employ the previously reported techniques, the Quadruple Series Capacitor (QSC) [1] and the SiN springs [2]. The quality factor measured in the WLCSP is larger than 100 at 1GHz. The capacitance can be changed from 1.4pF to 5pF by a step of 0.45pF.

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In this paper, we report on a high-power handling RF-MEMS tunable capacitor that has a quadruple series capacitor (QSC) and a movable electrode using a slit with dielectric bridges (SDB) structure. The QSC structure consists of two fixed metal–insulator–metal (MIM) capacitors and two MEMS capacitor elements connected in series, and enables reduction of the RF voltage to the MEMS capacitors. The SDB structure is able to increase the release voltage without increasing the pull-in voltage. The combination of these structures enables improving power handling capabilities. A capacitor bank using QSC and SDB structures was fabricated by a micromachining process above CMOS control circuits. Measurement results demonstrate the excellent power handling capability up to +44 dBm for cold switching, and up to +35 dBm under hot switching. Moreover, the Q-factor of the capacitor bank is very high that is above 150 at 1 GHz, and the capacitance can be changed from 1.1 to 5.3 pF at a resolution of 4 bits by the internal control circuits thanks to monolithic integration.