A high power-handling RF MEMS tunable capacitor using quadruple series capacitor structure

Yamazaki, Hiroto; Ikehashi, Tamio; Saito, Tomohiro; Ogawa, Etsuji; Masunaga, Takayuki; Ohguro, T.; Sugizaki, Yoshiaki; Shibata, H.

doi:10.1109/mwsym.2010.5518281

Cited by 8 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The four capacitor elements are series connected between port1 and port2. This structure enables high power handing as reported previously [1]. The gap between the top and bottom electrode is 2.5um.…”

Section: High Power-handling Rf-mems Structurementioning

confidence: 72%

“…To explain this, let us denote the upstate and downstate MEMS capacitance as C MEMS_UP , C MEMS_DOWN and parasitic capacitance of the top electrode node as C para . Then V act is written as (1) As soon as the MEMS actuator goes down, the MEMS capacitance increases from C MEMS_UP to C MEMS_DOWN . This implies that the actuation voltage will be reduced automatically in the downstate, since the charge amount of the top electrode is conserved during the transition.…”

Section: Driver Circuitmentioning

confidence: 99%

See 1 more Smart Citation

A CMOS embedded RF-MEMS tunable capacitor for multi-band/multi-mode smartphones

Kurui

Yamazaki

Shimooka

et al. 2012

2012 IEEE 62nd Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: High Power-handling Rf-mems Structurementioning

confidence: 72%

Section: Driver Circuitmentioning

confidence: 99%

A CMOS embedded RF-MEMS tunable capacitor for multi-band/multi-mode smartphones

Kurui

Yamazaki

Shimooka

et al. 2012

2012 IEEE 62nd Electronic Components and Technology Conference

Self Cite

View full text Add to dashboard Cite

show abstract

“…2.1 Quadruple series capacitor structure Figure 1 shows the top view, cross-sectional view, and equivalent circuit of our tunable capacitor. 29) The tunable capacitor consists of two MEMS capacitor elements (C MEMS ) and two fixed metal-insulator-metal (MIM) capacitors (C MIM ). The MEMS capacitor is actuated by electrostatic force.…”

Section: Conceptmentioning

confidence: 99%

CMOS-embedded high-power handling RF-MEMS tunable capacitor using quadruple series capacitor and slit with dielectric bridges structure

Yamazaki

Kurui

Saito

et al. 2018

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

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.

show abstract

“…Next we explain a creep-immune RF-MEMS tunable capacitor with quadruple series capacitors (QSC) structure [7]. The photo and schematic cross-section of the capacitor unit are shown in Figs.4 and 5, respectively.…”

Section: Rf-mems Tunable Capacitormentioning

confidence: 99%

A long-term reliability analysis of a creep-immune RF-MEMS tunable capacitor

Ogawa

Masunishi

Ikehashi

et al. 2011

2011 16th International Solid-State Sensors, Actuators and Microsystems Conference

View full text Add to dashboard Cite

Actuators used in RF-MEMS tunable capacitors have an issue of creep-induced deformation. The creep is caused by a ductile-metal beam which is indispensable to attain the low loss. To avoid this issue, we previously reported an actuator structure that uses a brittle material, silicon nitride (SiN), at the stress-concentrated spring portions [1]. The present paper aims to clarify a long-term creep immunity of the actuator. We first determined parameters of Norton's law by measurements and then carried out Finite Element Method (FEM) simulations. As a result, we found that the shift of the up-state capacitance is 2.2% after keeping the actuator in down-state position for 3 years at 85 o C.

show abstract

A high power-handling RF MEMS tunable capacitor using quadruple series capacitor structure

Cited by 8 publications

References 5 publications

A CMOS embedded RF-MEMS tunable capacitor for multi-band/multi-mode smartphones

A CMOS embedded RF-MEMS tunable capacitor for multi-band/multi-mode smartphones

CMOS-embedded high-power handling RF-MEMS tunable capacitor using quadruple series capacitor and slit with dielectric bridges structure

A long-term reliability analysis of a creep-immune RF-MEMS tunable capacitor

Contact Info

Product

Resources

About