Fully integrated micromachined capacitive switches for RF applications

Park, J.Y.; Kim, G.H.; Chung, Ki-Woong; Bu, Jong Uk

doi:10.1109/mwsym.2000.860979

Cited by 28 publications

(32 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: A) Classificationmentioning

confidence: 99%

“…In the figure, the selected dark squares represent the desired performances of a switch. The fabricated capacitive switch is in general more compact and achieves higher isolation than their counterpart MEMS switches [1][2][3][4][5][6], for similar actuation voltages ( Fig. 3(a)).…”

Section: B) State Of the Artmentioning

confidence: 99%

“…Analog MEMS capacitors can be used for signal routing purposes, in reconfigurable front-ends, digitized capacitor banks, and reconfigurable antenna orientation or apertures. In order to achieve high isolation, many different configurations have been reported based on shunt and series switches [1][2][3][4][5][6][7][8], low spring constant anchoring [3], inductive behavior [8], and/or using high dielectric constant materials [4,6,7].On the other hand, the digital MEMS capacitor is generally used as part of tunable systems or reconfigurable networks, for example filters, phase shifters, or impedance matching with two known capacitive states. The concept of the digital capacitor was first introduced by Hayden and Rebeiz [9] and is defined as the standard MEMS capacitive switch in series with a fixed small capacitance possibly realized with metalinsulator-metal (MIM) capacitor [10], metal-air-metal (MAM) capacitor [11], or interdigitated capacitors.…”

mentioning

confidence: 99%

See 2 more Smart Citations

RF-MEMS switches with AlN dielectric and their applications

Badia

Nicole²,

Ionescu

2011

Int. J. Microw. Wireless Technol.

View full text Add to dashboard Cite

This paper reports on the potential of RF-MEMS technology based on aluminum nitride capacitive dielectric and nickelsuspended membranes to provide RF circuit functions in reconfigurable front-end radios. The RF performance of capacitive switches, distributed MEMS transmission lines (DMTLs) phase shifters for beam steering and tunable filters, including center frequency and bandwidth tuning of bandpass and band-stop filters are presented. Detailed characterization based on S-parameter data demonstrates very promising figures of merit of all fabricated demonstrators from 5 to 40 GHz.Keywords: RF MEMS switch, phase shifter, tunable filter, modelling, simulation and characterization of devices and systems I . I N T R O D U C T I O NIn the last half-century, RF-MEMS switches have been extensively studied as they accomplish superior RF performance and higher linearity than semiconductor junction switches such as Positive-Intrinsic-Negative (PIN) diodes or Fieldeffect transistor (FETs) [1]. Despite their higher control voltages compared to some solid-state switches, electrostatic-actuated Micro-electro-mechanical-systems (MEMS) offer significant power savings as well as potential lower cost and the capability of miniaturization which result in attractiveness for their use in wireless applications.In reconfigurable front-end RF ICs, functions like RF switching, filtering, and phase shifting in reflector array antennas for beam steering/forming networks (as illustrated in Fig. 1), can be realized with RF-MEMS components and systems using the same technology in a single fabrication process. RF MEMS offer new possibilities for improved performance and allow higher density and capacity of the overall systems.In this paper we present capacitive shunt switches in terms of performance as well as their applications as phase shifters and tunable filters. In Section II, the state of the art of capacitive switches is studied and compared with different fabricated switch designs including those based on analog and digital capacitor concepts and switches with highly inductive components that were specifically designed as core devices for the applications presented in the subsequent sections. Then, in Section III analog and 2-bit digital true time delay (TTD) phase shifters are described as well as the co-integration of phase shifters and the dipole antennas for beam steering applications. Finally, tunable filters with different functionalities, as bandpass and band-stop filter configurations are shown in Section IV. I I . R F -M E M S C A P A C I T I V E S W I T C H › S W I T C H I N G A) ClassificationCapacitive switches are mainly divided into two subcategories depending on their different functionalities; the RF-MEMS capacitive switch or analog MEMS capacitor, with high isolation and an increased capacitance ratio, Cr (.30) and the MEMS switch capacitor or digital MEMS capacitor with a moderate and usually defined Cr , 5. Analog MEMS capacitors can be used for signal routing purposes, in reconfigurable front-ends, digitized capa...

show abstract

Section: A) Classificationmentioning

confidence: 99%

Section: B) State Of the Artmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

RF-MEMS switches with AlN dielectric and their applications

Badia

Nicole²,

Ionescu

2011

Int. J. Microw. Wireless Technol.

View full text Add to dashboard Cite

show abstract

“…In phased array antennas, RF signal routing in phase shifter is implemented by a sequence of RF switches. The spectacular performance of RF MEMS switch in comparison to that of the more conventional PIN diodes and GaAs FET regarding insertion loss and isolation, return loss in both up (off) and down (on) status and extremely low standby power dissipation have made the use of RF MEMS switch common and attractive in RF wireless applications 58 The integration of MEMS switch with electronics involves the use of coplanar waveguids on silicon/GaAs substrate, aluminium or gold membranes and actuation voltage ranging from 30-110 V requesting a dedicated dc. current for the purpose.…”

Section: Rf Mems Switchesmentioning

confidence: 99%

Complementary Metal Oxide Semiconductors Microelectromechanical Systems Integration

Saha¹,

Chaudhuri²

2009

DSJ

View full text Add to dashboard Cite

A review of the integration of the complementry metal oxide semiconductors (CMOS) circuit with the microelectromechanical systems (MEMS) structures for sensing and RF applications has been presented. Specifically, the integrated mechanical sensors, chemical gas sensors, and biochemical sensors have been discussed. Application of MEMS as switches, varactors, and inductors and their integration in RF circuits has also been highlighted. The fabrication and design challenges for the CMOS-MEMS integration have been described. A new design methodology for integration of thermal effects in an integrated pressure sensor has been proposed.

show abstract

“…SiO 2 and Si 3 N 4 are still the most-commonly used insulator materials because of their technology maturity. Switches of SiO 2 and Si 3 N 4 have limited isolation performance due to their low dielectric constant. As a result, much of recent effort has been devoted to seeking new high-k dielectrics.…”

mentioning

confidence: 99%

High-k Dielectrics for Application in Broadband Radio Frequency-Microelectromechanical System Capacitive Shunt Switch

Zhang

Ichiki

et al. 2007

IEEJ Trans. SM

View full text Add to dashboard Cite

The performance of RF MEMS capacitive shunt switch is dominantly determined by the insulator layer. Thin high-k dielectric is preferred for achieving high down-state capacitance, which in particularly determines the switch performance at low frequency range. It is also well known that the reliability of RF capacitive switches is mainly determined by the charging of the insulator layer if package is hermetic and near-hermetic. SiO 2 and Si 3 N 4 are still the most-commonly used insulator materials because of their technology maturity. Switches of SiO 2 and Si 3 N 4 have limited isolation performance due to their low dielectric constant. As a result, much of recent effort has been devoted to seeking new high-k dielectrics. SrTiO 3 (k = ~ 200), Ta 2 O 5 (k = ~ 22), and (Ba, Sr)TiO 3 (k= ~ 29) dielectric have been investigated. It is worthy to note that HfO 2 -based dielectrics, which are leading candidate materials for next generation of high-k gate dielectric, have been being ignored in RF MEMS capacitive switch. High isolation performance had been achieved for RF MEMS capacitive switch using 250 nm-thick PZT/100 nm-thick HfO 2 stack dielectric in our previous work. It would be interesting to examine application of single HfO 2 dielectric layer in RF-MEMS capacitive switch. In this work, π-type RF-MEMS capacitive shunt switches of PZT/HfO 2 stack and single HfO 2 dielectric would be developed and characterized for broadband application. Figure 1 illustrates schematic structure of the π-type RF-MEMS capacitive shunt switch, which was fabricated using 5 masks in this work. The insulator layer is 100 µm square.Polycrystalline PZT layer in 130 nm thick was achieved after annealing at 500 o C using the sol-gel procedure. HfO 2 dielectric was prepared by sputtering. The PZT film had the dielectric constant of about 1185 at 1k Hz and the remanent polarization Pr of 9.86µC/cm 2 . The HfO 2 had the dielectric constant of about 17and the dielectric strength of about 24 MV/cm. Figure 2 shows the measured RF performance of the prepared RF MEMS switches. All the prepared switches had insertion loss better than -0.75 dB in the whole measured frequency range (1~35 GHz). The switches exhibited excellent isolation performance in a broadband range (1~35 GHz). The switch of HfO 2 has the isolation performance better than -40 dB in the sweep frequency range of 5 ~ 35 GHz. The PZT/HfO 2 stack dielectric-based switch had the isolation better than -20 dB within the whole sweep frequency range. The PZT layer had complicated effects. 130 nm-thick lead zirconate titanate(PZT)/45 nm-thick HfO 2 stack and single 45 nm-thick HfO 2 dielectric film were utilized as insulator layer in π-type radio frequency (RF) capacitive shunt switches for achieving high isolation performance in broadband application. Thin PZT film in perovskite structure mainly with (1 1 1) orientation was successfully prepared at low temperature (500 o C) using sol-gel method. The thin PZT film exhibited excellent ferroelectric properties and high dielectric constant (k ≈ 1...

show abstract

Fully integrated micromachined capacitive switches for RF applications

Cited by 28 publications

References 6 publications

RF-MEMS switches with AlN dielectric and their applications

RF-MEMS switches with AlN dielectric and their applications

Complementary Metal Oxide Semiconductors Microelectromechanical Systems Integration

High-k Dielectrics for Application in Broadband Radio Frequency-Microelectromechanical System Capacitive Shunt Switch

Contact Info

Product

Resources

About