Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Waveguide-Integrated MEMS Concepts for Tunable Millimeter-Wave Systems
KTH, School of Electrical Engineering (EES), Micro and Nanosystems. (RF MEMS)
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis presents two families of novel waveguide-integrated components based on millimeter-wave microelectromechanical systems (MEMS) for reconfigurable systems. The first group comprises V-band (50–75 GHz) and W-band (75–110 GHz) waveguide switches and switchable irises, and their application as switchable cavity resonators, and tunable bandpass filters implemented by integration of novel MEMS-reconfigurable surfaces into a rectangular waveguide. The second category comprises MEMS-based reconfigurable finlines integrated as phase shifters into a rectangular waveguide array to demonstrate beams steering with a phased array antenna.

The first group of the presented reconfigurable waveguide components is based on a novel MEMS-reconfigurable surface structured in the device layer of a silicon-on-insulator (SOI) wafer using metallized mono-crystalline silicon as structural and functional material. The chip containing the reconfigurable surface is integrated in the cross-section of a WR-12 rectangular waveguide perpendicular to the wave propagation. The reconfigurable surface is modified for different states by on-chip push-pull electrostatic comb-drive MEMS actuators. The switch is ON when the reconfigurable surface is in its transmissive state and OFF when the reconfigurable surface is in its blocking state for the propagating wave. This millimeter-wave waveguide switch shows an insertion loss and isolation very similar to high-performance but bulky mechanical rotary waveguide switches, despite being extremely compact (30 μm thick), and thus combines the high electrical performance of mechanical switches with the size of (high power consuming and inferior performance) PIN-diode waveguide switches. This thesis also investigates the optimization to decrease the number of contact points for the OFF state and presents a device yield analysis. The same concept is developed further to MEMS-switchable inductive and capacitive irises, with the performance similar to ideal irises. With such MEMS-reconfigurable irises a switchable cavity resonator was implemented and the potential of tunable bandpass filters are demonstrated. Since these devices feature all-metal design as no dielectric layers are utilized, no dielectric charging effect is observed. Furthermore, this thesis investigates the low-loss integration of millimeter-wave MEMS-reconfigurable devices into rectangular waveguide with conductive polymer interposers.

The second group of components comprises finlines which are fabricated out of two bonded silicon wafers with bilateral gold structures integrated into a WR-12 rectangular waveguide. A 2-bit waveguide phase shifter is designed for 77-GHz automotive radar. Such phase shifters are used as individual building blocks of a two-dimensional antenna array for beam steering frontends.

Place, publisher, year, edition, pages
KTH Royal Institute of Technology, 2014. , xv, 85 p.
Series
TRITA-EE, ISSN 1653-5146 ; 2014:012
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-143040ISBN: 978-91-7595-062-4 (print)OAI: oai:DiVA.org:kth-143040DiVA: diva2:705226
Public defence
2014-04-04, F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20140317

Available from: 2014-03-17 Created: 2014-03-14 Last updated: 2014-03-17Bibliographically approved
List of papers
1. MEMS reconfigurable millimeter-wave surface for V-band rectangular-waveguide switch
Open this publication in new window or tab >>MEMS reconfigurable millimeter-wave surface for V-band rectangular-waveguide switch
Show others...
2013 (English)In: International Journal of Microwave and Wireless Technologies, ISSN 1759-0787, Vol. 5, no 3, 341-349 p.Article in journal (Refereed) Published
Abstract [en]

This paper presents for the first time a novel concept of a microelectromechanical systems (MEMS) waveguide switch based on a reconfigurable surface, whose working principle is to block the wave propagation by short-circuiting the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. The reconfigurable surface is only 30 mu m thick and consists of up to 1260 micro-machined cantilevers and 660 contact points in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. Measurements of fabricated prototypes show that the devices are blocking wave propagation in the OFF-state with over 30 dB isolation for all designs, and allow for transmission of less than 0.65 dB insertion loss for the best design in the ON-state for 60-70 GHz. Furthermore, the paper investigates the integration of such microchips into WR-12 waveguides, which is facilitated by tailor-made waveguide flanges and compliant, conductive-polymer interposer sheets. It is demonstrated by reference measurements where the measured insertion loss of the switches is mainly attributed to the chip-to-waveguide assembly. For the first prototypes of this novel MEMS microwave device concept, the comb-drive actuators did not function properly due to poor fabrication yield. Therefore, for measuring the OFF-state, the devices were fixated mechanically.

Keyword
RF-MEMS and MOEMS, Passive components and circuits
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-117932 (URN)10.1017/S1759078713000378 (DOI)000321588500018 ()2-s2.0-84880249868 (Scopus ID)
Funder
EU, European Research Council, 267528
Note

QC 20130814

Available from: 2013-02-07 Created: 2013-02-07 Last updated: 2014-03-28Bibliographically approved
2. Integration of microwave MEMS devices into rectangular waveguide with conductive polymer interposers
Open this publication in new window or tab >>Integration of microwave MEMS devices into rectangular waveguide with conductive polymer interposers
2013 (English)In: Journal of Micromechanics and Microengineering, ISSN 0960-1317, E-ISSN 1361-6439, Vol. 23, no 12, 125020- p.Article in journal (Refereed) Published
Abstract [en]

This paper investigates a novel method of integrating microwave microelectromechanical systems (MEMS) chips into millimeter-wave rectangular waveguides. The fundamental difficulties of merging micromachined with macromachined microwave components, in particular, surface topography, roughness, mechanical stress points and air gaps interrupting the surface currents, are overcome by a double-side adhesive conductive polymer interposer. This interposer provides a uniform electrical contact, stable mechanical connection and a compliant stress distribution interlayer between the MEMS chip and a waveguide frame. The integration method is successfully implemented both for prototype devices of MEMS-tuneable reflective metamaterial surfaces and for MEMS reconfigurable transmissive surfaces. The measured insertion loss of the novel conductive polymer interface is less than 0.4 dB in the E-band (60-90 GHz), as compared to a conventional assembly with an air gap of 2.5 dB loss. Moreover, both dc biasing lines and mechanical feedthroughs to actuators outside the waveguide are demonstrated in this paper, which is achieved by structuring the polymer sheet xurographically. Finite element method simulations were carried out for analyzing the influence of different parameters on the radio frequency performance.

Keyword
waveguide integration, conductive polymer interposer, microwave MEMS, RF MEMS
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-104311 (URN)10.1088/0960-1317/23/12/125020 (DOI)000327437000020 ()2-s2.0-84889026540 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 224197
Note

QC 20140113.  Updated from accepted to published.

Available from: 2012-10-31 Created: 2012-10-31 Last updated: 2017-12-07Bibliographically approved
3. Waveguide-integrated MEMS-based phase shifter for phased array antenna
Open this publication in new window or tab >>Waveguide-integrated MEMS-based phase shifter for phased array antenna
Show others...
2014 (English)In: IET Microwaves, Antennas & Propagation, ISSN 1751-8725, E-ISSN 1751-8733, Vol. 8, no 4, 235-243 p.Article in journal (Refereed) Published
Abstract [en]

This study investigates a new concept of waveguide-based W-band phase shifters for applications in phased array antennas. The phase shifters are based on a tuneable bilateral finline bandpass filter with 22 microelectromechanical system (MEMS) switching elements, integrated into a custom-made WR-12 waveguide with a replaceable section, whose performance is also investigated in this study. The individual phase states are selected by changing the configuration of the switches bridging the finline slot in specific positions; this leads to four discrete phase states with an insertion loss predicted by simulations better than 1 dB, and a phase shift span of about 270°. MEMS chips have been fabricated in fixed positions, on a pair of bonded 300 µm high-resistivity silicon substrates, to prove the principle, that is, they are not fully functional, but contain all actuation and biasing-line elements. The measured phase states are 0, 56, 189 and 256°, resulting in an effective bit resolution of 1.78 bits of this nominal 2 bit phase shifter at 77 GHz. The measured insertion loss was significantly higher than the simulated value, which is assumed to be attributed to narrow-band design of the devices as the influences of fabrication and assembly tolerances are shown to be negligible from the measurement results.

Keyword
Rf-Mems, Band, Optimization, Technology, Circuits, Switches, Systems, Filters, Design
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-124588 (URN)10.1049/iet-map.2013.0256 (DOI)000332964300004 ()2-s2.0-84896360317 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 224197
Note

QC 20140317

Available from: 2013-07-15 Created: 2013-07-15 Last updated: 2017-12-06Bibliographically approved
4. Parameter Analysis of Millimeter-Wave Waveguide Switch Based on a MEMS-Reconfigurable Surface
Open this publication in new window or tab >>Parameter Analysis of Millimeter-Wave Waveguide Switch Based on a MEMS-Reconfigurable Surface
2013 (English)In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 61, no 12, 4396-4406 p.Article in journal (Refereed) Published
Abstract [en]

This paper presents a novel concept of a millimeter-wave waveguide switch based on amicroelectromechanical (MEMS)-reconfigurable surface with insertion loss and isolation very similar to high performance but bulky rotary waveguide switches, despite its thickness of only 30 mu m. A set of up to 1470 micromachined cantilevers arranged in vertical columns are actuated laterally by on-chip integrated MEMS comb-drive actuators, to switch between the transmissive state and the blocking state. In the blocking state, the surface is reconfigured so that the wave propagation is blocked by the cantilever columns short-circuiting the electrical field lines of the TE10 mode. A design study has been carried out identifying the performance impact of different design parameters. The RF measurements (60-70 GHz) of fabricated, fully functional prototype chips show that the devices have an isolation between 30 and 40 dB in the OFF state and an insertion loss between 0.4 and 1.1 dB in the ON state, of which the waveguide-assembly setup alone contributes 0.3 dB. A device-level yield analysis was carried out, both by simulations and by creating artificial defects in the fabricated devices, revealing that a cantilever yield of 95% is sufficient for close-to-best performance. The actuation voltage of the active-opening/active-closing actuators is 40-44 V, depending on design, with high reproducibility of better than (sigma = 0.0605 V). Lifetime measurements of the all-metal, monocrystalline-silicon core devices were carried out for 14 h, after which 4.3 million cycles were achieved without any indication of degradation. Furthermore, a MEMS-switchable waveguide iris based on the reconfigurable surface is presented.

Keyword
RF MEMS, reconfigurable surface, waveguide switch, microwave switch, MEMS switches, MEMS components and techniques, millimeter-waves
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-124590 (URN)10.1109/TMTT.2013.2287682 (DOI)000327952100043 ()2-s2.0-84890437665 (Scopus ID)
Note

QC 20140108. Updated from accepted to published.

Available from: 2013-07-15 Created: 2013-07-15 Last updated: 2017-12-06Bibliographically approved
5.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.
6. MEMS-based Reconfigurable Transmit-Array Antenna for 77-GHz Automotive Radar Applications
Open this publication in new window or tab >>MEMS-based Reconfigurable Transmit-Array Antenna for 77-GHz Automotive Radar Applications
Show others...
(English)Manuscript (preprint) (Other academic)
Abstract [en]

This paper presents an alternative solution for reconfigurable beam-steering front-ends consisting of a waveguide-based transmit-array antenna with MEMS-based waveguide-integrated phase shifters used as individual building blocks. The antenna array configuration is implemented with 210 phase shifters integrated in WR-12 rectangular waveguides (60-90 GHz, inner dimensions 3.099 mm × 1.55 mm) with operating frequency of 77 GHz. The phase shifters are based on tunable bilateral finline bandpass filter with microelectromechanical system (MEMS) switching elements integrated in the finline slot. The phase states are controlled by a suitable combination of open and closed states of the individual MEMS switches. The proof-of-concept prototype of the proposed antenna array has been fabricated and characterized. For this prototype, beam-steering capability of the transmit-array antenna is shown by shifting the horn antenna feed.  The transmit-array array exhibits good performance up to 15° over the measured frequency band with HPBW of 4.5º-5.5º while the horn feed is shifted up to 12 mm from the initial central position.

Keyword
RF MEMS, antenna array, automotive radar
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-143039 (URN)
Note

QS 2014

Available from: 2014-03-14 Created: 2014-03-14 Last updated: 2014-03-17Bibliographically approved

Open Access in DiVA

Zargham_Baghchehsaraei_PhD_Thesis(7550 kB)1294 downloads
File information
File name FULLTEXT01.pdfFile size 7550 kBChecksum SHA-512
bb571c96c663e91fd96f41a82fa0780f51540779316b12a735a6e5ed911eeccc63200f7676164ba705c7637945f7fa67be00e5a6f309820c8509b110fe621cc9
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Baghchehsaraei, Zargham
By organisation
Micro and Nanosystems
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 1294 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 882 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf