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
Three-dimensional micromachined silicon-substrate integrated millimetre-wave helical antennas
KTH, School of Electrical Engineering (EES), Micro and Nanosystems. (RF MEMS)
KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
2013 (English)In: IET Microwaves, Antennas & Propagation, ISSN 1751-8725, E-ISSN 1751-8733, Vol. 7, no 4, 291-298 p.Article in journal (Refereed) Published
Abstract [en]

This study presents a design study of a novel concept of a three-dimensional (3D) micromachined square helical antenna designed for 75 GHz, which is completely integrated into a semiconductor silicon substrate. In contrast to conventional on-chip integrated antennas which typically are built on top of the substrate surface, the proposed antenna concept utilises, for the first time to the knowledge of the authors, the whole volume of the wafer by building the helical structure inside the substrate, which results in a very area-efficient high-gain radiating element for a substrate-integrated millimeter-wave system. The effective permittivity of the antenna core and the surrounding substrate can be tailor-made by 3D micromachining, for optimising the maximum antenna performance with this design study it was found, that such an antenna concept can achieve a maximum gain of 13.2 dBi, a radiation efficiency of 95.3% at the axial ratio of 0.94 and a half-power beamwidth (HPBW) of smaller than 40 degrees, and a return loss S11 of -22.3 dB at the nominal frequency of 74.5 GHz, with a 15-GHz bandwidth with a reflection coefficient better than -10 dB. A 16-element substrate-integrated helical line array is demonstrated and achieves a maximum gain of 24.2 dBi with a HPBW of 6.3 degrees in the y-z-plane. This study also studies intensively the influences of the surrounding silicon substrate and dielectric-core etching, the matching transition between the helical structure and a coplanar-waveguide feeding, as well as size and geometry of the ground structure.

Place, publisher, year, edition, pages
2013. Vol. 7, no 4, 291-298 p.
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-91537DOI: 10.1049/iet-map.2012.0345ISI: 000321706200010Scopus ID: 2-s2.0-84891641764OAI: oai:DiVA.org:kth-91537DiVA: diva2:510611
Funder
Vinnova
Note

QC 20130814. Updated from accepted to published

Available from: 2012-03-17 Created: 2012-03-17 Last updated: 2017-12-07Bibliographically approved
In thesis
1. Novel RF MEMS Devices for W-Band Beam-Steering Front-Ends
Open this publication in new window or tab >>Novel RF MEMS Devices for W-Band Beam-Steering Front-Ends
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis presents novel millimeter-wave microelectromechanical-systems (MEMS) components for W-band reconfigurable beam-steering front-ends. The proposed MEMS components are novel monocrystalline-silicon dielectric-block phase shifters, and substrate-integrated three-dimensional (3D) micromachined helical antennas designed for the nominal frequency of 75 GHz.

The novel monocrystalline-silicon dielectric-block phase shifters are comprised of multi-stages of a tailor-made monocrystalline-silicon block suspended on top of a 3D micromachined coplanar-waveguide transmission line. The relative phase-shift is obtained by vertically pulling the suspended monocrystalline-silicon block down with an electrostatic actuator, resulting in a phase difference between the up and downstate of the silicon block. The phase-shifter prototypes were successfully implemented on a high-resistivity silicon substrate using standard cleanroom fabrication processes. The RF and non-linearity measurements indicate that this novel phase-shifter design has an excellent figure of merit that offers the best RF performance reported to date in terms of loss/bit at the nominal frequency, and maximum return and insertion loss over the whole W-band, as compared to other state-of-the-art MEMS phase shifters. Moreover, this novel design offers high power handling capability and superior mechanical stability compared to the conventional MEMS phase-shifter designs, since no thin moving metallic membranes are employed in the MEMS structures. This feature allows MEMS phase-shifter technology to be utilized in high-power applications. Furthermore, the return loss of the dielectric-block phase shifter can be minimized by appropriately varying the individual distance between each phase-shifting stage.

This thesis also investigates 3D micromachined substrate-integrated W-band helical antennas. In contrast to conventional on-chip antenna designs that only utilize the surface of the wafer, the novel helical radiator is fully embedded into the substrate, thereby utilizing the whole volume of the wafer and resulting in a compact high-gain antenna design. The performance of the antenna is substantially enhanced by properly etching the substrate, tailor making the antenna core, and by modifying size and geometry of the substrate-integrated ground plane. A linear line antenna array is composed of eight radiating elements and is demonstrated by simulations. Each antenna is connected to the input port through a multi-stage 3-dB power divider. The input and output of the single-stage 3-dB power divider is well matched to the 50-Ω impedance by four-section Chebyshev transformers. The simulation results indicate that the novel helical antenna arrays offer a narrow radiation beam with an excellent radiation gain that result in high-resolution scan angles on the azimuth plane. The proposed helical antenna structures can be fabricated by employing standard cleanroom micromachining processes.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. xii, 84 p.
Series
Trita-EE, ISSN 1653-5146 ; 2012:011
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-93507 (URN)978-91-7501-296-4 (ISBN)
Public defence
2012-05-25, Q1, Osquldas väg 4, entréplan, KTH, Stockholm, 09:30 (English)
Opponent
Supervisors
Note
QC 20120427Available from: 2012-04-27 Created: 2012-04-19 Last updated: 2012-04-27Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Somjit, NutapongOberhammer, Joachim
By organisation
Micro and Nanosystems
In the same journal
IET Microwaves, Antennas & Propagation
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 163 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