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
A highly tunable microwave oscillator based on MTJ STO technology
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.ORCID iD: 0000-0002-1686-7923
KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Material Physics, MF.
Show others and affiliations
2014 (English)In: Microwave and optical technology letters (Print), ISSN 0895-2477, E-ISSN 1098-2760, Vol. 56, no 9, 2092-2095 p.Article in journal (Refereed) Published
Abstract [en]

This article presents a fully ESD-protected, highly tunable microwave oscillator based on magnetic tunnel junction (MTJ) spin torque oscillator (STO) technology. The oscillator consists of a compact MTJ STO and a 65 nm CMOS wideband amplifier, which amplifies the RF signal of the MTJ STO to a level that can be used to drive a PLL. The (MTJ STO+amplifier IC) pair shows a measured quality factor (Q) of 170 and a wide tunability range from 3 to 7 GHz, which demonstrate its potential to be used as a microwave oscillator in multiband, multistandard radios.

Place, publisher, year, edition, pages
2014. Vol. 56, no 9, 2092-2095 p.
Keyword [en]
spin torque oscillator, CMOS, microwave, wideband, highly tunable
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:kth:diva-149496DOI: 10.1002/mop.28511ISI: 000339439000033Scopus ID: 2-s2.0-84903286907OAI: oai:DiVA.org:kth-149496DiVA: diva2:740080
Funder
Swedish Research Council
Note

QC 20140822

Available from: 2014-08-22 Created: 2014-08-22 Last updated: 2017-12-05Bibliographically approved
In thesis
1. Spin Torque Oscillator Modeling, CMOS Design and STO-CMOS Integration
Open this publication in new window or tab >>Spin Torque Oscillator Modeling, CMOS Design and STO-CMOS Integration
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Spin torque oscillators (STOs) are microwave oscillators with an attractive blend of features, including a more-than-octave tunability, GHz operating frequencies, nanoscale size, nanosecond switching speed and full compatibility with CMOS technology. Over the past decade, STOs' physical phenomena have been explored to a greater extent, their performance has been further improved, and STOs have already shown great potential for a wide range of applications, from microwave sources and detectors to neuromorphic computing. This thesis is devoted to promoting the STO technology towards its applications, by means of implementing the STO's electrical model, dedicated CMOS integrated circuits (ICs), and STO-CMOS IC integration.

An electrical model, which can capture magnetic tunnel junction (MTJ) STO's characteristics, while enabling system- and circuit-level designs and performance evaluations, is of great importance for the development of MTJ STO-based applications. A comprehensive and compact analytical model, which is based on macrospin approximations and can fulfill the aforementioned requirements, is proposed. This model is fully implemented in Verilog-A, and can be used for efficient simulations of various MTJ STOs. Moreover, an accurate phase noise generation approach, which ensures a reliable model, is proposed and successfully used in the Verilog-A model implementation. The model is experimentally validated by three different MTJ STOs under different bias conditions.

CMOS circuits, which can enhance the limited output power of MTJ STOs to levels that are required in different applications, are proposed, implemented and tested. A novel balun-low noise amplifier (LNA), which can offer sufficient gain, bandwidth and linearity for MTJ STO-based magnetic field sensing applications, is proposed. Additionally, a wideband amplifier, which can be connected to an MTJ STO to form a highly-tunable microwave oscillator in a phase-locked loop (PLL), is also proposed. The measurement results demonstrate that the proposed circuits can be used to develop MTJ STO-based magnetic field sensing and microwave source applications.

The investigation of possible STO-CMOS IC integration approaches demonstrates that the wire-bonding-based integration is the most suitable approach. Therefore, a giant magnetoresistance (GMR) STO is integrated with its dedicated CMOS IC, which provides the necessary functions, using the wire-bonding-based approach. The RF characterization of the integrated GMR STO-CMOS IC system under different magnetic fields and DC currents shows that such an integration can eliminate wave reflections. These findings open the possibility of using GMR STOs in magnetic field sensing and microwave source applications.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. xxvi, 81 p.
Series
TRITA-ICT, 2015:19
Keyword
STO technology, microwave oscillator, analytical model, macrospin approximation, Verilog-A model, high frequency CMOS circuits, balun-LNA, STO-IC integration
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Information and Communication Technology
Identifiers
urn:nbn:se:kth:diva-176890 (URN)978-91-7595-750-0 (ISBN)
Public defence
2015-12-07, Sal C, Isafjordsgatan 22, Kista, 13:00 (English)
Opponent
Supervisors
Funder
Swedish Research Council
Note

QC 20151112

Available from: 2015-11-12 Created: 2015-11-11 Last updated: 2015-11-12Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Authority records BETA

Chen, TingsuRusu, Ana

Search in DiVA

By author/editor
Chen, TingsuRodriguez, SaulÅkerman, JohanRusu, Ana
By organisation
Integrated Devices and CircuitsMaterial Physics, MF
In the same journal
Microwave and optical technology letters (Print)
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 245 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