Techniques for precision high-frequency (RF to THz) characterization of electronic components, materials, and biological samples (Impact Case Study 2)
Submitting Institution
University of LeedsUnit of Assessment
Electrical and Electronic Engineering, Metallurgy and MaterialsSummary Impact Type
TechnologicalResearch Subject Area(s)
Technology: Communications Technologies
Summary of the impact
    Research at the University of Leeds, in partnership with the US company
      Agilent Technologies,
      has directly resulted in the development of high performance vector
      network analyzer
      instrumentation used by electronics, aerospace and defence companies
      globally to measure the
      high frequency properties of electronic devices and materials. University
      of Leeds research also
      directly resulted in the development of two further Agilent Technologies
      products — a high
      frequency dielectric probe kit and a capacitance scanning probe
      microscope. Agilent Technologies
      confirms that the collective sales of these products are in the region of
      tens of millions of dollars
      annually since 2008.
    Underpinning research
    The University of Leeds has a long-standing collaboration with Agilent
      Technologies (formerly
      Hewlett Packard) dating back to 1981 when Professor Roger Pollard,
      then lecturer in the School of
      Electronic and Electrical Engineering, took up a consultancy position with
      Agilent Technologies,
      Santa Rosa, California. Pollard subsequently assumed an on-going R&D
      consultancy role in the
      company, visiting each summer, until 2010 when he retired from the
      University and took up a
      permanent, part-time, position with Agilent.
    Pollard's research focussed on the study of solid-state devices and
      circuits operating at microwave
      frequencies, and in particular the development of techniques to measure
      the high frequency
      properties (from a few megahertz up to the terahertz frequency range) of
      electronic devices and
      materials. His research exploited vector network analyzers, which are used
      to measure these high
      frequency electronic properties — a high frequency signal is applied to a
      device or material and the
      output signal analyzed. Key characteristics, termed S-parameters, are
      measured, which show
      what proportion of the input radiation is absorbed and what is reflected
      by the material or device-
      under-test, and how this changes as a function of frequency.
    A key focus of Leeds research since 1993 has been the development of new
      algorithms to quantify
      and extract background noise from S-parameter measurements. This research,
      led by Pollard,
      resulted in a theory for error correction and noise figure analysis in
      1994. An algorithm was
      developed using load pull measurements to establish very accurate
      impedance and noise states,
      working with Agilent to develop the mathematics to derive a noise figure
      from these noise state
      measurements [1]. These algorithms now underpin the operation of all
      Agilent network analyzers,
      including the PNA-X platform launched in 2008.
    In 1997, Leeds researchers under Pollard reported a new way to measure
      the high frequency
      properties of materials without the need for the test material to have
      integral electrical contacts.
      Instead, an open-ended coaxial cable is placed on the surface of the test
      sample [2]. Supported in
      part by EPSRC award GR/K00783 (£114,320, 1994-1996), Pollard developed the
      algorithms that
      allow accurate extraction of the microwave frequency properties of
      materials by this method
      without needing to form any fixed waveguide on the material surface. The
      results of this research
      form the basis of Agilent's 8507E dielectric probe kit launched in 2009,
      and the body of work to
      date led, in part, to a major JIF/EPSRC award in 2001 (GR/M87535,
      £2,188,383, 2001-2003),
      which developed a 300 GHz microwave and millimeter-wave instrumentation
      facility at Leeds.
    In 2008, Pollard's group (now including Hunter who joined the
      University from Filtronic in 1998)
      developed the world's first substrate integrated waveguide sensor for
      measuring microwave
      properties of small volumes of liquid solvents [3]. This work (carried out
      in part while Pollard's PhD
      student, Saeed, was on a five month GRASS-ROOT internship at Agilent in
      2008) formed the basis
      for the development of Agilent's scanning capacitance probe microscope.
      This is a modified
      atomic force microscope, which not only produces topographical and
      morphological images of a
      surface — as is standard — but also provides information on the high
      frequency dielectric properties
      of the surface under examination, allowing doping maps of semiconductors
      to be produced, for
      example. The latter application has seen widespread sales of this
      equipment across the
      semiconductor sector, inter alia.
    For his scientific and engineering contributions internationally, Pollard
      was elected as an IEEE
      Fellow in 1997. He served as president of the IEEE Microwave Theory and
      Techniques Society
      (MTT-S) in 1998, received the IEEE Third Millennium Medal in 2000, was
      elected to a Fellowship
      of the Royal Academy of Engineering in 2005, and received the MTT-S
      Distinguished Service
      Award in 2006. He was also a Fellow of the Institution of Engineering and
      Technology.
    Key researchers:
    Roger Pollard (Senior Lecturer, 01/10/1985 - 31/07/1998; Professor,
      01/08/1998 - 30/09/2010,
      when he retired). Pollard also served as Head of the School of Electronic
      and Electrical
      Engineering (1999-2002), and inaugural Dean of the Faculty of Engineering
      (2002-2010).
      Ian Hunter (Senior Research Fellow, 01/08/1998-31/08/2001; Reader,
      01/09/2001-31/05/2003;
      and Professor, 01/06/2003-present).
    References to the research
    
[1] C E Collins, R D Pollard, R E Miles and R
      Dildine, `A new method for determination of
      single sideband noise figure', IEEE Transactions on Microwave Theory
        and Techniques 42,
      2435-2439 (1994). DOI: 10.1109/22.339778.
     
[2] D V Blackham and R D Pollard, `An improved technique for
      permittivity measurements using
      a coaxial probe', IEEE Transactions on Instrumentation and Measurement
      46, 1093-1099
      (1997). DOI: 10.1109/19.676718.
     
[3] K Saeed, R D Pollard and I C Hunter,
      `Substrate integrated waveguide cavity resonators for
      complex permittivity characterization of materials', IEEE Transactions
        on Microwave Theory
        and Techniques 56, 2340-2347 (2008). DOI: 10.1109/TMTT.2008.2003523.
     
Leeds researchers in bold.
    These outputs are all published in internationally leading peer-reviewed
      archival journals, and are
      recognised internationally in terms of originality, significance and
      rigour. All three outputs underpin
      the impact described in this case study.
    Details of the impact
    The underpinning University of Leeds research has had a direct and
      substantial economic impact
      during the review period through sales generated by Agilent Technologies.
      Our research has also
      had a broader impact through the companies within the electronics sector
      that have bought the
      Agilent Technologies instrumentation for the design and testing of new
      products, which were
      themselves released onto the market. Further impact has been generated
      through the use of this
      instrumentation in, for example, the metrology and standards industry.
    The PNA-X platform, which is the microwave industry's highest performing
      network analyzer in
      terms of its noise performance and accuracy, together with portable RF
      analyzers incorporating the
      same technology (the FieldFox platform), are sold to the wireless,
      aerospace and defence
      industries and were all directly brought about by research at Leeds [A].
      The results from the
      research on noise measurement [1] were incorporated into the PNA-X
      platform as an option from
      2008. Customers include (but are not limited to) in aerospace and defence:
      Northrop Grumman,
      Astrium, Selex, Raytheon, multiple defence agencies; in
      telecommunications: NSN, Ericsson,
      Motorola; in computing: Cisco, Huawei, Intel; and, in microwave
      electronics: Mini-circuits, Miteq,
      and Filtronic (itself an earlier spin-out from the School). This work
      contributed to Agilent becoming
      a global leader in network analyzers, with a greater market share than all
      other companies
      combined. Owing to commercial sensitivity, Agilent is unable to provide
      precise figures for sales of
      its products, however, a senior Agilent executive confirms: "The
        revenue from the noise figure
        option to the PNA-X is in the tens of millions of dollars annually"
      [A].
    The algorithms described in reference [2] were incorporated into the
      Agilent dielectric probe
      measurement kit (model number 85070E) in 2009 [A]. The University of Leeds
      related work with
      Agilent on the extraction of material parameters from substrate integrated
      waveguide cavity
      resonators [3] led directly to the Agilent Technologies scanning probe
      microscope range, with
      models 5400 and 5600LS first brought to market in 2009. Specifically, this
      work led to a new
      modality being incorporated into this instrumentation (SMM mode), which
      enables complex
      impedance (resistance and reactance), calibrated capacitance, and
      topography measurements
      within the same instrument [A]. This microscopy modality outperforms
      traditional AFM-based
      scanning capacitance microscopy techniques, since it does not require any
      contact between the
      probe head and the sample. The instrument is now being sold routinely to
      the semiconductor
      industry for calibrated dopant density measurements on silicon wafers, as
      well as to research
      organisations worldwide [A]. Again, precise sales figures of the
      dielectric probe kit and scanning
      probe microscope range are not available for commercial reasons, but a
      senior Agilent executive
      states: "I can confirm that the key academic work on which these
        developments were based was
        published in two papers by Pollard and co-workers (References [2] and
        [3]) ... The specific revenue
        from these solutions is in the tens of millions of dollars annually"
      [A]. Furthermore, "collective sales
        of all these products (network analyzers, open-ended dielectric probes,
        and scanning probe
        microscope) have been in the region of hundreds of millions of dollars
        per year" [A].
    To give one example of the broader impact that University of Leeds
      research has achieved through
      the organizations that have bought Agilent Technologies instrumentation,
      there has been
      substantial impact in the metrology sector, with the network analyzers
      being used by, for example,
      the National Physical Laboratory (NPL) for accurate calibration of high
      frequency instrumentation
      [B]. Agilent's network analyzers, incorporating technologies developed at
      Leeds as discussed
      above, are now considered to be the industry standard for these
      measurements - "we have
        specifically chosen Agilent Technologies Network Analysers for the high
        precision that they offer,
        for their ability to offer state-of-the-art error correction routines,
        and, for their ability to provide
        implementations of the very latest measurement and calibration
        techniques" [B]. NPL has also
      confirmed that the availability of this Agilent Technologies
      instrumentation has enabled them to
      offer a wide range of measurement capabilities to its customers "that
        have led to an income over
        the period 2008-2013 of approximately £50M" [B]. The fan-out/impact
      from the customer
      calibration services also provides a major source of income for many
      third-party laboratories
      involved as links in the measurement assurance/traceability chain — for
      example, one calibration
      from NPL can validate tests made on many thousands of devices on many
      industrial shop floors
      and production lines [B].
    This case study exemplifies how the School of Electronic and Electrical
      Engineering at Leeds
      adopts a long-term and sustainable approach towards ensuring the impact of
      its research. Agilent
      Technologies (and formerly Hewlett Packard) have sponsored 15 PhD students
      in the School over
      this on-going period of collaboration. Furthermore, the School has also
      trained a number of
      researchers who have taken up employment with Agilent, providing further
      impact from the
      research. Four current staff at the company obtained their doctoral
      degrees through work
      performed in collaboration with Leeds, under the supervision of Pollard.
      The staff are: Mark
      Pierpoint (PhD completed 1987), who is currently Vice President/General
      Manager of the Software
      and Modular Solutions Business section of Agilent; Loren Betts (PhD 2009),
      an engineer
      responsible for many of the Agilent's vector network analyzer products;
      Dave Blackham (PhD
      1999) who specializes in measurement uncertainties; and, Joel Dunsmore
      (PhD 2004), an Agilent
      Fellow developing measurement applications.
    Sources to corroborate the impact 
    [A] Testimonial from a General Manager, Agilent Technologies, 1400
      Fountaingrove Parkway,
      Santa Rosa, CA 95403, 19 September 2012.
    [B] Testimonial from the Lead Scientist (RF & Microwave Measurements
      division), National
      Physical Laboratory, Teddington, Middlesex, 9 September 2013.