PTAB

IPR2018-01463

ZTE (USA), Inc. v. Fractus, S.A.

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1. Case Identification

2. Patent Overview

  • Title: Multilevel Antennas
  • Brief Description: The ’617 patent is directed to multilevel antennas designed to operate in multiple frequency bands while maintaining a small size. The technology features a geometric structure composed of individual, electromagnetically coupled polygons or polyhedrons of the same type, arranged to create multiple levels of detail and empty spaces that allow for longer, winding current paths.

3. Grounds for Unpatentability

Ground 1: Claims 1-4 and 6-20 are obvious over Misra I in view of Misra II.

  • Prior Art Relied Upon: Misra I (a 1998 IEEE journal article titled "Study of Impedance and Radiation Properties of a Concentric Microstrip Triangular-Ring Antenna...") and Misra II (a 1996 Microwave and Optical Technology Letters article titled "Experimental Investigations on the Impedance and Radiation Properties of a Three-Element Concentric Microstrip Antenna.").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Misra I discloses a concentric microstrip triangular-ring antenna (CMTRA) that meets most limitations of the independent claims. Misra I’s antenna is a multilevel structure (overall triangle vs. component polygons) usable at three frequency ranges, with different portions of the antenna radiating at different frequencies. Critically, Misra I discloses that the overall triangular structure (3 sides) is composed of smaller four-sided polygons, satisfying the limitation that the perimeter of the structure has a different number of sides than the figures that compose it. To the extent Misra I does not explicitly teach that the geometric elements are electromagnetically coupled to enhance bandwidth, Petitioner contended that Misra II provides this teaching. Misra II, from the same authors, expressly teaches using electromagnetic coupling in a concentric square-ring antenna to significantly enhance bandwidth.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Misra I and Misra II because both references address the same problem of designing small, multiband antennas. A POSITA would have been motivated to apply the express teaching of electromagnetic coupling from Misra II to the similar concentric ring antenna of Misra I to achieve the known benefit of increased bandwidth.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination. Both references describe similar concentric microstrip ring antennas (triangular vs. square) and are from the same authors, making the application of a known performance-enhancement technique (coupling) from one design to the other a predictable modification.

Ground 2: Claims 1-4 and 6-20 are obvious over Grangeat.

  • Prior Art Relied Upon: Grangeat (Patent 6,133,879).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Grangeat, by itself, renders the challenged claims obvious. Grangeat discloses a multifrequency microstrip antenna for portable telephones that operates on at least three frequency bands. Petitioner’s simulations of Grangeat’s antenna showed different portions (zones) of the structure radiating at different frequencies. The structure is composed of multiple identifiable four-sided polygons (rectangles). Importantly, the overall perimeter of the Grangeat antenna has 28 sides, while the individual polygons composing it have four sides, thus disclosing a key limitation. Grangeat also discloses that its zones are electromagnetically coupled through direct contact and proximity (an axial gap), satisfying the coupling requirement.
    • Motivation to Combine: Not applicable (single reference ground).
    • Expectation of Success: Not applicable (single reference ground).

4. Key Claim Construction Positions

  • "structure for the multiband antenna": Petitioner proposed construing this term to mean a multilevel structure with at least two levels of detail, where the levels are composed of polygons of the same type, and where most (more than 75%) of the polygons are clearly visible and have less than 50% of their perimeter in contact with other elements. This construction incorporates the specific structural limitations from the patent's specification, which Petitioner argued is necessary to define the invention and is consistent with a PTO construction in a related reexamination.
  • "a [second/third] portion located substantially within the first portion": Petitioner argued this should be construed to mean a portion that is "substantially inside or enclosed by the first portion," where the portions differ in size or configuration. This construction was asserted to be narrower than the Patent Owner's proposed construction and was allegedly adopted by the PTO in a related proceeding.
  • "closed figures bounded by the same number of sides": Petitioner proposed a narrow construction of "straight-side polygon...or a figure bound by a circle, or a figure bound by an ellipse." This was presented as a narrower alternative to the Patent Owner's position and was applied for the purposes of the petition.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under §325(d) would be inappropriate. Although the prior art references (Misra I, Misra II, and Grangeat) were listed in an Information Disclosure Statement (IDS) during prosecution, Petitioner contended there is no evidence the Examiner substantively considered the specific disclosures cited in the petition. Furthermore, the petition presented new expert testimony and analysis that were not before the Examiner, creating a different record for the Board to consider.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-4 and 6-20 of the ’617 patent as unpatentable.