PTAB

IPR2018-01451

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

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1. Case Identification

  • Case #: IPR2018-01451
  • Patent #: U.S. Patent No. 7,397,431
  • Filed: August 3, 2018
  • Petitioner(s): ZTE (USA), INC.
  • Patent Owner(s): FRACTUS S.A.
  • Challenged Claims: 2, 3, 6, 11, 14-16, 18, 20, 23, 28, 30, 32, and 38-43

2. Patent Overview

  • Title: Multilevel Antennae
  • Brief Description: The ’431 patent describes multi-band antennae featuring a "multilevel" geometry. The design uses multiple, electromagnetically coupled geometric elements (like polygons) to form a larger structure, which allows the antenna to operate in multiple frequency bands while maintaining a small size.

3. Grounds for Unpatentability

Ground 1: Obviousness over Misra I - Claims 2, 3, 6, 18, 23, and 32 are obvious over Misra I.

  • Prior Art Relied Upon: Misra I (an Apr. 1998 IEEE publication titled "Study of Impedance and Radiation Properties of a Concentric Microstrip Triangular-Ring Antenna...").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Misra I, which was not cited during the original prosecution, discloses all limitations of the challenged claims. Misra I teaches a multi-band, concentric microstrip triangular-ring antenna (CMTRA). Petitioner asserted this CMTRA is a "multilevel structure" comprising multiple "geometric elements" (the legs of the concentric triangles). It is disclosed as operating in multiple frequency bands, with simulations showing different portions of the antenna are associated with different bands. The spaces between the triangular rings create a circuitous current path, and the radiation patterns are substantially similar across the operating bands, thus meeting the core limitations of the base claims.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the argument was that Misra I inherently contained all the elements, making their combination obvious. A person of ordinary skill in the art (POSITA) would have recognized Misra I's structure as a small, multi-band antenna solution and would have found it obvious to apply its teachings to create the claimed invention.

Ground 2: Obviousness over Misra I and Misra II - Claims 2, 3, 6, 11, 14-16, 18, 20, 23, 28, 30, 32, and 38-43 are obvious over Misra I in view of Misra II.

  • Prior Art Relied Upon: Misra I and Misra II (a Feb. 1996 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: This ground builds on Ground 1 by adding Misra II to teach that modifying the overall shape of a concentric-ring antenna is a known design choice. For example, claims 14 and 30 require the perimeter of the multilevel structure to have a different number of sides than the geometric elements composing it. Misra I's triangular structure (3 sides) is composed of four-sided polygons, already meeting this. However, Misra II, by the same authors, discloses a square-ring antenna. Petitioner contended that combining the teachings makes it obvious that the overall shape is a design choice, and a POSITA could have implemented other shapes (e.g., a pentagon), where the perimeter would have a greater number of sides than the four-sided elements.
    • Motivation to Combine (for §103 grounds): A POSITA would combine Misra I and Misra II because they were written by the same authors, address the same problem of creating small, multi-band microstrip antennas, and share the same design goals. Misra II simply shows an alternative, predictable configuration (square instead of triangle), motivating a POSITA to view the overall antenna shape as a variable design choice.
    • Expectation of Success: Success would be expected because the combination merely involved applying a known antenna shape (from Misra II) to an analogous antenna structure (Misra I), which is a predictable modification.

Ground 3: Obviousness over Grangeat - Claims 2, 3, 6, 11, 14-16, 18, 20, 23, 28, 30, 32, and 38-43 are obvious over Grangeat.

  • Prior Art Relied Upon: Grangeat (Patent 6,133,879).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Grangeat, which discloses a "multifrequency microstrip antenna" for portable telephones, renders the claims obvious. Grangeat teaches an antenna with multiple "zones" or geometric elements arranged to provide a multilevel structure. These zones define slots that lengthen current paths, and different combinations of zones are associated with different operating frequency bands. Petitioner asserted that Grangeat's structure, composed of nested polygons, meets all limitations, including having portions located within other portions, operating in multiple frequency bands, and having a perimeter with a different number of sides than its constituent elements.
    • Motivation to Combine (for §103 grounds): As a single-reference ground, the motivation was that Grangeat teaches an integrated solution for a multi-band antenna in a portable device. A POSITA would have recognized all the claimed features as being present in the Grangeat disclosure for the purpose of achieving a compact, multi-band antenna.

4. Key Claim Construction Positions

  • "multilevel structure": Petitioner proposed a detailed construction meaning a structure with at least two levels of detail, composed of polygons of the same type, where most (>75%) are individually distinguishable and have an area of contact with other polygons of less than 50% of their perimeter. Petitioner applied this narrow construction, which was consistent with a prior PTO construction in a reexamination, to preemptively address potential arguments from the Patent Owner.
  • "said second portion being located substantially within the first portion": Petitioner argued this means the second portion is simply inside or enclosed by the first. This is contrasted with the Patent Owner's position that it requires sharing a "substantial number of geometric elements." Petitioner argued its construction was correct and adopted it for its analysis.
  • "overall structure of the conductive radiating element": Petitioner adopted the Patent Owner's proposed construction—"any portion of the antenna that radiates in one or more of the claimed frequency bands"—for the purposes of the petition.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that institution would not be improper under §325(d) because the asserted grounds were not the same or substantially the same as those previously considered by the PTO.
  • It was argued that the combination of Misra I and Misra II was never considered by the PTO in any prior examination or reexamination proceeding.
  • It was further argued that while Grangeat was previously submitted in a reexamination request, the PTO denied that request because it did not include sufficient particulars on Grangeat's antenna characteristics. This petition, by contrast, provided detailed expert testimony and analysis, presenting a new question of patentability.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 2, 3, 6, 11, 14-16, 18, 20, 23, 28, 30, 32, and 38-43 of the ’431 patent as unpatentable.