PTAB

IPR2018-01451

ZTE USA Inc v. Fractus SA

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Multilevel Antennae
  • Brief Description: The ’431 patent discloses multilevel antennae designed for multi-band frequency operation and reduced size. The technology is based on using a repeating geometry of individual polygons ("geometric elements") that are electromagnetically coupled to form a larger, complex structure with at least two levels of structural detail.

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 ("Study of Impedance and Radiation Properties of a Concentric Microstrip Triangular-Ring Antenna...", a 1998 IEEE journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Misra I disclosed all limitations of the base claims for the challenged dependent claims. Misra I taught a multi-band, three-element concentric microstrip triangular-ring antenna (CMTRA) that constituted a "multilevel structure." This structure was composed of identifiable four-sided polygons (the legs of each triangle) that were electromagnetically coupled, operated at multiple frequencies, and had less than 50% of their perimeter in contact with other polygons. This configuration created empty spaces that provided a circuitous current path, a key feature of the challenged claims.
    • Key Aspects: Petitioner supported its contentions with expert-run simulations of the Misra I antenna, which reportedly confirmed its multi-band performance and demonstrated that different portions of the antenna were associated with different frequency bands, exhibiting substantially similar radio-electric behavior.

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

  • Prior Art Relied Upon: Misra I (a 1998 IEEE journal article) and Misra II ("Experimental Investigations on the Impedance and Radiation Properties of a Three-Element Concentric Microstrip Antenna," a 1996 journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Misra I taught most limitations as detailed in Ground 1. The combination with Misra II, authored by the same individuals, was argued to render obvious additional limitations, particularly those in claims 38-43. Misra II disclosed a similar concentric microstrip antenna but with a square-ring shape instead of Misra I's triangular shape. This combination allegedly made it obvious that the perimeter of the multilevel structure could have a different, and specifically a greater, number of sides than the individual geometric elements composing it. Misra II also explicitly taught an "electromagnetically coupled concentric microstrip" antenna, reinforcing the obviousness of this feature.
    • Motivation to Combine: A POSITA designing a small, multi-band antenna would combine the teachings of Misra I and Misra II. Both references addressed the same technical problem, were from the same authors, and presented similar concentric-ring structures that differed only in their polygonal shape. The combination would suggest to a POSITA that the overall shape of the antenna was a predictable design choice to achieve desired performance characteristics.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in applying the concentric-ring design to other polygonal shapes (e.g., pentagonal) to achieve similar multi-band benefits without undue experimentation.

Ground 3: Obviousness over Grangeat - Claims 2, 3, 6, 11, 14-16, 18, 20, 23, 28, 30, 32, 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 disclosed a "multifrequency microstrip antenna" for portable telephones, independently rendered the claims obvious. Grangeat's antenna used multiple conductive zones and slots to create a multilevel structure. Petitioner’s simulations showed that different portions of the antenna (composed of groups of zones) radiated at different frequency bands, with a smaller portion located within a larger portion as claimed. Grangeat’s slots created empty spaces for a circuitous current path, and its overall structure had a perimeter with more sides than the rectangular geometric elements that composed it, meeting further limitations of the challenged claims.
    • Key Aspects: This ground provided an alternative embodiment (a slotted patch antenna) to the concentric-ring design of Misra. Petitioner used this ground to argue that the claimed concepts were not inventive but were instead common design principles for multi-band antennas known from various configurations in the prior art.

4. Key Claim Construction Positions

  • "multilevel structure": Petitioner proposed a narrow construction for this term, arguing it requires "a structure...with at least two levels of detail...composed of polygons...wherein most (i.e., more than 75%) of the polygons...are clearly visible...and most (i.e., more than 75%) of the polygons...having an area of contact...that is less than 50% of the perimeter or area." This construction, emphasizing specific spacing between elements, was central to Petitioner's argument, as it contended the prior art explicitly met these detailed structural requirements.
  • "said second portion being located substantially within the first portion": Petitioner proposed this term be construed to mean the second portion is "substantially inside or enclosed by the first portion, where the first portion and the second portion differ in size or configuration." This supported Petitioner's mapping of the concentric rings of Misra and the nested conductive zones of Grangeat to the claim language.

5. Relief Requested

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