PTAB
IPR2019-00950
Kathrein USA, Inc. v. Fractus S.A.
1. Case Identification
- Case #: Unassigned
- Patent #: 7,932,870
- Filed: April 9, 2019
- Petitioner(s): KATHREIN USA, INC., T-MOBILE US, INC.
- Patent Owner(s): FRACTUS, S.A.
- Challenged Claims: 1, 4, 5, and 7
2. Patent Overview
- Title: Interlaced Multiband Antenna Arrays
- Brief Description: The ’870 patent discloses a multiband antenna array for wireless communications. The technology is described as creating an "interlaced" or "interleaved" array by juxtaposing multiple conventional single-band (mono-band) antenna arrays and employing a single multiband antenna element at positions where elements from the mono-band arrays would otherwise coincide.
3. Grounds for Unpatentability
Ground 1: Anticipation of Claims 1 and 4 under §102(b)
- Prior Art Relied Upon: Lindmark-I (a 1998 IEEE Aerospace Conference proceeding).
- Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Lindmark-I teaches every limitation of claims 1 and 4. Lindmark-I discloses a dual-band, dual-polarized, stacked-patch antenna element for a base-station antenna array, describing a "linear array of such elements." Petitioner asserted this constitutes an "interlaced multiband antenna array" (claim 1) because each position in the array is occupied by a dual-band element operating simultaneously on two frequency bands (GSM and DCS). The array results from the "juxtaposition" of two mono-band arrays (one for each frequency band), and the central frequencies of these bands (920 MHz and 1795 MHz) do not correspond to an integer divider. For claim 4, Petitioner argued that since every element is dual-band, at least two mono-band elements (one for each band) "come together in each position."
- Key Aspects: The core of the anticipation argument rested on interpreting Lindmark-I's linear array of dual-band elements as inherently meeting the ’870 patent's definition of an "interlaced" array that results from the "juxtaposition" of mono-band arrays.
Ground 2: Obviousness of Claims 1, 4, and 7 under §103(a)
- Prior Art Relied Upon: Lindmark-I (a 1998 IEEE conference proceeding) and Lindmark-II (an October 1998 Nordic Radio Symposium paper).
- Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative to Ground 1, in case Lindmark-I alone was found not to explicitly teach an "array." Lindmark-I teaches the dual-band stacked-patch antenna element, while Lindmark-II explicitly describes arranging seven such elements in a linear array for a base station antenna. For claim 7, which requires operation around 1900 MHz and 2100 MHz, Petitioner argued that Lindmark-I already discloses operation up to 1927 MHz.
- Motivation to Combine: A POSITA would combine the references because Lindmark-II expressly cites Lindmark-I as the source for the antenna element design it arranges into an array. Both references are contemporaneous works by a common author (Björn Lindmark) directed at the same problem. To meet market demand for new cellular frequency bands (like 2100 MHz UMTS), a POSITA would have been motivated to modify the design using well-known frequency scaling techniques to adapt the second patch to the 2100 MHz band.
- Expectation of Success: A POSITA would have a reasonable expectation of success because combining the known element from Lindmark-I into the array taught by Lindmark-II is a simple application of known techniques to achieve a predictable result. Lindmark-II itself confirms the viability of such an array. Frequency scaling was also a routine and predictable technique in antenna design.
Ground 3: Obviousness of Claims 1, 5, and 7 under §103(a)
Prior Art Relied Upon: Snygg (Patent 6,239,750).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner asserted that Snygg teaches or suggests every limitation. Snygg discloses a multiband antenna array with a combination of multiband and mono-band elements, which it describes as a juxtaposition of low-frequency and high-frequency mono-band arrays. The arrangement of stacked-patch elements in Snygg's figures is argued to be virtually identical to that in the ’870 patent. Claim 5 (at least three frequency bands) is taught because Snygg explicitly states its antenna can comprise "any number of stacked elements for different frequencies." Claim 7 is rendered obvious because Snygg discloses operation in bands including 1800-2100 MHz for WCDMA systems.
- Motivation to Combine: This ground does not rely on a combination of references. However, Petitioner argued that if Snygg were found not to explicitly teach that its elements have "similar radiation and impedance patterns," a POSA would have been motivated to design them that way. Achieving matching impedance and radiation patterns is a fundamental design principle for functional multiband antennas, a goal Snygg sought to achieve.
- Expectation of Success: A POSA would know how to modify slot lengths and dielectric layers—as was common in the art—to achieve the desired impedance and radiation patterns with a high expectation of success.
Additional Grounds: Petitioner asserted additional obviousness challenges, including combining Lindmark-I and Lindmark-II with Shapiro (Patent 5,043,738) to teach a triple-band antenna for claim 5, and combining Lindmark-I with Huynh (Patent 5,307,075) as an alternative way to teach an array structure.
4. Key Claim Construction Positions
- "juxtaposition of a plurality of mono-band arrays": Petitioner argued this term is not a manufacturing process but a "conceptual framework" for describing the final positions of antenna elements in an interlaced array. It refers to how the positions are determined by conceptually overlaying mono-band arrays.
- "multiband antenna": Petitioner adopted the definition from the ’870 patent's specification, which requires an antenna element to have "substantially similar" radiation and impedance patterns in multiple frequency bands. Petitioner noted that, in related litigation, the Patent Owner asserted this is met "if the operation of the antenna remained functional."
- "repositioning": Petitioner contended this term does not describe a method step but rather a physical state. The limitation is met by the final position of a single multiband element in an interlaced array where mono-band elements from different conceptual arrays would coincide.
5. Arguments Regarding Discretionary Denial
- Petitioner argued that discretionary denial under §314(a) (based on General Plastic factors) would be inappropriate. The petition asserted this case is distinguishable from precedents where denial was granted because: (1) the ’870 patent had not been the subject of any prior or pending post-grant proceedings; (2) Petitioner Kathrein USA, Inc. is not a party to the related district court litigations; and (3) the petition challenges claims that are not at issue in the district court litigations. Petitioner argued denial would be fundamentally unfair to a first-time filer and non-party to the litigation.
6. Relief Requested
- Petitioner requested that the Board institute an inter partes review and find claims 1, 4, 5, and 7 of the ’870 patent unpatentable and order them canceled.