PTAB

IPR2019-00950

Kathrein USA Inc v. Fractus SA

Key Events

Petition

petition

Title: Interlaced Multiband Antenna Arrays
Brief Description: The ’870 patent relates to an interlaced multiband antenna array for wireless communications. The technology involves forming the array by the juxtaposition of multiple conceptual mono-band arrays, where multiband antenna elements are used at positions where elements from the different mono-band arrays would otherwise coincide.

Prior Art Relied Upon: Lindmark-I (a 1998 IEEE Aerospace Conference Proceedings paper).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Lindmark-I taught every limitation of claims 1 and 4. Lindmark-I described a dual-band, dual-polarized, stacked-patch antenna element suitable for use in a base-station antenna array. The reference explicitly stated that a base station antenna would have a "linear array of such elements," which Petitioner asserted met the claim requirement for an "interlaced multiband antenna array." Each dual-band element in the array satisfied the "single multiband antenna element" limitation, and the array’s operation in both the GSM (900 MHz) and DCS (1800 MHz) bands satisfied the "plurality of working frequency bands" limitation.
- Key Aspects: The argument centered on the assertion that a linear array comprised entirely of dual-band elements inherently resulted from the "juxtaposition" of two mono-band arrays (one for each frequency band), thus anticipating the claimed structure.

Prior Art Relied Upon: Lindmark-I (1998 IEEE Aerospace Conference Proceedings paper) and Lindmark-II (a 1998 Nordic Radio Symposium paper).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that if Lindmark-I alone was found not to explicitly teach a full array, Lindmark-II remedied this. Lindmark-II, a contemporaneous paper by a common author, expressly taught a linear array of seven antenna elements and explicitly cited Lindmark-I for the design of those elements. For claim 7, which required operation around 1900 MHz and 2100 MHz, Petitioner contended that Lindmark-I already disclosed operation up to 1927 MHz. Modifying the element to also cover the well-known 2100 MHz UMTS band would have been a predictable application of known frequency scaling techniques to meet market demand.
- Motivation to Combine: A POSITA would combine the references because Lindmark-II directly pointed to Lindmark-I for the specific element design to be used in its disclosed array. Both publications addressed the same technical problem of implementing dual-band antennas for base stations.
- Expectation of Success: A POSITA would have had a high expectation of success because the combination involved placing a known, functional element (from Lindmark-I) into a conventional array configuration (taught by Lindmark-II) to achieve the predictable result of a functional multiband antenna array.

Prior Art Relied Upon: Snygg (Patent 6,239,750).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued Snygg taught a multiband antenna array that was virtually identical to the one described in the ’870 patent, including a combination of multiband and mono-band elements formed by juxtaposing high- and low-frequency arrays. For claim 5 (at least three frequency bands), Snygg explicitly stated its design could be extended by stacking additional patches for each new frequency. For claim 7 (1900/2100 MHz), Snygg expressly disclosed operation in the 1800-2100 MHz range, and a POSITA would have found it obvious to select the specific licensed bands of 1900 MHz and 2100 MHz to meet known cellular standards.
- Key Aspects: This ground relied on a single reference that disclosed the core inventive concept. Petitioner asserted that while Snygg did not explicitly state that radiation and impedance patterns were "similar," it would have been obvious for a POSITA to design the antenna to have these characteristics, as this is a fundamental and necessary principle of multiband antenna design.
Additional Grounds: Petitioner asserted further obviousness challenges based on combining Lindmark-I and/or Lindmark-II with Shapiro (to teach a three-band antenna) and combining Lindmark-I with Huynh (as an alternative teaching of a linear array).

"juxtaposition of a plurality of mono-band arrays": Petitioner argued this term was not a manufacturing process but a "conceptual framework" for describing the final positions of antenna elements. The term described how the locations for multiband elements were determined by conceptually overlaying multiple single-band arrays.
"repositioned": Adopting the Patent Owner's position from related litigation, Petitioner argued this term did not describe an action but a resulting physical state. A mono-band element "is repositioned" when it becomes incorporated into a single multiband element at a location where it coincides with an element from another conceptual mono-band array.

Petitioner argued that discretionary denial under the General Plastic factors would be inappropriate. The core reasons provided were that: (1) the ’870 patent had not been subject to any prior or pending post-grant proceedings; (2) Petitioner Kathrein USA, Inc. was not a party to the related district court litigations; and (3) the petition challenged claims that were not at issue in those litigations, making it a distinct matter.

Petitioner requests institution of an inter partes review and cancellation of claims 1, 4, 5, and 7 of the ’870 patent as unpatentable.