Kathrein USA Inc v. Fractus SA

1. Case Identification

• Case #: IPR2019-00956
• Patent #: 9,450,305
• Filed: April 9, 2019
• Petitioner(s): Kathrein USA Inc.
• Patent Owner(s): Fractus, S.A.
• Challenged Claims: 1 and 12

2. Patent Overview

• Title: Slim Triple Band Antenna Array for Cellular Base Stations
• Brief Description: The ’305 patent discloses a slim triple-band antenna array for cellular base stations intended to reduce the physical width of the antenna. The invention purports to integrate multiple cellular services into a compact radiating system by using an antenna array comprising three different sets of radiating elements operating on three distinct frequency bands.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 12 are obvious over Bisiules ’071 in view of Bisiules ’938 and Rhodes.

• Prior Art Relied Upon: Bisiules ’071 (Application # 2004/0252071), Bisiules ’938 (International Publication No. WO 2004/055938), and Rhodes (Application # 2004/0038714).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Bisiules ’071 teaches most limitations of claims 1 and 12, disclosing an antenna array with a layout of radiating elements that is virtually identical to that shown in the ’305 patent. However, Bisiules ’071 does not explicitly teach displacing a second set of radiating elements off the primary vertical axis.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the primary antenna structure of Bisiules ’071 with the teachings of Bisiules ’938 and Rhodes. Bisiules ’938 explicitly teaches arranging radiating elements in offset pairs to enhance beam width control and azimuth steering and to reduce grating lobes. Rhodes teaches the desirability of adjusting beam width and horizontal direction in cellular base stations to add flexibility in allocating capacity and avoiding coverage gaps. A POSITA would thus incorporate the offset element pairs from Bisiules ’938 into the Bisiules ’071 antenna to achieve the enhanced beam control and improved network performance described as desirable by Rhodes.
  • Expectation of Success: A POSITA would have a high expectation of success, as the modification involved applying a known technique (laterally shifting radiating elements) to a known antenna structure to achieve the predictable result of improved beam steering.

Ground 2: Claims 1 and 12 are obvious over Bisiules ’071 in view of Bisiules ’938, Rhodes, and Baliarda.

• Prior Art Relied Upon: Bisiules ’071 (Application # 2004/0252071), Bisiules ’938 (WO 2004/055938), Rhodes (Application # 2004/0038714), and Baliarda (Application # 2002/0171601).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative to Ground 1. Petitioner argued that if the "combination-type assemblies" in Bisiules ’071 were deemed not to teach the claimed "third set of radiating elements" (which operate on two frequency bands), then Baliarda provides the missing teaching. Baliarda explicitly discloses using a single multiband radiating element in positions where elements of separate monoband arrays would otherwise overlap.
  • Motivation to Combine: This ground builds upon the combination in Ground 1. A POSITA would substitute the known multiband elements taught by Baliarda for the combination-type assemblies in Bisiules ’071. This would be a simple substitution of one known component for another to achieve the same multiband functionality, a common design choice for achieving a compact and efficient antenna array.
  • Expectation of Success: Success would be highly predictable, as it involves the mere substitution of one known type of multiband element for another to perform the same function within a similar antenna layout.

Ground 3: Claims 1 and 12 are obvious over Baliarda in view of Bisiules ’938 and Rhodes.

• Prior Art Relied Upon: Baliarda (Application # 2002/0171601), Bisiules ’938 (WO 2004/055938), and Rhodes (Application # 2004/0038714).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Baliarda teaches a triple-band interleaved array that discloses most elements of the challenged claims, including three sets of radiating elements operating in distinct, non-overlapping frequency bands. However, Baliarda does not explicitly show a ground plane for its key antenna array illustration (Fig. 3d) nor does it show radiating elements displaced from the central vertical axis.
  • Motivation to Combine: A POSITA would modify the Baliarda antenna array to include a ground plane, as taught by Bisiules ’938 and common knowledge, to increase performance, improve efficiency, and provide a necessary mounting substrate. Further, a POSITA would combine the Baliarda array with the teachings of Bisiules ’938 and Rhodes to displace pairs of radiating elements off the central axis. This modification would achieve the enhanced beam width and azimuth steering control taught by Bisiules ’938, providing the flexibility to allocate capacity and avoid coverage gaps as desired by Rhodes.
  • Expectation of Success: Adding a ground plane is a standard and expected design element for such antennas. Displacing elements is also a well-known technique with predictable effects on beam control, leading to a high expectation of success.

4. Key Claim Construction Positions

• "frequency band": Petitioner argued this central term should be given its plain and ordinary meaning: "a range of frequencies extending between two limiting frequencies." This construction was asserted to be broader than a construction proposed by the Patent Owner in related litigation ("a range of radio frequencies designated for one or more cellular services"), which Petitioner contended was an improper importation of limitations into the claim term. Petitioner asserted the claims were invalid under either construction.
• "radiating element": Petitioner adopted the construction "element that radiates and/or receives radio waves," consistent with the Patent Owner's position in related litigation and the term's ordinary meaning.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under 35 U.S.C. §325(d), asserting that the petition raised new arguments and prior art combinations not considered during prosecution. It was highlighted that Rhodes was never cited by the Examiner. While Baliarda, Bisiules ’071, and Bisiules ’938 were of record, they were never applied in the combinations asserted in the petition, nor were they the basis for any rejection. Petitioner further contended that the Examiner’s cursory statement regarding Baliarda in the Notice of Allowance was unsupported and erroneous, warranting a fresh review.

6. Relief Requested

• Petitioner requests institution of inter partes review and cancellation of claims 1 and 12 of Patent 9,450,305 as unpatentable.