Background
ParkerVision, Inc. holds patents on technology for down-converting electromagnetic signals in wireless communications — essentially, circuitry used in radio receivers and wireless modems that converts high-frequency signals to lower-frequency baseband signals. The technology is fundamental to wireless devices, and ParkerVision has pursued extensive patent litigation against chipmakers. At issue was U.S. Patent No. 6,091,940 and its construction of the term “storage element” — a key component of ParkerVision’s claimed energy transfer system.
Intel Corp. petitioned for IPR, arguing the ‘940 patent’s claims were obvious. A central dispute was how to construe “storage element”: ParkerVision argued the term referred only to storage elements that are part of an energy transfer system (a narrower reading); Intel argued it referred broadly to any element that stores energy from an input signal. The PTAB adopted Intel’s broader construction, which was different from a construction a parallel district court had applied to the same term. ParkerVision argued on appeal that the PTAB was wrong on the merits and also that Intel had improperly raised new claim construction arguments in its reply brief.
The Court’s Holding
The Federal Circuit affirmed on both issues. On claim construction, the court held that ParkerVision had acted as its own lexicographer — it had defined “storage element” in a patent incorporated by reference into the ‘940 patent, using the phrase “as used herein” followed by an explicit definitional statement. When an inventor defines a claim term in the specification or an incorporated reference with such explicit definitional language, that definition controls over the plain and ordinary meaning, regardless of how a district court may have construed the same term in parallel litigation. The PTAB was bound by that lexicographic definition, not by the district court’s construction.
On the procedural challenge, the court held that Intel’s reply arguments about claim construction were proper under the Administrative Procedure Act (APA). Because ParkerVision first proposed its narrower “energy transfer system” construction in its patent owner response — not in its pre-institution brief — Intel’s reply was the first opportunity for Intel to address that construction. The APA required the PTAB to allow a fair response to new arguments introduced by the patent owner; Intel was not introducing new issues, it was responding to a new issue that ParkerVision had injected. The court emphasized that when a patent owner introduces a new claim construction in its response, the petitioner may respond in the reply without that response being treated as a procedurally improper new theory.
Key Takeaways
- An inventor’s explicit definitional language in a patent (or an incorporated-by-reference patent) controls claim construction — including in IPR proceedings — regardless of conflicting constructions from district courts in parallel litigation.
- The PTAB applies its own claim construction methodology in IPR and is not bound by a district court’s construction of the same term, even when the same patent is being litigated simultaneously.
- If a patent owner introduces a new claim construction argument for the first time in its patent owner response, the petitioner may respond to that construction in its reply without the response being deemed procedurally improper — the APA entitles a party to respond to new issues raised against it.
- Patent owners who use specification language like “as used herein” or “refers to” when defining terms should understand those definitions will apply in IPR proceedings even if a district court adopted a different construction.
Why It Matters
ParkerVision v. Vidal highlights the ongoing divergence between district court and PTAB claim constructions — a phenomenon that complicates parallel patent litigation. Companies that litigate patents simultaneously in district court and before the PTAB often find that the two forums adopt different constructions, and each forum will reach its own conclusions independently. For patent holders, the decision underscores the danger of specification language that explicitly defines claim terms: if you wrote “as used herein, X means Y” in your patent, an IPR petitioner will hold you to that definition even if a district court was persuaded to adopt a broader construction. For IPR practitioners, the case confirms the proper scope of reply briefing when patent owners raise new arguments in their patent owner responses.