Addressing a Patent Trial and Appeal Board (PTAB) unpatentability decision that turned on claim construction, the US Court of Appeals for the Federal Circuit explained that the broadest reasonable interpretation of a claim term cannot be so broad that it is inconsistent with the specification or renders the term meaningless. In re: Power Integrations, Inc., Case No. 17-1304 (Fed. Cir., Mar. 19, 2018) (Mayer, J).

In 2006, Fairchild, Inc., requested ex parte re-examination of a Power Integrations patent directed to a digital frequency jittering circuit. In a first decision finding the claims invalid, the PTAB rejected Power Integrations’ argument that the term “coupled” in the challenged claims requires two components to be connected “such that voltage, current or control signals pass from one to another.” Instead, the PTAB adopted a broader construction of “coupled” based upon a generalist dictionary where any two components in the same circuit were considered to be “coupled.” Power Integrations appealed, and the Federal Circuit vacated the PTAB’s decision, explaining that the PTAB had an obligation to consider whether Power Integrations’ construction, which had been adopted by a district court in parallel litigation, was consistent with the broadest reasonable construction. On remand, the PTAB again found the challenged claims invalid, concluding that comparison of its claim construction with the district court’s construction was unwarranted because a district court construction of a term is typically narrower than the broadest reasonable construction of that term. Power Integrations again appealed.

On appeal, the Federal Circuit found that the PTAB’s claim construction was unreasonably broad and improperly omitted any consideration of the specification. The Court contrasted Power Integrations’ construction of “coupled,” which required a specific control relationship, with the PTAB’s construction, which allowed for any two elements in the same circuit. The Court found that the plain language of the claim required a causal relationship between the two coupled elements, while the PTAB’s construction would allow for significant intervening components. In addition, the Court found that the PTAB’s construction rendered the claim term “coupled” meaningless, because the claim already recited that the two elements were in the same circuit. The Court also found that the PTAB’s construction was inconsistent with the specification, which teaches the elimination of superfluous components and shows two coupled components connected in a manner consistent with Power Integrations’ construction such that voltage, current or control signals pass from one to another. The Court concluded that Power Integrations’ construction of “coupled” comports with the broadest reasonable construction of the term, and based on that construction, the Court reversed the PTAB’s decision affirming the examiner’s rejections.