Federal Circuit Upholds PTAB Claim Construction Conflicting with Parallel District Court Proceedings

On December 15, the U.S. Court of Appeals for the Federal Circuit (CAFC) issued a precedential decision in ParkerVision, Inc. v. Vidal affirming the Patent Trial and Appeal Board’s (PTAB) invalidation of ParkerVision’s patent claim to down-converting electromagnetic (EM) signals in wireless communication networks. In so holding, the Federal Circuit upheld the PTAB’s use of claim construction conflicting with parallel proceedings in the Western District of Texas on the grounds that the patentee defined the term “storage element” as a lexicographer.

PTAB: ‘Storage Element’ Not Limited to Energy Transfer Systems, Holds Non-Negligible Energy

At issue on appeal is claim 3 of U.S. Patent No. 7110444, Wireless Local Area Network (WLAN) Using Universal Frequency Translation Technology Including Multi-Phase Embodiments and Circuit Implementations. Intel petitioned for inter partes review (IPR) proceedings on the ‘444 patent in July 2020, four months after ParkerVision asserted the ‘444 patent against Intel in Western Texas. Claim 3 is directed to modules for down-converting wireless signals so voice information within the signal can be transmitted audibly.

During inter partes review (IPR) proceedings, ParkerVision and Intel disputed the meaning of the claim term “storage element,” which, along with a switch, both comprise the claimed first and second frequency down-conversion modules. At the PTAB and on appeal, both ParkerVision and Intel agreed that the ‘444 patent incorporated by reference another ParkerVision patent including a critical paragraph within the written description defining “storage modules and storage capacitances” as “refer[ring] to systems that store non-negligible amounts of energy from an input EM signal.”

In contrast to claim construction in the Western District of Texas, the PTAB adopted a construction of “storage element” proffered by Intel that did not restrict the claim term’s meaning to an energy transfer system. The incorporated ParkerVision patent describes two types of down-conversion systems: energy transfer systems, which store input EM signals without regard for accurately reproducing their voltage; and under-sampling systems, in which the holding capacitance storing the input EM signal’s voltage does not significantly discharge between pulses of an under-sampling signal. The PTAB nixed ParkerVision’s construction, which restricted “storage element” to energy transfer systems, after finding that ParkerVision acted as its own lexicographer in the incorporated patent reference by defining storage modules and capacitances as storing energy.

CAFC: ParkerVision Intended to Define Claim Term in Incorporated Patent Reference

In reviewing the critical paragraph from the incorporated ParkerVision patent, the Federal Circuit agreed that ParkerVision intended to act as its own lexicographer in defining the disputed claim term. The paragraph’s use of the phrase “as used herein” indicated that the definitions of storage modules and capacitances were meant to apply throughout the patent. The use of “refer to” language evidenced further intent for the patentee to be definitional.

While ParkerVision argued that the offered definition was supposed to be comparative to the definition for holding modules and capacitances also contained within the paragraph, the Federal Circuit noted that the sentence could be both comparative and definitional. While ParkerVision’s construction was adopted in the Western Texas litigation, the Federal Circuit found analysis by the magistrate judge and the special master were unduly influenced by energy transfer systems in the incorporated patent’s written description.

ParkerVision also raised an unsuccessful Administrative Procedures Act challenge to the PTAB’s adoption of Intel’s argument raised on petitioner’s reply that an asserted prior art reference taught capacitors storing non-negligible amounts of energy from an input EM signal. Noting that the PTAB’s decision to institute Intel’s IPR did not provide an express claim construction, the Federal Circuit likened the present appeal to issues raised in Axonics v. Medtronic (2023). In Axonics, the Federal Circuit reversed the PTAB after finding that it failed to give an IPR petitioner the opportunity to present invalidity evidence in response to a new claim construction offered by the patent owner. Because ParkerVision offered a new claim construction for “storage element” following the PTAB’s institution decision, the Board was obligated under Axonics to consider Intel’s new prior art arguments raised in its reply.

Finally, the appellate court also nixed ParkerVision’s appeal to the PTAB’s exclusion of sur-reply arguments on the amount of energy stored by the prior art’s capacitors, as well as the Board’s finding that elements of the prior art store non-negligible amounts of energy. ParkerVision’s sur-reply focused on the “storage element” requirements and not the prior art’s failure to teach those limitations, thus the Federal Circuit ruled that the PTAB properly treated ParkerVision’s argument as a new theory of patentability that it didn’t need to consider. The PTAB also found substantial evidence supporting the Board’s obviousness ruling, holding that ParkerVision’s arguments reiterated its flawed energy transfer requirement and sur-reply procedural challenges.