In Partial Reversal of District Court, CAFC Explains that ‘Hair-Splitting’ is Key to Literal Infringement Analysis

By Eileen McDermott
August 24, 2021

“In a literal infringement case, as we have here, the meaning ascribed to the claims is significant. The burden is on a patent owner to show that ‘the properly construed claim reads on the accused device exactly.’” – CAFC

The U.S. Court of Appeals for the Federal Circuit (CAFC), with Judge Stoll writing, earlier today reversed a denial of judgment as a matter of law (JMOL) of no infringement relating to U.S. Patent No. 9,031,521, which is assigned to Dali Wireless, Inc. The court also affirmed the U.S. District Court of the Northern District of Texas on a number of other issues, including its denial of JMOL of invalidity of the ‘521 patent.

The ‘521 patent is titled “System and Method for Digital Memorized Predistortion for Wireless Communication.” The patent solves the problem of unintended distortions to a signal caused by power amplifiers used to boost the signal on devices such as mobile phones. The patent does this through “through the use of a feedback loop and lookup tables.”

Dali said that CommScope’s FlexWave Prism distributed antenna infringed the ’521 patent. The FlexWave system is installed on telephone poles to extend wireless coverage. The dispute centers on the claim limitation “switching a controller off to disconnect signal representative of the output of the power amplifier.” The district court construed this term to mean “[s]witching a controller to a nonoperating state to disconnect signal representative of the output of the power amplifier,” and CommScope argued that three pieces of prior art anticipated the relevant claims of the ‘521 patent: Wright, Bauder and Khan.

The jury’s verdict awarded damages to both Dali and CommScope and found infringement and no invalidity. The district court then denied both parties’ motion for JMOL and CommScope’s motion for a new trial and attorney’s fees. CommScope appealed and Dali cross-appealed.

In its analysis, the Federal Circuit agreed with CommScope that Dali failed to present evidence proving that the FlexWave meets the district court’s construction of the claim term “switching a controller off” and affirmed the jury’s finding that Wright does not anticipate the challenged claims of the ’521 patent. Dali had argued to the district court that the claim term “switching a controller off” meant “[s]witching a controller to an off status,” and that “off” did not require further definition. CommScope had argued that the claim term in question meant “[s]witching a controller to a nonoperating state,” and the district court agreed. The district court “drew a distinction between: (1) when the controller is turned off and (2) the effect on the system of turning the controller off.” Dali’s defense to this construction was made in a footnote and simply stated that “CommScope’s premise that the controller itself must be turned ‘off’ is . . . literal nonsense.”

The Federal Circuit explained that 1) “an argument that is only made in a footnote of an appellant’s brief is forfeited”; 2) “even if the argument were in the body of the brief, it is insufficiently developed”; and, 3) “most importantly, it is irreconcilable with Dali’s statements in other portions of its brief.”

With regard to the latter point, Dali had asserted elsewhere that the district court’s construction was “unchallenged” and that “[c]laim 1 of the ’521 Patent requires a controller that . . . places itself . . . in a non-operating state”. The Federal Circuit thus adopted the district court’s claim construction and moved on to whether substantial evidence supported the jury’s finding that FlexWave infringes. The court found that Dali presented no evidence showing that (1) the switch itself, (2) the controller itself, or (3) the combination of the switch and the controller are put into a “nonoperating state” in the accused FlexWave, and that in fact there was evidence showing the opposite. Namely, the testimony of CommScope’s expert, Dr. Wood, “who testified that both the switch and the controller are continuously operating in the accused FlexWave,” and which Dali did not contest.

Dali characterized the district court’s distinction as “hair-splitting” and said it was irrelevant to the overall purpose of the invention, but the CAFC said that “in a literal infringement case, as we have here, the meaning ascribed to the claims is significant. The burden is on a patent owner to show that ‘the properly construed claim reads on the accused device exactly.’”

Ultimately, the court felt that Dali’s arguments on invalidity versus infringement were incongruent and highlighted the two arguments side by side.

The court further explained:

This case falls squarely within the principle that a “patent may not, like a nose of wax, be twisted one way to avoid anticipation and another to find infringement .”, Inc. v., Inc., 239 F.3d 1343, 1351 (Fed. Cir. 2001) (cleaned up).

The court thus reversed the district court’s denial of CommScope’s motion for JMOL of no infringement of the ‘521 patent and affirmed the denial of CommScope’s motion for JMOL of invalidity of the ‘521 patent over Wright.


The Author

Eileen McDermott

Eileen McDermott is the Editor-in-Chief of Eileen is a veteran IP and legal journalist, and no stranger to the intellectual property world, having held editorial and managerial positions at several publications and industry organizations. She has acted as editorial consultant for the International Trademark Association (INTA), chiefly overseeing the editorial process for the Association’s twice-monthly newsletter, the INTA Bulletin. Eileen has also served as a freelance editor for the World Intellectual Property Organization (WIPO); as senior consulting editor for the Intellectual Property Owners Association (IPO) from 2015 to 2017; as Managing Editor and Editor-in-Chief at INTA from 2013 to 2016; and was Americas Editor for Managing Intellectual Property magazine from 2007 to 2013.

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  1. Benny August 27, 2021 9:00 am

    It looks to me as though none of the legal experts arguing the case had anything more than the most rudimentary understanding of how the actual patented system works.

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