10 F.4th 1289
Fed. Cir.2021Background
- CommScope sued Dali; Dali counterclaimed asserting U.S. Patent No. 9,031,521 (the ’521 patent) for a digital predistortion system; a jury found the accused CommScope FlexWave system infringed and the patent not invalid.
- The ’521 patent claims a training phase that builds lookup-table predistortion values and an operating phase that requires “switching a controller off to disconnect signal representative of the output of the power amplifier.”
- The accused FlexWave uses two power amplifiers and a selector switch that continuously chooses feedback from one amplifier or the other to compute predistortion.
- The district court construed the disputed claim term to require switching the controller to a "nonoperating state" so as to disconnect the amplifier output signal.
- At trial Dali’s expert testified the FlexWave “turns the feedback off,” but did not show the controller itself becomes nonoperating; CommScope’s expert testified the switch and controller remain continuously operating.
- The Federal Circuit held there was not substantial evidence of literal infringement under the district court’s construction, reversed the denial of JMOL of no infringement as to the ’521 patent, and affirmed the district court in all other respects (including denying JMOL of invalidity).
Issues
| Issue | Plaintiff's Argument (Dali) | Defendant's Argument (CommScope) | Held |
|---|---|---|---|
| Construction of “switching a controller off” | Means simply switching controller to an “off” status; no further gloss needed | Means switching the controller to a nonoperating state that disconnects the amplifier output | Court adopted district court construction: requires putting the controller itself into a nonoperating state |
| Literal infringement of claim 1 by FlexWave | FlexWave meets the limitation because its controller/switching operation "turns the feedback off" for a given amplifier | No evidence that the controller or switch is put into a nonoperating state; FlexWave’s selector continuously operates | Reversed: no substantial evidence of literal infringement under the proper construction (JMOL of no infringement granted) |
| Anticipation by Wright (prior art) | Wright’s multiplexer does not disclose putting the controller into a nonoperating state | Wright’s MUX functions like FlexWave’s selector; similar operation when N=2 | Court left jury’s no-anticipation verdict undisturbed because the nonoperating-state requirement influenced both infringement and anticipation analyses |
Key Cases Cited
- Peters v. Active Mfg. Co., 129 U.S. 530 (establishes that a later device that infringes, if earlier, would anticipate)
- Liebel‑Flarsheim Co. v. Medrad, Inc., 481 F.3d 1371 (anticipation requires a prior-art reference to disclose every claim limitation)
- O2 Micro Int’l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351 (claim construction may require clarifying what a term does to the system)
- ACCO Brands, Inc. v. ABA Locks Mfr. Co., 501 F.3d 1307 (standard of review: infringement tried to a jury reviewed for substantial evidence)
- Engel Indus., Inc. v. Lockformer Co., 96 F.3d 1398 (patent owner must prove the properly construed claim reads on the accused device exactly in a literal-infringement case)
- Rembrandt Wireless Techs., LP v. Samsung Elecs. Co., 853 F.3d 1370 (JMOL review under regional-circuit law; Fifth Circuit standard cited)