The Patent Trial and Appeal Board has found that an Entropic Communications LLC television receiver patent challenged by Comcast is invalid, about a month after the board found that claims in two other patents were also unpatentable.

In a Monday decision, the PTAB ruled in favor of Comcast in its challenge to all 20 of the claims in U.S. Patent No. 9,210,362.

The board said that half the claims were invalid as both obvious and anticipated over an earlier patent application called Zhang that relates to digital circuitry, saying that piece of prior art alone covered the elements of those claims.

As for the other claims of the '362 patent, they were invalid in light of Zhang in combination with additional prior art, including an earlier patent, a communications magazine article and two other patent applications.

Monday's decision comes after two other decisions from early September where the PTAB ruled on two other communications network patents owned by Entropic.

In one of those final written decisions in an inter partes review, the board agreed with Comcast that all 18 claims of Entropic's U.S. Patent No. 8,792,008 were invalid as obvious.

In the second decision, the board found that Comcast had shown that 16 claims of another patent — U.S. Patent No. 8,284,690 — are invalid as anticipated or obvious, but it upheld eight other claims.

Entropic has accused Comcast and Cox Communications of infringing these patents and others in separate suits in the Central District of California. The judge has agreed to stay the Comcast case until the PTAB proceedings are over, but Cox did not agree to be bound by estoppel provisions that are applicable to Comcast, so its case remains active.

Entropic has asserted the two patents-at-issue in the decisions against several other TV companies in cases that have been resolved, including Charter Communications, DirecTV and Dish Network, according to the PTAB documents. The board has noted that Comcast also has challenged numerous other Entropic patents at the board.

In recent months, Deputy U.S. Patent and Trademark Office Director Coke Morgan Stewart has denied many of Comcast's petitions, citing the fact that the company filed multiple petitions on the same Entropic patents.

Counsel for the parties did not immediately respond to requests for comment from Law360 on Tuesday.

The patent-at-issue is U.S. Patent No. 9,210,362.

Administrative Patent Judges Michelle N. Wormmeester, Jon M. Jurgovan and Frederick C. Laney sat on the panel.

Comcast is represented by Frederic Meeker, Michael S. Cuviello, Harry W. Porter, Paul T. Qualey and Joshua L. Davenport of Banner & Witcoff Ltd.

Entropic is represented by Jason A. Engel, Erik J. Halverson, Kyle M. Kantarek and Nolan R. Hubbard of K&L Gates LLP and Kenneth J. Weatherwax, Parham Hendifar and Nathan Lowenstein of Lowenstein & Weatherwax LLP.

The case is Comcast Cable Communications LLC v. Entropic Communications LLC, case number IPR2024-00432, before the Patent Trial and Appeal Board.