Diana M. Sangalli, P.C.


  • Diana M. Sangalli, P.C.
  • Phone: +1 512 277 2250
    Fax: +1 713 583 2836

    Import to Address Book

  • Duane Morris LLP
    Las Cimas IV
    900 S. Capital of Texas Hwy, Suite 300
    Austin, TX 78746-5435

Diana M. Sangalli, P.C. has practiced in the area of intellectual property law for more than two decades, with a focus on intellectual property litigation and patent preparation and prosecution.

In her litigation practice, Ms. Sangalli has represented clients in patent infringement and trade secret matters related to a range of diverse technologies, including optical disc recognition, wireless LANs, telecommunications networks, webpage authentication, offshore platforms and medical devices. She has appeared in district courts throughout the country, taking the lead at claim construction hearings and cross-examining technical experts at trial. Ms. Sangalli’s experience in litigation matters extends to appellate proceedings, including brief writing and oral arguments before the Court of Appeals for the Federal Circuit and the Court of Appeals for the Sixth Circuit. She also has represented clients in litigation involving commercial disputes, breach of contract and product liability causes of action.

In addition, Ms. Sangalli has extensive experience preparing and prosecuting patent applications covering a variety of electrical, mechanical and computer-related technologies for small, medium and large-sized corporations in the oil and gas, computer, temperature instrumentation, semiconductor and consumer product industries. Representative subject matter includes wireless communication networks and protocols, fiber optic temperature and vibration sensing systems, temperature sensing devices used in the petrochemical industry, seismic surveying systems, and downhole tools for hydrocarbon wells. Her prosecution and litigation skills have also been applied in multiple inter partes review proceedings before the Patent and Trademark Appeal Board.

Prior to entering the practice of law, Ms. Sangalli spent almost a decade working as a research and development engineer at Hughes Aircraft Co. and Sigmapower, Inc. in California, where she designed battery charging circuitry and complex high-voltage power supply systems used in satellite communication networks, shipboard phased array radar installations and missile guidance systems.

Ms. Sangalli is a 1995 magna cum laude graduate of the University of Illinois College of Law, where she was editor-in-chief of the University of Illinois Law Review, and a graduate of the University of Illinois at Urbana-Champaign (B.S.E.E.)

Representative Matters


  • Argued before the U.S. Court of Appeals for the Federal Circuit on behalf of an American multinational telecommunications corporation and obtained an affirmance of summary judgment of invalidity of a software patent with computer-implemented means-plus-function claim limitations because the patent failed to disclose corresponding algorithms.
  • Argued before the U.S. Court of Appeals for the Sixth Circuit on behalf of a multinational medical device corporation regarding a supplier’s breach of a patent infringement indemnification agreement.
  • Obtained from the U.S. Court of Appeals for the Federal Circuit on behalf of a medical device corporation affirmance of summary judgment of non-infringement based on a favorable claim construction.
  • Counsel for a medical device corporation in patent infringement action against a competitor that is currently pending in district court.
  • Defense counsel for multinational telecommunications corporation in multiple patent infringement matters throughout the U.S., resulting in settlements that the client found favorable.
  • Defense counsel in patent litigation relating to wireless data networks. Won significant Markman decision resulting in entry of judgment of non-infringement that was affirmed by the Federal Circuit.
  • Defense counsel for foreign manufacturer of motorcycle grips in patent litigation matter. Settled case on terms client found favorable after significant deposition of the patent owner and inventor.
  • Other Matters

  • Counsel in multiple Inter Partes Review proceedings.
  • Counsel to a precision temperature sensor design and manufacturing company with respect to all intellectual property matters, including building a patent portfolio and negotiating license agreements.
  • Counsel to major oil and gas company in obtaining patents.
  • Counsel to a medical device company with respect to due diligence matters, opinions and patent prosecution.

Areas of Practice

  • Intellectual Property
  • Patents


  • Texas
  • U.S. District Court for the Eastern District of Texas
  • U.S. District Court for the Southern District of Texas
  • U.S. District Court for the Western District of Texas
  • U.S. District Court for the Northern District of Texas
  • U.S. Court of Appeals for the Federal Circuit
  • U.S. Patent and Trademark Office


  • University of Illinois College of Law, J.D., magna cum laude, 1995
    - Editor in chief, University of Illinois Law Review
  • University of Illinois at Urbana-Champaign, B.S., Electrical Engineering, 1983


  • Duane Morris LLP
    - Partner, 2014-present
    - Special Counsel, 2011-2013
  • Trop, Pruner & Hu, P.C.
    - Shareholder, 2004-2011
  • Holman, Keeling & York, P.C.
    - Associate, 2003-2004
  • Fulbright & Jaworski LLP
    - Counsel, 2001-2003
  • Fletcher, Yoder & Van Someren
    - Associate, 1999-2001
  • Foley & Lardner
    - Associate, 1995-1998
  • Sigmapower, Inc.
    - Senior Design Engineer / Manager of Engineering Projects, 1987-1992
  • Hughes Aircraft Co.
    - Member of Technical Staff, 1983-1987

Selected Publications

  • Co-author, "When Is a Warning Necessary? Common Law Exceptions to the Duty to Warn," 15th Annual Products Liability Conference, University of Wisconsin Engineering Department, November 2003