Yisun’s practice focuses on all aspects of intellectual property law, including patent litigation, portfolio analysis and patent prosecution.

Yisun has particularly extensive experience in patent portfolio analysis, management and counseling. Her subject matter knowledge is wide-ranging, and includes electronics, software, e-commerce, non-fungible tokens (NFT or NFTs), blockchain, crypto, smart contracts, artificial intelligence, business methods, semiconductors and communications.

Yisun is registered to practice before the U.S. Patent & Trademark Office (PTO). Prior to joining the firm, she worked at the PTO as a patent examiner. In this role, Yisun examined patent applications directed to semiconductor lasers and optical fiber devices.

Relevant Experience

  • Represented patent owner in a patent infringement case involving encryption technology.
  • Represented accused infringer before the PTAB and Federal Circuit involving claims-processing rules engine technology.
  • Represented university patent owner in district court and before the Federal Circuit in a patent infringement case involving video scaling technology and high-definition displays.
  • Energy Transportation Group, Inc. v. Sonic Innovations, Inc. et al., (D. Del.) and (Fed. Cir.): Represented patent holder in an infringement matter involving hearing aid patents. The jury returned a verdict for client ETG, finding willful patent infringement, and awarded damages of $31 million against two defendants. The Federal Circuit affirmed the jury’s verdict and the trial court’s post-trial rulings.
  • In re NTP, (Fed. Cir.): Appellate and reexamination counsel for NTP, on eight separate appeals from the Patent Trial and Appeal Board (PTAB) of the PTO and interferences related to eight patents, resulting in reversal of a PTO decision denying seven NTP patents.
  • ePlus vs. SAP AG and SAP America, Inc. (E.D. Va.): Represented patent owner ePlus in infringement action involving electronic procurement systems. Following a four week trial, the case was favorably settled while awaiting the court's decision.
  • Represented major banking and financial services institution in infringement matter involving payment systems and verification techniques. The case was favorably settled following the completion of fact discovery.
  • Prepared and prosecuted patent applications in the electrical arts, including inventions relating to wireless communications, digital signal processing systems, computer network systems, optical telecommunication devices, computer software algorithms, integrated circuit devices and search engines.
  • Prepared and prosecuted patent applications in the financial industry, including inventions relating to card products, check processing, financial algorithms, investment products, healthcare applications, database management, NFTs, blockchain, and crypto analytics.
  • Rendered opinions concerning the infringement, validity and enforceability of patents.
  • Prepared and negotiated intellectual property license agreements.
  • Conducted due diligence review for acquisition of patent portfolios.
  • Participated in complex patent prosecution, including petitions, appeals, re-examinations and reissues.

Awards & Recognition

  • Recommended for Patent Prosecution in Washington, DC (2023) in the IAM Patent 1000, Intellectual Asset Management

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