Yisun’s practice focuses on litigation and intellectual property.

Yisun’s practice focuses on all aspects of intellectual property law including patent prosecution, patent litigation and counseling related to electronics, software, e-commerce, business methods, semiconductors and communications.

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

Relevant Experience

  • 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.
  • Appellate and reexamination counsel for NTP, In re NTP, Court of Appeals for the Federal Circuit, on eight separate appeals from the U.S. Patent and Trademark Board of Appeals and Interferences related to eight patent, resulting in reversal of 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 and database management.
  • 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.