Stephanie P. Koh

STEPHANIE KOH serves as co-leader of Sidley’s global IP Litigation practice. Stephanie focuses on complex patent litigation and has achieved substantial trial success on behalf of some of the world’s most sophisticated organizations. She has represented clients in both offensive and defensive postures in cases involving a wide variety of technologies, including pharmaceuticals, medical devices, power converters, and communications systems.

“Stephanie is an outstanding trial lawyer. She is a fierce advocate and couples that with a steady and genial demeanor, making her a pleasure to work with.”
Chambers USA 2025

Stephanie frequently leads case teams and argues high-stakes dispositive motions that have led to countless victories for her clients. Leveraging her training in chemical engineering, Stephanie is well-positioned to quickly establish in-depth understanding of technologies involved in her clients’ businesses and is thus a fierce advocate in the courtroom.

“[Stephanie] has fantastic intellect, grasps multifaceted problems, and distills them down to easy-to-understand discussions and identifies solutions.”
Chambers USA 2024

Advocacy on behalf of her clients has earned Stephanie acknowledgement in a variety of publications, including:

• The Best Lawyers in America®, Litigation — Intellectual Property (2026)
• Chambers USA: Illinois — Intellectual Property (2023–2025)
• Crain’s Chicago Business’ 2023 “Notable Women in STEM” 
• IAM Patent 1000 (2022–2025)
• Managing IP
  • “Top 250 Women in IP Litigation” (2024)
  • “Litigator of the Year – Illinois” (2024); Shortlisted for “Litigator of the Year – Illinois” (2025)
  • “Illinois Patent Star” (2021–2025)

Representative cases include:

ABS Global Inc. and Genius PLC.

• Inguran, et al. v. ABS Global, Inc., Genus PLC v. Inguran (W.D. Wis.) — Represented Genus plc and ABS Global, Inc. in multiple antitrust and patent suits involving bovine sexed-semen technology. Before a global settlement was reached in 2024, helped secure multiple favorable trial and pre-trial rulings, and an appellate win that invalidated claims of a key patent asserted against ABS. (2019–2024)

Peddinghaus

• Ficep Corp. v. Peddinghaus Corp. (D. Del.) — Prevailed as lead lawyer in obtaining summary judgment in favor of Peddinghaus in a patent infringement case regarding automation in manufacturing processes brought by competitor Ficep. Following oral argument, the court granted Peddinghaus’ motion for summary judgment that all claims of Ficep’s lone asserted patent are invalid for claiming patent ineligible subject matter. That judgment was upheld on appeal. (Judgment 2/28/2022; Appeal 8/21/2023)

Magna

• Panasonic Corporation v. Magna International, Inc. (W.D.TX) — Counsel for Magna in competitor suit involving patents on radar and camera systems in vehicles. Defeated multiple indefiniteness challenges regarding Magna’s counterclaim patents. (2022–2024) 
• Magna Mirrors of America v. SMR (W.D. MI) — Counsel for Magna in a patent suit against a competitor relating to rearview mirror systems that reduce the driver’s blind spot. Defeated institution of SMR’s 10 petitions for inter partes review of Magna’s patents. Prevailed on all claim construction issues, and obtained summary judgment of infringement. Prevailed as first-chair in bench trial regarding inequitable conduct allegations. (2017–2022)
• Wildcat Licensing v. Magna International, Inc. et al. (D. Del.) — Counsel for Magna in a patent suit directed to manufacturing methods and assembly systems. After IPRs were filed against both of Wildcat’s asserted patents, the patents were determined to be invalid. Wildcat appealed the PTAB’s decisions to the Federal Circuit and, on January 1, 2024, the Federal Circuit affirmed across the board. Wildcat sought panel rehearing or rehearing en banc, and the Federal Circuit denied that request on March 26, 2024. The district court case was then dismissed with prejudice following the invalidation of Wildcat’s patents and the victory at the Federal Circuit. (2021–2024) 

Calamp Corp.

• Omega v. CalAmp (M.D. Fla) — Represented CalAmp in retrial after obtaining remand on appeal. Obtained a jury verdict of no induced infringement and, therefore, no liability on two patents and no willful infringement on any patent. One patent that was found to be valid and infringed in first trial (where Sidley was not counsel) was found by the jury to only have one infringing unit and damages of $1.00. One patent that was found to be infringed had damages reduced to $5/unit. Previous award, which included treble damages and attorneys’ fees and totaled more than US$20 million, reduced to US$4.6 million. In a further appeal, the case was remanded yet again for a new trial on damages, and the case then settled favorably. (2019–2022)
• ORBCOMM v. CalAmp (E.D. Va) — Represented CalAmp in five-patent suit directed at systems for tracking, monitoring, and controlling remote assets. Invalidated one patent on 101 grounds, obtained voluntary stipulations of dismissal with prejudice on three additional patents, and obtained a stipulation of non-infringement regarding the one remaining patent following claim construction. The case, along with an affirmative case CalAmp brought accusing ORBCOMM of infringing two of CalAmp’s patents, settled and was dismissed in May 2017.

Aircell, Inc. and Gogo, Llc

• SmartSky Networks, LLC v. Gogo Business Aviation, LLC (Fed. Cir.) – Prevailed as lead lawyer in securing denial of preliminary injunction and affirmance of that denial on appeal in patent litigation involving air-to-ground communications. (2022–2024)
• Ambit v. Aircell (D. Mass.) — Prevailed as second-chair counsel for Defendants Aircell and Delta Air Lines in a three-week jury trial before Judge Young; plaintiff alleged that Aircell’s Gogo® inflight internet service infringes plaintiff’s patent; the jury found no infringement and all patent claims invalid for anticipation, obviousness, lack of enablement, and insufficient written description. (Verdict 07/28/10)
• Advanced Media Networks v. Gogo, Aircell, Delta Air Lines, et al. (C.D. Cal.) — Counsel for Gogo and all other defendants for alleged patent infringement directed at the Gogo® inflight internet service. Obtained favorable Markman ruling on 6/14/2013 leading to settlement. 

Allstate

• ATOS, LLC v. Allstate Insurance Company (N.D. IL.) — Lead counsel for Allstate in case involving claims of patent infringement and trade secret misappropriation. In granting, in part, Allstate’s motion to dismiss, the district court invalidated all three asserted patents on Section 101 grounds. In parallel IPR proceedings, also independently invalidated nearly all asserted claims of the three asserted patents on prior art grounds. RideMetric appealed the adverse decisions from the IPRs to the Federal Circuit. Allstate prevailed in two of those appeals and the third remains pending. (2022–2024)

Microsoft

• InterDigital Comm. Inc. et al v. Nokia Corp. et al. (D. Del.) — Represented Nokia Inc. and Microsoft Mobile Oy in patent infringement case involving Nokia mobile phones and Microsoft tablets. (2015)
• Zix Corp. v. Echoworx Corp. (E.D. Tex.) — Represented Microsoft in a patent infringement case defending against third-party complaint filed by Echoworx. Successfully obtained early dismissal of Microsoft on a motion to dismiss. (2015–2016)
• Dynamic Data v. Microsoft (E.D. Tex.) — Represented Microsoft in a patent infringement case involving 13 patents relating to video processing technology. Case was resolved and dismissed in 2019.

Owens Corning

• Fast Felt v. Owens Corning (N.D. Ohio) — Represented Owens Corning in a patent infringement suit directed at Owens Corning’s SureNail® roofing shingles and the process for making them. After prevailing at a Markman hearing in the district court, prevailed in the Federal Circuit on an appeal of an IPR ruling, which resulted in the asserted patent being invalidated. District court case was then dismissed. (2017)
• CertainTeed v. Owens Corning (D. Del.) — Counsel for Owens Corning in a patent infringement suit involving five patents directed at laminated shingles. Patents all invalidated in IPRs. (2016)  

SynQor, Inc.

• SynQor, Inc. v. Vicor Corporation (E.D. Tex.) – Secured a jury win in a patent infringement case SynQor brought against Vicor. The court then found that the case was exceptional based both on willful infringement and litigation misconduct by the defendant and awarded enhanced damages, attorneys’ fees, pre- and post-judgment interest, and costs. Vicor has appealed to the Federal Circuit. (2011-2024)
• SynQor, Inc. v. Artesyn Technologies, Inc., et al.(E.D. Tex.) — Represented SynQor in patent infringement action against 11 of the largest suppliers of DC-DC power converters. Successes included:
  • Prevailed as part of the in-court trial team before a jury in Marshall, Texas. The jury ruled for SynQor on each of its patent infringement claims and awarded SynQor the entirety of what it sought from each of the eleven defendants. In total, SynQor was awarded more than US$95 million, which included lost profits and price erosion damages. (Jury Verdict 12/21/10) 
  • Prevailed as part of an in-court team in obtaining a permanent injunction after a two-day evidentiary hearing directed at whether and when a permanent injunction should issue. In granting an immediately effective permanent injunction, the U.S. district court rejected the defendants’ request for a lengthy transition period in which they could continue to sell the infringing products to certain end-customers, including Cisco Systems, Inc. (2011 WL 238645 (E.D. Tex., January 24, 2011)) 
  • Obtained supplemental damages and sanctions against certain defendants for infringing sales not included in the jury verdict. (2011 WL 2683181 and 2011 WL 2683184 (E.D. Tex., July 11, 2011)) 
  • Final judgment affirmed in full by the Federal Circuit. (March 13, 2013) Petitions for en banc review and to stay the mandate were denied in May and June 2013. 
• SynQor, Inc. v. Artesyn (E.D. Tex.) — Trial counsel for SynQor in a four-day bench trial against some of the defendants in the earlier case for continuing to induce infringement after the entry of a permanent injunction and for allegedly violating the permanent injunction. Established liability and obtained additional damages; case settled on appeal in November 2015. 
• Lineage Power Corp. v. SynQor, Inc. (E.D. Tex.) — Represented SynQor in patent infringement action involving nine patents relating to power converters; case settled on favorable terms. (August, 2011) 
• SynQor, Inc. v. Ericsson, et al. (E.D. Tex.) — Represented SynQor in a patent infringement action involving same patents asserted in Artesyn case; settled with Ericsson on favorable terms on the eve of the preliminary injunction hearing; settled with Cisco on eve of trial in November 2015.

Merck

• Merck Sharp & Dohme Corp. v. Actavis (D. NJ) — Counsel for Merck in Hatch-Waxman case directed at the antibiotic Dificid®. Case settled in 2021.

Johnson & Johnson

• Ethicon Endo-Surgery, Inc. v. Crescendo Technologies, LLC. (S.D. Ohio) — Represented Ethicon in a dispute over the ownership of patent applications relating to ultrasonic shears. Case concluded with a favorable result for Ethicon following a 10-day jury trial. (2009) 
• Boston Scientific Corp. and Target Therapeutics, Inc. v. Cordis Corp. (N.D. Cal.) — Represented Cordis in a patent case involving medical devices for the endovascular treatment of aneurysms and vascular malformations; favorably settled on the eve of trial. (2002–2009) 
• Ethicon Endosurgery, Inc. — Represented Ethicon in arbitration over a patent infringement claim relating to a medical device. (2006)
• Applied Medical Resources Corp. v. Ethicon Endo-Surgery, Inc. (C.D. Cal.) — Represented Ethicon in a patent case involving three sets of medical device patents; favorably settled on the eve of trial. (2005)  

National Pasteurized Eggs, Inc.

• National Pasteurized Eggs, Inc. et. al. v. Michael Foods, Inc. et. al. (W.D. Wis.) — Trial counsel for National in patent infringement suit involving three of National’s and three of Michael Foods’ patents, all directed at the in-shell pasteurization of eggs. The jury found each of National’s patents to be infringed and not invalid, and invalidated all of Michael Foods’ patents on written description and enablement grounds. The jury awarded approximately US$6 million in damages. Following the verdict, the court entered a permanent injunction on 6/19/2012 and denied all post-trial challenges on 3/29/13. The case settled while on appeal.