Warren K. Mabey Jr.

I'll research this attorney's professional background before writing the summary.

Let me dig deeper into the tracked cases and PTAB experience.

Warren K. Mabey Jr. — Patent Litigation Summary

Focus areas. Mabey's practice centers on patent litigation in electrical engineering and computer science, with a technology range running from semiconductor chips and power converters to routers, chargers, and consumer electronics. His tracked matters involve FPGA/microprocessor architecture (the Sentient Sensors v. Xilinx dispute over U.S. Patent 6,938,177), enterprise and computer-science patents asserted against FedEx (Valtrus Innovations), and Delaware-district semiconductor and power-management cases such as ON Semiconductor v. Power Integrations and Delta Electronics v. Vicor. He has also worked ITC Section 337 matters, including a robot-vacuum investigation for iRobot. His firm bio lists litigation, ITC litigation, and patent litigation as his practice areas; nothing in the record indicates a pharma or life-sciences patent docket.

Side preference. He is overwhelmingly a defense-side litigator for operating companies. Of the five tracked appearances, four are for defendants; the single plaintiff-side entry is as local counsel for Xilinx in the parallel IPR (i.e., representing a petitioner, not a patent owner asserting claims). The pattern is defending technology companies against NPE/PAE infringement suits — Xilinx/AMD/ATI in the Sentient Sensors litigation and FedEx in the Valtrus campaign.

Firm context and notable matters. Mabey has been at Fish & Richardson throughout his tracked career, based in the firm's Wilmington, Delaware office, where he is a principal and serves as the office's recruiting principal. He rejoined Fish in 2017 after clerking on the Federal Circuit; he was elevated to principal effective January 1, 2018. His most prominent tracked case is Valtrus Innovations Ltd. v. FedEx Corp. (E.D. Tex.), where he is lead counsel for FedEx against a multi-patent computer-science assertion; FedEx filed a series of IPRs (IPR2025-01490, -01491, IPR2026-00039, -00060), several of which drew discretionary denial. In the Sentient Sensors v. Xilinx matter he served as lead counsel on the district court defense and as local counsel on the petitioners' side of the IPR; the Board's adverse ruling to the patent owner was affirmed by the Federal Circuit in a Rule 36 judgment in April 2026 (appellate argument handled by other Fish counsel).

PTAB / IPR experience. He appears in post-grant proceedings, but in the tracked record his role is that of Delaware/local counsel supporting the petitioners' team rather than lead petitioner counsel; the substantive IPR advocacy in these matters was handled by other Fish attorneys.

Bar and education. Martindale lists admissions in Pennsylvania and New Jersey (2010) and Delaware (2012); his firm bio notes J.D. summa cum laude, Rutgers Law School–Camden (2010), and a B.S. in electrical engineering from Bucknell (2004), plus clerkships with Judge Raymond T. Chen (Fed. Cir., 2016–17) and Judge Joseph H. Rodriguez (D.N.J., 2010–11). His current bar standing in each jurisdiction was not independently confirmed beyond these directory listings.