Allen is a partner in the firm's Chicago office. Since 1993, his practice has concentrated on patent litigation and contested matters. His experience includes first and second chair responsibility in many infringements lawsuits. In litigation, Allen has represented clients in a broad spectrum of technologies, including software, technical systems, business methods, computer process control systems, filtration media, biochemical formulations, complex mechanical systems, and medical devices.

Additionally, Allen is skilled in patent portfolio management, licensing, and counseling. He is also highly experienced in matters pertaining to patent prosecution in the computer, electrical, chemical, biochemical, and mechanical areas.

Allen is the author of several legal publications. He has presented at numerous seminars and conferences, and has held an adjunct faculty position at one of Chicago's law schools. He also lectures for a national patent bar review program. Allen was named an Illinois Super Lawyer for his accomplishments in the field of intellectual property.

Allen holds a B.S. in Chemistry and a B.S. in Chemical Engineering, and a J.D. magna cum laude, all from the University of Illinois. While in school, he served as the Executive Administrative Editor of the University of Illinois Law Review.