Signal Tech [NPE] filed three separate suits against Analog Devices, Linear Technology, and Maxim Integrated Products, alleging that the defendants’ amplifiers infringe a patent related to low voltage switchable Gm cells.  These are the first patent infringement suits filed by Signal Tech.  The patent-in-suit was one of 20+ patents marketed by IP Harbor on behalf of Infineon in 2010. RPX reviewed the  in June 2010 as open market opportunity “Infineon HDD”.  Current USPTO assignment records still reflect Infineon as the assignee. 11/2, District of Delaware, 1:2011cv01073; 1:2011cv01074; 1:2011cv01075.