Rambus announced it has filed a patent infringement suit in the US District Court for the Northern District of California. In the suit, Rambus charges that DDR2, GDDR2 and GDDR3 memory devices from Hynix Semiconductor, Infineon Technologies, Inotera Memories and Nanya Technology Corporation use Rambus’ patented inventions.

The Los Altos, California-based firm is asserting that DRAM manufacturers Hynix Semiconductor, Infineon Technologies, Inotera Memories and Nanya infringe up to 18 of its patents with DDR2, GDDR2 and GDDR3 devices that are currently shipping in the marketplace.

“With analyst firms projecting a rapid transition this year from DDR to DDR2 and GDDR, and with strong evidence of infringement of our patents already in the public record, we have taken this step today, filing our first new patent case in the US since August 2000. Our preference is to work with the semiconductor industry to provide value and resolve these issues through other means. But sometimes we – like other patent holders - must rely on the court system to be fairly compensated for our inventions,” said John Danforth, senior vice president and general counsel at Rambus.

To get licensing fees from DRAM makers Rambus is continuously trying to prove that the key-technologies used in SDRAM and DDR SDRAM memory types were originally developed by Rambus. While some companies pay the fees now, some others, including Micron, Hynix, Infineon do not pay royalties to Rambus.