In its final ruling last week, the Federal District Court for the Eastern District of Virginia banned Rambus from asserting some of its US patents against Infineon's synchronous dynamic RAM (SDRAM) and double data rate (DDR) SDRAM products.
Rambus said it would appeal against the ruling, adding that the decision "builds upon and adds to a series of reversible errors previously made by the same court".
The lawsuit arises out of patents obtained by Rambus on SDRAM and DDR SDRAM technologies that were being developed by the Joint Electron Device Engineering Council, in which Rambus was participating.
Rambus lost the first round of the lawsuits and was fined $3.5m (£2.5m) for fraud, although the penalty was later reduced to $350,000.
In a related decision last week, a court in California postponed a lawsuit by South Korean chip maker Hynix against Rambus, in which Hynix had sought a declaration that its SDRAM and DDR SDRAM products do not infringe upon Rambus's patents. The court indicated that it was inclined to delay the case until the Infineon lawsuit was resolved.
Along with Infineon and Hynix, Micron Technology also refused to pay Rambus licence fees on the SDRAM and DDR SDRAM patents. Micron and Rambus are fighting a legal battle on the matter before a US District Court in Delaware.