US 10877233

US patent 10877233, titled "Active ethernet cable with preset pre-equalization," was filed on November 27, 2019, and issued on December 29, 2020. The patent is assigned to Credo Technology Group Ltd. The inventors are Yifei Dai, Yattung Lam, and Rajan Pai.

Abstract:
The patent describes a cable, a manufacturing method, and a communications method that utilize preset transmit-side equalization to enhance performance and/or reduce receiver-side equalization needs. An exemplary cable includes first and second data recovery and re-modulation (DRR) devices that exchange multi-lane data streams with host interface ports via end connector plugs. Electrical conductors connect these DRR devices to convey electrical transit signals. Both DRR devices convert between these electrical transit signals and the multi-lane data streams for their respective host interface ports, providing pre-equalization of the electrical transit signals using transmit filter coefficient values stored in nonvolatile memories.

Plain-language overview of independent claims:

• Claim 1 (Cable): This claim describes an active Ethernet cable designed for high-speed data transmission. It includes two "data recovery and re-modulation" (DRR) devices, one at each end, connected by electrical conductors. Each DRR device handles data streams going to and from a host device via a connector plug. A key feature is that these DRR devices "pre-equalize" the signals traveling through the internal electrical conductors of the cable using specific filter settings stored permanently in memory. This pre-equalization helps overcome signal degradation over longer cable lengths.

• Claim 8 (Cable Manufacturing Method): This claim outlines a method for making such an active Ethernet cable. It involves connecting two DRR devices to their respective connector plugs and then connecting electrical conductors between these DRR devices. Similar to Claim 1, the DRR devices are configured to convert multi-lane data streams and perform pre-equalization of the electrical signals traveling through the cable's conductors using transmit filter coefficients stored in nonvolatile memories.

• Claim 15 (Communications Method): This claim describes a method for using the active Ethernet cable for communication. It involves plugging the cable's two end connectors into host interface ports. Each DRR device in the cable converts incoming multi-lane data from its host into electrical signals for transmission through the cable's conductors to the other DRR device. Conversely, it receives electrical signals from the cable and converts them back into multi-lane data for its host. This method also explicitly includes the DRR devices performing pre-equalization on the electrical transit signals using stored transmit filter coefficients.

Litigation Status:
As of April 26, 2026, US Patent 10877233 is active. The patent has been cited in several ongoing legal proceedings. Multiple US cases have been filed in the Texas Eastern District Court and Delaware District Court. Additionally, there are Inter Partes Review (IPR) cases filed before the Patent Trial and Appeal Board (PTAB), including IPR2025-01218, which is listed as "Pending - Instituted". The patent is also involved in an International Trade Commission (ITC) investigation, specifically Case 337-1446, titled "Certain Active Electrical Cables and Components Thereof," where Credo Technology Group Ltd. is a complainant, alleging patent infringement. A direct search of CAFC 2026 dockets for this specific patent number did not return explicit results, but the linked litigation information confirms ongoing legal challenges.