Filtronic

Superconducting quantum computers are driven by microwave signals, and Filtronic supplies some of the filters and diplexers that clean those signals up. The County Durham RF specialist, listed on AIM, won a £0.35m order in June 2022 from an unnamed quantum computing firm for parts used both in the room-temperature control rack and inside the dilution refrigerator. Under NPL's Measurement for Quantum programme, its filter modules were tested at temperatures down to 500 millikelvin, giving it validated design rules for cryogenic use. In February 2026 it opened a new 44,000 sq ft site at NETPark, Sedgefield, combining head office and factory, to expand its satellite, space and defence production.