Upstream Tracker - The silicon strip tracking detector for the LHCb Upgrade

After operating for 10 years, the LHCb detector at the LHC is currently undergoing a major upgrade. New tracking detectors will be installed to improve tracking performance and to allow taking data at higher instantaneous luminosity than in previous runs. Front-end readout electronics of all subsystems is being replaced by boards with readout at collision frequency of 40 MHz. That will allow application of software-only trigger and prompt data analysis techniques. The Upstream Tracker (UT) will be located in the fringe field in front of the LHCb spectrometer magnet and will be composed of four layers of silicon strip sensors. Custom hybrid flexible circuits and front-end readout chip, SALT, were developed for powering and processing measured signals and to transfer them to the near-detector electronics. This contribution describes the design of UT components, their novel features and detector performance measured during system tests. The current status of installation and commissioning plans are also given.