2018/06/24 by Dominik Sikora, Krzysztof Czuba, Sikora, Dominik +11 · 1 citation
Engineering · Physics and Astronomy · #FOS: Physical sciences #Gyrotron and Vacuum Electronics Research #Instrumentation and Detectors (physics.ins-det) #Particle Accelerators and Free-Electron Lasers #Particle accelerators and beam dynamics
paper · pdf · doi:10.48550/arxiv.1806.09197
openalex publication_date 2018/06/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Modern high-energy particle accelerators and Free-Electron Lasers incorporate\nlarge quantities of sensitive RF and microwave frequency devices distributed\nover kilometer distances. Such devices require extreme stable phase and time\nsynchronization by means of high frequency signal distributed along the\naccelerator facility. Coaxial cables are commonly used to distribute the\nreference signal over the large machine to synchronize electronic systems and\nthey are the main source of undesirable phase drifts in the synchronization\nsystem. Signal phase drifts in cables are mainly caused by temperature and\nhumidity variations and their values usually exceed required phase\nsynchronization accuracy by more than order of magnitude. There are several\napproaches to reduce signal phase drifts in coaxial cables. This paper\ndescribes the realization of active phase stabilization system based on\ninterference phenomenon. A phase-locked signal from the transmitter is\nreflected at the end of a coaxial cable link. Directional couplers placed along\nthe cable pick up the forward and reflected signals and interfere them to\ncancel out the cable phase drifts. Distributed hardware including\ninterferometer controller/transmitter and receiver modules were built to\ndemonstrate system concept and performance. Link input and output devices used\nFPGA I/O boards with Ethernet interface to control system operation.\nSpecialized firmware and software was developed to calibrate and control the\nsystem. This paper describes the concept of interferometer link, designed\nhardware, basic control algorithms and performance evaluation results. The link\nprototype was built to distribute 1.3 GHz signal through a coaxial cable.\nMeasured phase drift suppression factor value exceeded level of 100.\n