A divide-down RF source generation system for the Advanced Photon Source

A divide-down RF source system has been designed and built at Argonne National Laboratory to provide harmonically-related and phase-locked RF source signals between the APS 352-MHz storage ring and booster synchrotron RF systems and the 9.77-MHz and 117-MHz positron accumulator ring RF systems. The design provides rapid switching capability back to individual RF synthesizers for each one. The system also contains a digital bucket phase shifter for injection bucket selection. Input 352-MHz RF from a master synthesizer is supplied to a VXI-based ECL divider board which produces 117-MHz and 9.77-MHz square-wave outputs. These outputs are passed through low-pass filters to produce pure signals at the required fundamental frequencies. These signals, plus signals at the same frequencies from independent synthesizers, are fed to an interface chassis where source selection is made via local/remote control of coaxial relays. This chassis also produces buffered outputs at each frequency for monitoring and synchronization of ancillary equipment.