VXI based multibunch detector and QPSK modulator for the PEP-II/ALS/DA/spl Phi/NE longitudinal feedback system

The PEP-II/ALS/DA/spl Phi/NE feedback systems are complex systems implemented using analog, digital and microwave circuits. The VXI hardware implementation for the front-end and back-end analog processing modules is presented. The front-end module produces a baseband beam phase signal from pickups using a microwave tone burst generator. The back-end VXI module generates an AM/QPSK modulated signal from a baseband correction signal computed in a digital signal processor. These components are implemented in VXI packages that allow a wide spectrum of system functions including a 120 MHz bandwidth rms detector, reference phase servo, woofer link to the RF control system, standard VXI status/control, and user defined registers. The details of the design and implementation of the VXI modules including performance characteristics are presented.