Design of a computer based resonator-simulator for tests of rf control systems

In order to test RF control systems for accelerator cavities without being dependent on available prototypes, a resonator-simulator has been developed. The Simulator is based on a Xilinx VIRTEX-4 FPGA module and has been configured using MATLAB Simulink with a special Xilinx blockset. The underlying model for this configuration is a parallel RLC circuit that has been parameterised with common RF quantities like the resonance frequency, driving frequency, bandwidth and quality factor. This approach allows the behaviour of normal conducting cavities with quality factors up to 10 4 as well as superconducting cavities with quality factors up to 10 9 to be simulated. Besides, it can be operated in continuous-wave mode as well as in pulsed mode. We report on the mathematical model, its digital representation and on the benchmarking against realistic cavity behaviour.