• M. Wendt, A. Lunin, N. Solyak, V.P. Yakovlev
  Fermilab, Batavia
• N.C. Chritin, H. Schmickler, L. Søby
  CERN, Geneva

In the context of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.