  The proposed Next Linear Collider (NLC) contains linac systems operating at
L,S,C, and X band. This paper describes a wideband modular low-level RF (LLRF)
system applicable for all NLC pulsed RF systems. High speed digital IF
techniques are used for both arbitrary klystron drive modulation and accurate
RF vector detection. Measurement of relative beam to RF phase, beam loading
compensation, and structure dipole modes for automated alignment are all
handled by the system. Modern signal processing techniques are also described.
