Design of a multivariable RF control system using gainshaping in the frequency domain
Abstract
Due to the timevarying nature of the radiofrequency (RF) accelerator, RF field amplitude and phase parameters must be precisely controlled in order to confine and accelerate the charged particle beam. Typically, a feedback control system regulates the RF field, rejects noise and disturbances, and maintains operational stability over changes in the electrical structure of the accelerator. This paper describes a multivariable control system that compensates the electrical structure of the accelerator by using gainshaping in the frequency domain. The amplitude and phase quantities have been resolved into inphase and quadrature (I and Q) variables. These orthogonal variables have simple mathematical relationships, and can be analyzed using linear transfer function matrices. The transfer matrix theory has been applied to the design of the multivariable control system that regulates the RF field inphase and quadrature components. Frequencydomain controllers compensate these two signals to provide desired frequency response characteristics. A control predistorter performs an inverse coupling function, so that the I and Q components are effectively decoupled by the accelerator. Furthermore, computer interface circuitry allows the adaptive optimization of the mathematical transfer functions of the compensators.
 Publication:

Presented at the 1991 Institute of Electrical and Electronics Engineers (IEEE) Particle Accelerator Conference (PAC
 Pub Date:
 May 1991
 Bibcode:
 1991IPAC.....Q...6Z
 Keywords:

 Amplifiers;
 Control Equipment;
 Control Systems Design;
 Feedback;
 Radio Frequencies;
 Design Analysis;
 Transfer Functions;
 Communications and Radar