High Speed Gaas Acoustic Charge Transport Multiplexer

Abstract

The application of GaAs acoustic charge transport (ACT) technology to the development of high speed charge read-out multiplexers for imaging systems is described. Barrier storage cell structures are developed to permit extended time integration of signal charge directly in the ACT channel while inhibiting SAW charge transport. These storage cells, coupled with lateral ACT channel charge injectors and a GaAs MESFET based non-destructive charge detec-tion circuit form the basis for a focal plane compatible multiplexer technology with high read-out rate and large dynamic range. The high performance charge transfer characteristics and focal plane compatibility obtained from cryogenic ACT device operation are demonstrated. The basic structure, func-tional principles and experimental operation of a single channel 64 cell developmental ACT multiplexer operating at 360 MHz SAW clock rate are presented. The work indicates that ACT technology has significant potential for high speed image read-out applications.