Noise analysis and optimization of a charge transformer, a noise-matching device for single electron transistors

Abstract

Operation and noise analysis of a recently proposed noise-matching device, called a charge transformer, are presented. The charge transformer consists of N identical capacitors and 3N+13N+1 switches that enable the capacitors to be connected either in series or in parallel. The device is operated by switching back and forth between these two configurations at speeds faster than the signals that will be measured. We show that an ideal charge transformer can achieve perfect noise matching between any single-electron transistor and a high capacitance device that is under test. We also discuss how a realistic charge transformer made using switches with finite capacitance and resistance should be operated to achieve optimum noise performance. © 2003 American Institute of Physics.