基于射频单电子晶体管的超灵敏电荷计的模拟研究

集成单电子晶体管(single electron transistor, SET)与射频共振电路的射频单电子晶体管(radio frequency single electron transistor, RF SET)是一种高速高灵敏的电荷计。本文通过建立RF SET的等效电路模型，对共振电路及其与射频传输线的集成进行模拟分析，得到了SET阻抗的最佳匹配，获得了所需的谐振频率、品质因子和对SET阻抗的灵敏度。结果表明，受电荷调制的SET阻抗直接影响着共振电路的品质因子、阻抗和射频透射/反射系数。射频信号随着SET的阻抗降低而减小，峰位基本不变。在SET阻抗小于200 k?时，共振信号幅度随阻抗的变化率较大。透射式与反射式两种结构相比，前者共振频率及品质因子更高，后者则具有更高的灵敏度优势。

Simulation study of an extremely sensitive electrometer based on radio frequency single electron transistor

By integrating a single electron transistor (SET) with a radio resonance circuit, the radio frequency single electron transistor (RF SET) can be used as an extremely sensitive and ultra high-speed electrometer. In this work, the equivalent circuit model of RF SET is established. The resonance circuit and the integration with the RF transmission line are investigated. The optimum matching of the SET impedance, resonant frequency, quality factor and the sensitivity of the SET impedance are obtained. Results indicate that the charge-induced impedance of the SET has direct impacts on the quality factor, impedance and the transmission or reflection coefficient of the RF circuit. The radio signal decreases with increasing impedance of the SET, while the peak position remains unchanged. The amplitudes of the resonance vary significantly with impedance under 200 k?. Comparisons indicate that the transmission RF SET has higher resonance frequency and quality factor, while the reflection RF SET shows a higher sensitivity.