论文部分内容阅读
在混合式焦平面阵列中,探测器和读出电路的耦合通过输入级电路实现。为分析输入电路对探测器-放大器系统性能的影响,用分立元件设计制作了一个三级的前置放大器并进行了模拟实验,实验表明放大器输入级噪声是造成探测器信噪比下降的主要因素,应用中应该选用具有特定噪声性能的放大器与探测器匹配。研究了焦平面中常用的直接注入(DI)和电容反馈放大电路(CTIA)与探测器耦合时在噪声、输入阻抗、工作点匹配等方面应具备的条件。提出了临界输入阻抗的概念,实验表明,当电路的输入阻抗低于此临界值时(对于GaN p!i!n光伏探测器来说约为106Ω),焦平面才能获得较高的注入效率。
In a hybrid focal plane array, the coupling of the detector and readout circuitry is done through input stage circuitry. In order to analyze the influence of the input circuit on the performance of the detector-amplifier system, a three-stage preamplifier is designed by discrete components and a simulation experiment is carried out. The experimental results show that the input-level noise of the amplifier is the main factor that causes the signal- , The application should be selected with a specific noise amplifier and detector performance matching. The conditions of noise, input impedance, matching of working point and so on when using direct injection (DI) and capacitive feedback amplifier circuit (CTIA) which are commonly used in the focal plane to couple with the detector are studied. The concept of critical input impedance is presented. Experiments show that the focal plane achieves higher injection efficiency when the input impedance of the circuit is below this threshold (about 106 Ω for GaN p! I! N PV detectors).