高灵敏太赫兹阵列检测器的低噪声读出电路

Low-Noise Readout Circuit for Sensitive Array Terahertz Radiation Detectors

本文基于Nb5N6微测辐射热计(microbolometer)低噪声、高阻抗和高响应率的特性,为1 ×64阵列的Nb5N6 microbolometer设计了极低噪声的多通道读出电路。读出电路包含直流偏置电路,一、二级放大电路和多通道选择电路等几个部分,对检测器阻抗变化具有较强的鲁棒性,成功实现对64通道的微弱电压信号的放大和采集。电路具有优异的低噪性能,测量且分析比较了电路噪声对Nb5N6 microbolometer的影响。电路单通道输入阻抗达100 kΩ,增益约为60 dB,带宽约为30 kHz,噪声约为8.6 nV/Hz1/2。

A low-noise multi-channel readout circuit is designed for 1 ×64 array Nb5N6 microbolometers based on Nb5N6 microbolometer’s ultralow noise and high responsivity. The readout circuit consists of DC offset circuit, first and second stage amplifier circuits and multi-channel selection circuit, which is robust against the different impedance of the detectors. 64 weak voltage signals are successfully amplified and collected by the readout circuit. The noise of the circuit, as low as Nb5N6 microbolometers’, is 8.6 nV/Hz1/2. The effect of circuit’s noise on Nb5N6 microbolometer is measured and analyzed. The input impedance, gain and bandwidth of the circuit are 100 kΩ, 60 dB and 30 kHz respectively.