为减小光子型红外探测器的热噪声,通常采用降低探测器工作温度和提高其自身阻值的办法。例如,用于低背景辐射条件下的高灵敏InSb(PV)探测器,工作温度低达4.2K,零偏电阻高达10~8～10~(10)Ω,从而使器件的NEP值达到10~(-16)W/Hz~(1/2)的水平。在这种条件下,前置放大器常常成为限制灵敏度及系统性能的主要障碍。常用的互阻型前置放大器 In order to reduce the thermal noise of the photon-type infrared detector, a method of reducing the working temperature of the detector and improving the resistance of the detector is usually adopted. For example, a highly sensitive InSb (PV) detector for low background radiation has operating temperatures as low as 4.2K and zero offset resistance as high as 10 ~ 8 ~ 10 ~ (10) Ω, resulting in a NEP of 10 ~ (-16) W / Hz ~ (1/2) level. Under these conditions, preamplifiers often become a major obstacle to limit sensitivity and system performance. Commonly used transimpedance preamplifier