红外焦平面阵列读出电路非均匀性研究

Study on non-uniformity of ROIC for IRFPA

读出电路对红外焦平面阵列成像系统的非均匀性有重要影响,采用动态非线性系统函数的泰勒级数建立功能电路单元的通用非均匀性模型,按照模拟型读出电路的一般结构建立读出电路的非均匀性模型,利用高斯噪声和柏林噪声模拟读出电路参数的空间随机分布,采用三维噪声的空间分量量化评估非均匀性,采用等长的矩阵模型简化阵列信号串行读出的时空转换过程,分析了噪声模型、多通道缓冲和响应非线性的非均匀特性,并指导某320×256阵列读出电路进行了非均匀特性仿真和优化。该方法能够对读出电路的非均匀性进行系统级仿真评估,并为其工程优化提供指导。

The ROIC has an important influence on the non-uniformity of the IRFPA device.The nonuniformity model of general system unit was established by using the Taylor series of the dynamic nonlinear system function,and the ROIC non-uniformity model was established according to common architecture of analog ROIC.The spatial distribution characteristic of circuit statur parameters was modeled by mixing Berlin noise and Gaussion noise.The non-uniformity was evaluated with the spatial components of standard three demensions noise model.The time to sptial convertion from array signals to serial outputs was simplified by equal size convertion matrix.The non-uniformity of noise,multi-channel buffers and resposing nonlinearity were analized.The non-uniformity of a 320×256 array ROIC was evaluated by simulation and improved by circuit optimization based on the proposed model.Simulaiton results show that it can be used to evaluate the nonuniformity and to assist with non-uniformity engineering optimization of ROIC at the system level.