To support strong interference signal input under "navigation warfare" scenarios,navigation receivers are requested for increasing dynamic range in analog channels.Under the given constraint condition of signal to noise ratio deterioration,a two-dimensional curve model to offer a method for dynamic range optimizing and stage gain design was put forward by the legacy analysis method.However,this method was only applicable for the AGC(automatic gain control) circuits that the output power was basically stable.A solving model involving the three-dimensional curve based on the extra parameter called the rollback value of the AGC output power was put forward.The model revealed the relationship between the circuit parameters and the dynamic range of analog channel and it is suitable for the AGC circuits with variable output power,which can achieve a larger dynamic range.To reduce the complexity of the parameter calculation in the three-dimensional model,the complex numerical solution to linear equation solution according to the features of pure attenuation network was simplified.This simplification can substantially reduce the design complexity.Test results of dynamic range are in good consistence with the expectation in practical designs,which proves the accuracy of the analysis model.%为适应"导航战"下的强干扰输入,导航接收机对模拟信道的动态范围提出了更高的要求.在给定的信噪比恶化容限约束下,原有的分析方法给出了二维曲线分析模型,得到了动态范围的优化设计及各级增益划分方法,但仅适用于输出功率基本不变的自动增益控制电路.基于增加的自动增益控制输出回退功率这一参数,提出了一种三维曲面求解模型,揭示了各电路参量与模拟信道动态范围的约束关系,可适用于输出功率变化的自动增益控制电路,以实现更高的动态范围.针对三维模型中参数求解复杂的问题,利用纯衰减网络的特性,将复杂的数值求解简化为直线求解,大幅降低了设计复杂度.在给出的设计实例中,动态范围测试结果与设计预期吻合较好,验证了方法的正确性.
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