用频设备二阶互调低频阻塞效应建模评估方法

针对用频设备复杂电磁环境适应性试验评估的技术需求，从二阶互调低频阻塞效应机理出发，引入二阶互调低频阻塞干扰因子、低频干扰电平相对值，建立了二阶互调低频阻塞效应模型.理论推导与实验测定相结合，给出了二阶互调低频阻塞效应模型参数的确定方法和建模评估流程，以导航接收机作为受试设备进行了实验验证.结果表明:利用测试确定的二阶互调低频阻塞效应模型参数，依据用频设备单频电磁辐射阻塞临界干扰场强测试数据和环境电磁场频谱分布参数，能够客观评估用频设备的二阶互调低频阻塞效应，误差在2 dB以内. 

Modeling and Evaluating Method of Second-Order Intermodulation LF Blocking Effect for Spectrum-Dependent Equipment

To test and evaluate the adaptability of the spectrum-dependent equipment to complex electromagnetic environment, introducing a LF blocking interference factor and the relative value of LF interference level, a second-order intermodulation LF blocking effect model was established to investigate the mechanism of second-order intermodulation LF blocking effect. Combining theoretical derivation and experimental measurement, a method was provided to determine the model parameter, the modeling and evaluating processes were established for the second-order intermodulation LF blocking effect. Finally, taking a satellite navigation receiver as the test equipment, an experimental verification was carried out. The results show that, using the second-order intermodulation LF blocking effect model parameters of the equipment under test at a specific working frequency, according to the tested data of the critical interference field strength of the single frequency electromagnetic radiation blocking and the distribution parameters of environmental electromagnetic field spectrum, the second-order intermodulation LF blocking effect of the spectrum-dependent equipment can be objectively evaluated, error is within 2 dB.