中文摘要：

尝试引入因媒质不均匀而产生的折射效应,改进原有算法.共焦过程选用鲁棒的Capon波束成形（RCB）算法.乳房模型选用较为简单的三维（3-D）半球,为了更好地描述人体组织电参数的色散特性,各组织建模为多极柯尔-柯尔（Cole-Cole）媒质.在超宽带（UWB）平面波激励下,利用时域有限差分（FDTD）法模拟电波传播.数值应用中,乳房植入两个半径3 mm球状肿瘤,分别应用原有微波共焦成像方法和改进方法检测乳腺肿瘤.仿真结果对比显示：改进方法在复杂度略微增加的同时,提高了计算精度.

英文摘要：

Algorithms are tentatively modified by adding refraction effect due to inhomogeneous media. Robust Capon beam-forming （RCB） algorithm is used for confocal procession. A frequently-used three-dimensional （3-D） hemispherical breast model is selected. Electrical parameters of breast tissues are modeled by a multi-pole Cole-Cole model in order to consider frequency-dependent property. Finite-difference time-domain （ FDTD ） method is used to simulate wave propagation in breast with illumination of an ultra-wide band （UWB） plane wave source. In a numerical application, two spherical 3 ram-radius tumors are added into breast to test performance of original CMI method and modified version. It shows that there is improvement on computational precision with slight increase in computational complexity.