有限长宽角双锥天线的超宽带特性研究

模式匹配法利用有限长双锥天线的轴对称性求解天线电磁场边值问题，通常导致求解无限多个线性方程而得不到严格解。文中在讨论天线为宽角双锥天线的情况下,用TEM模近似天线区域中的所有模得出了天线输入阻抗的近似表达式．从而计算出双锥天线的宽带特性。利用基于有限积分法的电磁场仿真技术对平衡馈电的有限长宽角双锥天线作了计算．得到了天线在很宽频带内输入阻抗、远区辐射场与频率的关系曲线。结果表明近似表达式的计算结果与仿真结果相吻合．因此对于宽锥角天线这种使用TEM模的近似是可行的。

Study of the Ultra-wide Band Characteristics of the Wide-angle Biconical Antenna

By using symmetry and boundary conditions the field and input impedance of finite wide-angle biconical antenna can be derived by modal analysis, which generally results in solving infinite linear equations. Approximate expressions of the radiation field and input impedance are obtained by merely utilizing TEM-mode in the antenna region rather than other modes under the condition of wide cone angles. Simulations based on finite integration method are carried out in a wide frequency range for a balanced feeding finite wide-angle biconical antenna and many results including input impedance and far fields are obtained. These results are comparable to results calculated by the approximate expressions which means the approximation is advisable.