宽频带天线罩电气性能计算中的四端网络法

The Four-Terminal Network in Calculation Electrical Property of the Wideband Radome

摘要: 宽频带天线罩除了要有精确的气动外形、足够的强度、良好的耐热及隔热性能，以适应飞行过程中的气动力、气动热和恶劣气候等环境，而且还必须在宽频段范围内具有优异的透波性能，最大限度地降低天线罩对天线辐射的电磁波的影响，以满足通讯或雷达制导的要求，因此，必须能够对宽频带天线罩的电气性能进行精确的计算。本文首先简要介绍了用于天线罩单层结构的介质平板的电气性能解析表示式，然后以宽频带夹层结构天线罩为研究对象，详细阐述了基于微波等效理论的四端网络法，并应用该方法对天线罩多层介质平板结构的功率透过系数、反射系数和插入相位移进行了分析计算，最后以五层介质平板和单层平板为实例，通过计算进行对比证明了多层介质平板对电波频带的延展性。

Abstract: Radome, which locates at the forefront end of the missile, is a key component of a missile. It not only provides the necessary pneumatic profile for the missile and endures the pneumatic force/ heat and bad circumstance, but also is desirable to exhibit superior electromagnetic transmission characteristics. The future war environment is complicated and the anti-radiation missile arises. Anti-radiation missile asks that radome works in relatively wide band or multiple frequency bands. Therefore, the electrical properties of the wideband radome must be calculated and designed accurately with higher precision. In the present work, the analytical expressions of the electrical properties of monolayer dielectric flat for the radome are introduced briefly and then, the four-terminal network is presented in detail for the wideband sandwich radome based on the theory of microwave equivalent. Furthermore, the transmission coefficient, reflex coefficient and phase displacement of the radome’s multilayer dielectric flat are analyzed and calculated by this method and the simplicity and availability of this method are proved. Finally, the electrical prop-erties of a five layer dielectric flat and a single dielectric flat are calculated and compared to verify the ductility of multilayer dielectric flat for electromagnetic wave frequency band. This work is meaningful for the further study of the wideband radome’s electrical properties.