适用于高强度辐射场构建的多模反射面天线

高强度辐射场构建系统是对多种武器进行电磁辐照效应试验的关键装备，其要求在距天线一定距离的区域内产生高强度且尽量均匀分布的电磁场。本文设计了一款适用于该系统的X波段偏置卡塞格伦多模反射面天线。用反射面天线是为了获得尽可能高的增益，使期望区域内的场强尽可能大；用多模反射面理论实现了窄波束的平顶赋形，使期望区域内的场趋于均匀分布，区域外的场迅速减小。实测结果表明天线增益大于29.8 dB,3 dB波束宽度不小于4.6°，在此范围内方向图幅度起伏小于2 dB，平顶特性明显。此外，偏置的反射面天线还有馈源遮挡小、馈线损耗低和易于折叠收藏等优点，可以很好的应用于电磁环境模拟试验设备中。

Multimode reflector antenna suitable for construction of a high intensity radiated field

High intensity radiated field construction system is a key equipment for electromagnetic irradiation effect test of various weapon systems. It can excite high intensity and evenly distributed electromagnetic field in a certain distance from the antenna. In this paper, an X-band offset Cassegrain multimode reflector antenna is designed for this system. Reflector antennas are used to obtain high gain so that the field strength in the desired region is as large as possible. The flat top narrow beam is realized by using the theory of multimode reflector, which makes the field in the desired area tend to be evenly distributed, while the field outside the area decreases rapidly. The measured results show that the gain of the proposed antenna is greater than 29.8 dB, and the 3 dB beamwidth is not less than 4.6°. In this range, the amplitude fluctuation of the pattern is less than 2 dB, and the flat top characteristic is obvious. In addition, the dual-bias reflector antenna has the advantages of small feed occlusion, low feeder loss and easy folding, which can be well applied to electromagnetic environment simulation test equipment.