大口径反射面天线微波短脉冲辐射特性的频域分析方法

Frequency Domain Analysis on Radiation Characteristics of Large Reflector Antennas Excited by Short Microwave Pulse

建立了等效基带模型的频域方法,分析了大口径反射面天线微波短脉冲辐射特性,理论推导了辐射场基带波形的重构方法。以Ku波段4.5m口径的单反射面天线为例进行仿真验证,重构出天线主瓣、3dB波束方向、第1,2,3旁瓣的辐射场基带波形。仿真结果表明:在主瓣和3dB波束方向辐射场波形与辐射源基带波形完全一致,但是第1,2,3旁瓣辐射场波形出现轻微畸变。

An equivalent baseband method in frequency domain is proposed to analyze the characteristics of short pulses radiated by the reflector antenna with large diameter, and the baseband waveform reconstruction method of the radiation field is derived theoretically. Tak-ing the antenna with the diameter of 4. 5 m in Ku-band as an example, the baseband wave-forms of the main lobe, the direction of the 3 dB antenna beam, and the first to the third side lobes are reconstructed by the proposed method. It is found that the radiation waveforms of the main lobe and the direction 3 dB beam are in good agreement with those of the radiation source, while the radiation waveforms of the first to the third side lobes show a slight distorted.