波束波导馈电系统在深空探测天线应用中的关键技术研究

On Application of Beam Waveguide Feed Systems in Deep Space Antennas

针对波束波导馈电系统在深空探测天线应用中存在的电小尺寸镜面绕射引起波束波导传输效率降低,不同极化工作时波束指向不一致,以及TE21模跟踪时坐标转换等问题,进行深入研究并给出相应的解决方案或数学模型。通过优化椭球镜M5的曲率,解决了电小尺寸镜面绕射使波束波导传输效率下降问题,使S频段的传输效率提高约4%,35m天线副反射面的截获效率增加约11%,天线增益提高0.7dB;给出天线束峰值位置随方位、俯仰角变化的数学模型,提出了中值补偿方法,使天线左右旋极化峰值不一致增益损失减小约0.16dB,并给出TE21模跟踪时的坐标转换数学模型。这些方法和数学模型已成功应用于实际工程中,并取得了良好的效果。

Solutions and mathematical models are developed to solve problems in application of beam waveguide feed system in deep space antennas, including change of beam peak position with antenna azimuth-elevation position and the impact of electronic small reflecting surface diffraction on transmit efficiency, and coordinate conversion during tracking with TE21 modulus. As a result of improvement of the eccentricity of ellipsoid mirror M5, beam waveguide transmit efficiency at S-band is increased by about 40%, interception efficiency of the subreflector of a 35 m antenna system is increased by 11 %, and antenna gain is increased by 0.7 dB. A mathematic model is developed for changes of beam peak position with antenna azimuth-elevation position and a median value compensation method is proposed. Gain loss because of inconsistency between peaks of left-hand and right-hand polarizations is reduced by about 0.16 dB. A mathematic model is given for coordinate conversion during tracking with TE21 modulus. The methods and mathematical models are successfully used in engineering projects with good results.