【摘要】 射电天文接收机的灵敏度是射电望远镜的重要参数之一,影响灵敏度的两个因素为系统噪声和系统增益的不确定性,而其中系统增益的不确定性为主要因素。目前大多采用低噪放大器来提高灵敏度,而随着低噪技术的逐渐成熟,要进一步降低系统噪声已经越来越难。因此从改善系统增益的不确定性来考虑,提出了数字增益自动补偿的方法来改善系统增益,提高射电接收机灵敏度。并利用LabVIEW进行仿真验证,证明了方法的有效性和可行性。仿真结果为现行体制的射电天文接收机的系统研制提供理论依据和具体的解决方法。更多还原

【Abstract】 Sensitivity of radio astronomy receiver is one of the most important parameters of radio telescope. It is influenced by uncertainties of system noise and system gain,mostly by uncertainties of system gain. Currently,low noise amplifiers are used to improve the sensitivity. But,as the low noise technology become more and more mature,it is too difficult to reduce further the system noise. So,the improvement of uncertainty of system gain is considered. An automatic gain compensation algorithm is proposed to improve system gain and sensitivity of radio telescope. The results of simulation based on LabVIEW show that the method is valid and feasible. The simulation results provide a theoretical basis and specific solutions for current research of radio astronomy receiver system.更多还原