低噪声放大器在毫米波辐射计中的应用研究

针对传统全功率辐射计灵敏度低、结构复杂、等效噪声温度高、功耗高等特点,采用低噪声放大器代替传统全功率辐射计的检波前部分,对天线接收到的微弱热辐射信号直接在射频段进行放大后直接检波,提高了辐射计的灵敏度。首先,分析了辐射计的工作原理;然后,分析了辐射计灵敏度及其影响因素;最后,进行了改进后辐射计样机设计并详细计算了灵敏度指标;且对样机性能进行了实际测量。通过对比分析表明,低噪声放大器的引入使得同等条件下毫米波辐射计的灵敏度得到了很大提升;同时具有功耗低、体积小、噪声小、结构简单等优点,有利于毫米波辐射计在弹载武器上的应用。

Application of Low Noise Amplifier in Millimeter Wave Radiometer

Aiming at the characteristics of low sensitivity, complex structure, high equivalent noise temperature and high power consumption of the traditional full power radiometer, the low noise amplifier is used to replace its'' pre-detection part. Thus the weak heat radiation signal received by the antenna is directly detection after amplified in radio frequency band, the sensitivity of radiometer is greatly improved. Firstly, the working principle of the radiometer is analyzed. Then, the sensitivity and influencing factors of the radiometer are analyzed. Finally, the improved radiometer prototype is designed and the sensitivity is calculated in detail. Meanwhile, the performance of the prototype is tested. The comparison shows that with the introduction of low noise amplifier, the sensitivity of millimeter wave radiometer has been greatly improved under the same conditions, meanwhile has the advantages of low power consumption, small volume, low noise, and simple structure. It provides a new guidance for the application of millimeter wave radiometer on bomb weapon.