射电天文研究组知识库

30~300 MHz的低频段陆基天线阵是重要的射电观测设备,在该频段进行射电观测面临无线电环境复杂、天空背景温度高等特点。介绍了一种基于微波芯片设计的新型低频段模拟接收机。接收机由初级带通滤波器(30~70 MHz)、初级放大器、次级带通滤波器(55~65 MHz)、180°移相器、两个次级放大器组成。在测试云南天文台短波段无线电环境的基础上,接收机实现了对55~65 MHz可观测频段的选通和放大,整机噪声约为320 K,增益63 d B左右。同时作为中国射电天文低频阵前期研究的一部分,由于采用单片微波集成电路(Monolithic Microwave Integrated Circuit,MMIC)芯片,接收机具有体积小、成本低、易于量产等特点。

The Ground-based antenna arrays are important radio observation instruments in low (Very High Frequency) band, but in this band, the observations have to face the bad radio environments and the high sky temperature.  In this paper, we introduce a new kind of analog receiver working in low band based on the MMIC (Microwave Monolithic Integrated Circuit) chips. This receiver consists of primary band pass filter, primary amplifier, secondary band pass filter, 180 degree phase shifter and two secondary primary amplifiers. Based on the radio environment testing results in the Yunnan observation site, this analog receiver achieves band passing and amplifying for the observation band from 55-65MHz, and this receiver' s system noise temperature is nearly 320K, the gain is nearly 63dB. At the same time, as a part of the Chinese low frequency band observation net，based on the MMIC technologies, this receiver has smaller volume, lower price and is easy to copy.