超宽带下变频组件设计

Ultra Wideband Cryogenic Receiver Down-Converter Moudule Design

射电望远镜是天文观测的主要设备,其中接收设备即低温接收机决定了天文观测系统性能。目前射电望远镜的宽频带需求越来越高,这对接收机变频性能的要求也越来越高。提出了一种组合变频方案,实现宽带信号能够变频到窄带信号,以满足系统接收不同工作带宽信号的需求。本组件将2路2 GHz~14 GHz双极化射频信号经组合变频实现频率搬迁到中频,供后续的数字终端处理,并且每路都可以采用不同带宽的射频频率,具有独立性。变频通道双通道输出频率可在70 MHz~1000 MHz或者500 MHz~1000 MHz之间切换。通过方案分析,电路优化设计,以及仿真计算实现了该组件,且其性能指标与预期相符。

Radio telescopes are the main equipment for astronomical observations,in which Cryogenic receiver of the receiving system determines the performance of the radio telescope.As the core module of the receiving system,it requires frequency conversion component with higher performance.A combined frequency conversion scheme is proposed to convert wideband signals to narrowband signals to meet the needs of the system to receive signals of different working bandwidths.This component takes 2 channels of 2 GHz~14 CHz dual-polarized radio frequency signals,achieves frequency shift through combined frequency conversion and output intermediate frequency signals for subsequent data acquisition unit measurement.Each channel can take radio frequency with different bandwidth,which is independent.The frequency conversion channel adopts a dual-channel design.Each RF input signal is converted to an intermediate frequency signal with a switchable bandwidth,which is 70 MHz~1000 MHz or 500 MHz~1000 MHz.Through scheme selection,circuit optimization,and simulation calculation,the component is designed and its performance meets the claim.