射电天文研究室知识库

基于ROACH开发平台设计了一套适用于微波全息法测量的高性能实时数字相关机,采用了带通采样技术,无需在相关机之前进行基带转换,使全息测量硬件系统更加简洁;采样速率为10 Mbps~1 000 Mbps可调,采用数字混频、数字滤波,信号带宽和频率分辨率都易于调整,具有很大的灵活性和可扩展性。测试结果表明该相关机测量精度高、稳定性好、准确可靠。

We have developed a real-time digital correlator for microwave holography based on the ＲOACH hardware platform． This correlator has high levels of flexibility and extensibility． First，the correlator does not require any baseband transformation for its input signals． This is achieved by using bandpass sampling to dramatically simplify the hardware system for microwave holography． Second，the sampling rate of the correlator is adjustable within the range 10Mbps to 1000Mbps． Together with the use of a digital frequency mixer and a digital filter，this makes it convenient to adjust bandwidths and frequency resolutions of signals．Our test results show that the correlator has a high measurement precision and a high level of stability，which should ensure accurate and reliable results in future applications．