Development of a High Frequency Phase Reference Standard

通过使用微波源和采用直接数字合成(DDS)技术的微波测试设备的最新进展使频率达到67 GHz。当这些与最先进的矢量网络分析仪(VNA)接收器相结合时，就有了开发电流和电压波形测量系统的新机会，包括以极高频率运行的有源负载牵引系统。阻止这成为可能的主要技术障碍是提供准确的宽带相位基准，这是将频域VNA转换为能够处理电流和电压波形的时域接收器所必需的。人们试图通过开发新型的相位基准来解决这个问题，然而迄今为止所有尝试的方法都严重地限制了它们的工作频率。因此，这项研究项目将探讨开发一种新型的相位基准的可行性，这种基准不受频率限制，但原则上可以用于67 GHz及以上的频率。

Recent advances in microwave test equipment through the use of microwave sourcesemploying Direct Digital Synthesis (DDS) techniques enable frequencies up to 67GHz to beachieved. When these are combined with state-of-the-art Vector Network Analyser (VNA)receivers, new opportunities are opened up to develop current and voltage waveformmeasurement systems, including active load-pull systems, that operate at very highfrequencies. The major technical hurdle that prevents this from being possible is the provisionof an accurate, wide-band phase reference which is required to convert a frequency domainVNA into a time domain receiver capable of handling current and voltage waveforms.Attempts have been made to solve this issue through the development of new types of phasereference standards, however all of the approaches tried to date have been severely limited intheir frequency of operation. This research project would therefore look into the feasibility ofdeveloping a new type of phase reference that is not frequency limited, but could in principlebe used to frequencies up to 67GHz and beyond.