Development of a High Frequency Phase Reference Standard

微波测试设备的最新进展是采用直接数字合成（DDS）技术的微波源，使频率达到67GHz。当这些与最先进的矢量网络分析仪（VNA）接收器相结合时，为开发电流和电压波形测量系统（包括在非常高的频率下工作的有源负载牵引系统）开辟了新的机会。阻止这一点成为可能的主要技术障碍是提供一个精确的宽带相位基准，这是将频域VNA转换成能够处理电流和电压波形的时域接收器所需要的。已经尝试通过开发新型的相位基准标准来解决这个问题，然而，迄今为止尝试的所有方法在其操作频率方面都受到严重限制。因此，本研究项目将探讨开发一种新型相位基准的可行性，这种相位基准不受频率限制，但原则上可以用于高达67 GHz或更高的频率。

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.