Spectrum Analyzer Preselector Tuning for Microwave Amplitude Accuracy
应用文章
While modern spectrum analyzers have been evolving to provide ever-better accuracy at RF frequencies, their accuracy at microwave frequencies has not generally been improving. Indeed the requirements placed on the analyzer user to achieve the best accuracy have become harder to realize with modern signals such as wideband digital modulation. Hardware and algorithms in the X-Series signal analyzers help you maintain the best accuracy without requiring a specific kind of input signal or external test signal. Microwave spectrum analyzers use preselectors to improve performance by removing unwanted mixer images and responses to local oscillator (LO) harmonics. Unfortunately these preselectors have instabilities and must be retuned frequently, and the preselector tuning previously required a signal of near-CW statistics at the frequency of interest. In the X-Series signal analyzers, noise-source tuning removes this difficult-to-satisfy req/uirement.