Comparison of an Affordable Open-Source Phase Noise Analyzer With Its Commercial Counterpart

Phase noise refers to random fluctuations in the phase of a signal, typically caused by various factors such as electronic components, thermal noise, and environmental conditions. Precise measurement and thorough characterization of phase noise are crucial for evaluating the stability of ultralow phase noise oscillators. Expensive industrial phase noise analyzers can precisely measure the phase noise of ultralow phase noise oscillators. However, an affordable open-source phase noise analyzer that can be easily set up is currently lacking. The objectives of this article are to test an open-source phase noise analyzer, the direct digital phase noise measurement bench developed by A. Holme (called AH analyzer in this article), and compare it to a commercial phase noise analyzer, the 53100A. Multiple simultaneous phase noise measures and noise floors on analyzers were made to highlight their differences. The open-source analyzer performance turned out to be on par with 53100A's performance, except with the measurement of ultralow phase noise oscillators approaching −132 dBc/Hz at 1-Hz frequencies.