Methods and Instruments for Phase Noise Measurement
Application Notes
Phase noise is a critical parameter in electronic systems, affecting the performance of communication devices, radar systems, and precision oscillators. Understanding phase noise and accurately measuring it are essential for designing reliable and high-performance systems. In this article, we delve into various methods for measuring phase noise and explore the instruments commonly used for this purpose. We’ll discuss the theoretical foundations, practical considerations, and advantages and disadvantages of each method. Additionally, we’ll introduce typical instruments employed in phase noise testing. Article outline：
Methods and Instruments for Phase Noise Measurement
1. Concept of Phase Noise
This chapter introduces the concept of phase noise and mathematical expression, its relationship with frequency stability and representation in the frequency domain.
2. Methods for Measuring Phase Noise
This chapter discusses various methods for measuring phase noise, including:
o Direct Spectrum Analyzer Measure Method: Will show the measurement principles and circuit diagram, analysis advantages (e.g., simplicity) and disadvantages (e.g., inclusion of AM noise, sensitivity limited to LO noise).
o Reference Source/Phase-Locked Loop (PLL) Measurement Method: Will draft the measurement principle diagram, explain the principles from a mathematical point of view, analysis this method’s advantages and disadvantages.
o Frequency Discrimination Method: Will draft the measurement principle diagram, explain the principles with some diagrams, final analysis this method’s advantages and disadvantages.
o Cross-correlation Method: Will draft the measurement principle diagram, explain the principles with some diagrams, final analysis this method’s advantages and disadvantages. Finally summarize the comparison of these methods into a table.
3. Typical Instruments can be used for Phase Noise
Discuss measurement examples using instruments such as spectrum analyzers, the E5500 phase noise test system, and the N5511 phase noise test system.