Understanding Noise Sources and Measurements: BJT Transistors Explained

Discover the fundamentals of noise sources and measurements in this detailed tutorial! Gregory demonstrates how to use a BJT transistor as a noise source, exploring its configuration with a reverse-biased base-emitter junction and a series of common-emitter amplifiers. Using a Spectrum Analyzer with a noise marker function, Gregory analyzes circuit output noise, estimating the BJT's Excess Noise Ratio (ENR) by factoring in the noise floor and the amplification gain slope. Key takeaways include: - Calculating Noise Power Density and Noise Temperature for accurate measurements. - Understanding noise behavior through practical, easy-to-follow steps. - This video is perfect for electronics enthusiasts and professionals looking to deepen their understanding of noise characteristics and measurement techniques. BJT PN Junction Noise Source https://gusbertianalog.com/bjt-pn-junction-noise-source/ Video about Noise Temperature and SNR https://youtu.be/if_e92rpsNY This video was made possible by Patreon support: https://patreon.com/allelectronics 00:42 - Circuit Overview: Understanding the Measurement Setup 01:32 - Why Measure Noise? The Motivation Behind the Analysis 02:54 - Noise Characteristics: Key Concepts and Behavior 04:14 - Calculating Noise Power Density Explained 05:48 - Reverse-Biased Base-Emitter Junction in BJT Transistors 06:46 - Spectrum Analyzer Basics: Noise Measurement Techniques 08:08 - Role of RBW and Noise Marker in Noise Analysis 11:24 - Automated Noise Measurements for Improved Accuracy 14:54 - Amplifier Gain De-Embedding: Step-by-Step Process 17:10 - Estimating Excess Noise Ratio (ENR) for BJTs 19:00 - Spectrum Analyzer Noise Floor: Correction Techniques 23:04 - Detailed Circuit Description and Configuration 26:04 - Noise Sources: Zener Effect vs. Avalanche Breakdown