Noise temperature is a way to express the amount of noise power in an electrical system as if it were generated by a physical temperature.
Key Concepts:
- Definition: It represents the temperature at which a resistor would generate the same noise power as that measured in the system.
- Unit: Measured in kelvins (K).
- Equivalent Concept: Even if the noise doesn’t literally come from a hot object, this approach translates noise into an equivalent thermal origin, helping engineers analyze and compare systems.
Why It Matters:
- Noise temperature is especially useful in radio astronomy, satellite communications, and microwave systems, where system sensitivity is critical.
- Lower noise temperatures mean higher system sensitivity and better signal-to-noise ratio (SNR).
By converting noise power into an equivalent temperature, noise temperature provides a clear, physical benchmark for evaluating and minimizing unwanted signals.