NOISE FIGURES, NOISE TEMPERATURES, AND SYSTEM SENSITIVITY
Abstract
The definitions of terms used in systems noise work are presented, as well as general techniques of describing noise power resulting from both the source and the excess noise added by the network under consideration. A unique feature presented is a unified development of 7 noise temperatures encountered in this field, with tables showing the relationships among them and their uses. A general technique for calculating the sensitivity of a receiver is presented and 3 examples are treated in detail: the simple crystal-video system, the crystal-video receiver with RF preamplification, and the superheterodyne system. All systems are divided into 2 classes for which the calculations are similar: receivers having only a simple detector, and those having some form of linear amplification preceding the detector. The final analysis of the noise performance of the system requires a comparison of the pre-detection and postdetection excess noise. This comparison is performed by referring all excess noise power to the detector input and classifying the system according to whether (a) the pre-detection noise predominates, (b) the post-detection noise predominates, or (c) the pre-detection noise and the post-detection noise are comparable in magnitude.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 10, 1961
- Accession Number
- AD0265552
Entities
People
- Philip H. Enslow Jr.
Organizations
- Stanford University