INVESTIGATION OF HIGH FREQUENCY LIMITATIONS IN MILLIMETER WAVE GENERATORS
Abstract
The relationship between the uncertainty principle and minimum amplifier noise is examined. First, the concept of coherence is discussed, and an incoherence parameter is defined in terms of the uncertainty that enters into the uncertainty principle. Harmonic oscillator states are examined for coherence. The concept of noise is then discussed and contrasted with incoherence. It is shown, with illustrations, that the two concepts are different, and that an incoherent field of a cavity mode need not exhibit noise. Spontaneous emission is examined both for coherence and noise. The origin of fundamental noise in an amplifier is shown to come from spontaneous emission of the amplification mechanism. The physical significance of the zero-point field is shown to consist only of a formal contribution to spontaneous emission, provided the amplifying mechanism is treated quantum-mechanically. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1962
- Accession Number
- AD0276940
Entities
People
- Julian Schwinger