# Accession Number:

## AD0276447

# Title:

## THE LINEAR THEORY OF SIGNAL-TO-NOISE RATIO IN BACKWARD-WAVE OSCILLATORS

# Descriptive Note:

# Corporate Author:

## CORNELL UNIV ITHACA N Y

# Personal Author(s):

# Report Date:

## 1961-09-15

# Pagination or Media Count:

## 1.0

# Abstract:

This study uses a linear analysis to predict the SN of a backward-wave oscillator, considered as a local oscillator. Local oscillator RF power is calculated using an approximate expression for efficiency. Noise power is found by calculating skirt gain and noise figure for each side band. The analysis assumes that skirt gain can be calculated from linear theory for the start-oscillation condition. Losses are neglected. Where necessary, equations developed by other authors for small values of the impedance parameter, C, are modified to allow large-C calculations. All the basic equations and their modifications are reviewed in the appendices. This study shows that linear theory predicts that the impedance parameter may be adjusted to achieve an optimum SN. The value of C obtained is in the neighborhood of 0.003 and is lower than the value of C usually found in commercial backward-wave oscillators. The results indicate that an order of magnitude improvement in R may be expected. Author