Accession Number:

AD0421921

Title:

AN ANALYSIS AND SYNTHESIS PROCEDURE FOR FEEDBAK FM SYSTEMS. PART A CONVENTIONAL FM SYSTEMS. PART B FEEDBACK FM SYSTEMS,

Descriptive Note:

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS

Personal Author(s):

Report Date:

1963-09-30

Pagination or Media Count:

49.0

Abstract:

An investigation of frequency-compressive feedback FM systems was made, with emphasis placed on threshold behavior. A recent evaluation of the impulsive noise component by Rice is used. It is shown that this excess-noise component predominates in the threshold region of most conventional FM systems. A new analytical expression which agrees with experimental evidence has been found for the location of the noise threshold. Two possible mechanisms causing noise threshold in a feedback FM system are examined. It is shown that the feedback threshold results in an abrupt breakdown of system performance, and therefore should not be approached too closely. It is therefore recommended that feedback systems by designed with the conventional threshold predominant. In this case, the analysis of feedback systems approaches that of conventional systems. Some modified formulas for feedback FM system performance at threshold are proposed new bounds on the performance of the systems with optimum feedback filters are derived. The maximum obtainable threshold power-bandwidth trade-off implied thereby is also determined. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE