Accession Number:

ADD013294

Title:

Linear Frequency Sweep Generator for Continuous Transmission FM Sonar.

Descriptive Note:

Patent, Filed 2 Oct 81, patented 9 Aug 83,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

Report Date:

1983-08-09

Pagination or Media Count:

4.0

Abstract:

A device for producing a varying frequency sine wave synthesized so that the frequency is swept linearly with time for use in a continuous transmission FM sonar. A crystal clock, divider and a 16-bit digital output sweep pointer produce 2 to the 16th power counts for each sweep period Ts. The 2 to the 16th power counts are applied to a 16 bit digital analog converter to provide a highly linear voltage ramp the smoothed result of 2 to the 16th power steps. The ramp is converted to a proportional frequency which is applied to a 5 bit digital counter to access a read only memory programmed to provide a digital to analog converter to produce a voltage output that is a 32 stepped approximation of a sinewave at a frequency which increases between f1 and f2 with linearity of the ramp voltage. A filter smoothes the output.

Subject Categories:

  • Acoustic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE