RECOGNITION UNIT
Assignee
AIL SYSTEMS, INC.
Filed
Feb 13, 1959
Granted
Apr 13, 1993
Location
LAW DEPT., COMMACK ROAD, DEER PARK NEW YORK 11729
Abstract
An electronic recognition unit indicates that a flow of received information is starting when a desired bi-phased pulsed ratio signal starts to be received. The recognition unit discriminates against both noise and spurious radio signals. Desired signals are made recognizable by reversing, upon transmission, the phase of the carrier for a prescribed pattern of pulses. This technique prevents responding to unqualified continuous-wave signals. The relative phases of adjacent radio-frequency pulses of the desired pulse train convey the recognition information. When the phases of two adjacent pulses are the same a positive audio-pulse output is obtained, and if their phases differ by 180 degrees the output is negative. For a predetermined number of pulses, for example fourteen, the resulting positive and negative audio pulses are added in an audio delay circuit with appropriate inversion of the sign of the intentionally negative pulses. The procedure produces relatively large recognition signals, only when the incoming pulse train has the prescribed phase pattern.
Source: Google Patents
35 USC §181 Secrecy Order
Imposed
Mar 12, 1982
Rescinded
Apr 15, 1992
Duration
10 years, 1 month
Record Details
- Patent number
- US 5202678
- Application
- 03793212
- Aerospace match
- No
- Dataset source
- 35 USC §181 SO records