Traffic radar and apparatus therefor
US4052722A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 15, 1975 |
| Grant date | Oct 4, 1977 |
| Priority date | — |
| Expiry date | Sep 15, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/586
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus is provided for determining the frequency of unknown periodic input signals and primarily generally sinusoidal signals which may be accompanied by very substantial noise. More particularly, the system for determining the frequency of unknown periodic input signals accompanied by substantial noise is adapted to a unique traffic radar or doppler radar system. The apparatus includes a phase locked loop in which the incoming signal accompanied by noise is compared with the output from a voltage controlled oscillator to generate a synthetic signal which is substantially free of noise and is well adapted for counting, measuring and display circuitry to give a direct indication of the input signal frequency or a parameter directly related to that input signal frequency. Specifically in doppler radar systems the direct readout is in "miles per hour", a direct function of doppler frequency. The signal which is being subjected to frequency determination is applied directly to the comparator portion of the phase locked loop circuit and it is also applied to the comparator portion of the phase locked loop circuit through a tunable band pass filter whereby speed of response is obtaine…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.