Balanced Input Zero Differential Detector.
DEPARTMENT OF THE AIR FORCE WASHINGTON DC
Pagination or Media Count:
A sensitive and precise detector is described for application in determining the Centroid of the video pulse of a radar return echo. A tunnel diode, connected and biased in a balanced configuration with respect to ground and selected taps on a signal delay line, is the key element of the circuit. The sum and or difference of the tapped signals are formed in such a manner that a precise zero crossing, corresponding to the centroid of the pulse, may be determined. The special characteristics of the tunnel diode are utilized to achieve additional objects, base line noise immunity, multiple echo self resetting, and high speed-precision response. The tunnel diode is positioned in relation to four or more input signals and ground such that with no signal on the delay line, it is biased - at a stable low-current-high-voltage state. An incoming signal causes a series of state changes designed to Switch the diode to a second state at the time of zero crossing, resulting in the occurrence of a voltage step which, in turn, causes the differential amplifier connected to the tunnel diode to also change state-with amplification.
- Electrical and Electronic Equipment
- Active and Passive Radar Detection and Equipment