Communications: radio wave antennas – Antennas – Balanced doublet - centerfed
Patent
1971-07-28
1978-04-04
Bentley, Stephen C.
Communications: radio wave antennas
Antennas
Balanced doublet - centerfed
G01S 942
Patent
active
040830497
ABSTRACT:
There is disclosed a direction-sensitive doppler radar particularly for detecting intruders into a protected area which is free of the mechanically controlled parts of the prior art. To distinguish between an intruder and the clutter produced by the movement back and forth of trees or like growth in a wind, the doppler side bands of the clutter produced by the growth moving or swaying in opposite directions are processed so that they counteract each other. The incoming signals, both clutter and from intruders, are converted into I and Q quadrature signals, frequency or sensitivity compensated and passed through a variable bandwidth bandpass filter whose bandwidth is reduced at the low-frequency end as the clutter increases. The I and Q signals are then each converted into quadrature I3 and I4 and Q3 and Q4 signals respectively, and the products I3Q4 and I4Q3 derived and subtracted. The resulting signal produces the alarm if there is an intruder and indicates the direction of movement of the intruder.
There is also disclosed a variable-bandwidth filter whose bandpass is set by time modulation of resistance of the filter. There is also disclosed a multiplier including a balanced network. One of the parameters to be multiplied is impressed as an actuating potential on the network and the other to unbalance the network for an interval dependent on the magnitude of the latter parameter.
REFERENCES:
patent: 3680098 (1972-07-01), Harris et al.
Harrison Earnest R.
Mattern John
Bentley Stephen C.
Schron D.
Westinghouse Electric Corporation
LandOfFree
Moving target radar does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Moving target radar, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moving target radar will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-726066