Electronic counter-counter-measure device

Claim 2

In combination with a tracking radar, from which are available video and range gate signals, and having first amplifier means and subsequent error detector means, electronic counter-counter-measure means comprising: coincidence means for providing an output signal representative of coincidence of the leading edge of true target video and a range gate; means responsive to the output of said coincidence means for providing a blanking signal delayed with reference to said coincidence; said radar being rendered unresponsive to video received during a predetermined time period following the video upon which the coincidence means has operated.

Claim 3

The combination defined in claim 1, and wherein said means responsive to the output of said coincidence means comprises: means for introducing a predetermined delay in the output of said coincidence means; interval timing means responsive to the delayed output of said coincidence means to generate an output pulse of predetermined duration; second amplifier means responsive to said output pulse to generate a blanking signal of said predetermined duration; and means connecting the blanking signal output of said second amplifier means to said first amplifier means so that said receiver is shut off by said blanking signal after the leading edge and at least part of the trailing edge of true target video is passed to said error detector means, whereby said error detector means is unaffected by false target video following said true target video.

Claim 4

The combination defined in claim 2, and wherein said interval timing means comprises a one shot multivibrator.

Claim 5

The combination defined in claim 3, and wherein said coincidence means comprises a sensitivity control for selecting the point along the sloping leading edge of true target video which will initiate an output of the coincidence means, whereby adjustment of the time at which said blanking signal begins can be affected by said sensitivity control.

Claim 6

The combination as defined in claim 2, and further comprising: an adjustable delay means connected to receive said range gate and operative to delay the leading edge thereof by a selected amount of time; means connecting the delayed range gate output of said adjustable delay means as an input to said interval timing means; said interval timing means being responsive to said delayed range gate input to initiate said pulse of predetermined duration in the absence of true target video and at a time slightly later than if initiated by true target video.

Claim 7

The combination defined in claim 5, and wherein said interval timing means comprises a one shot multivibrator.

Claim 8

The combination defined in claim 6, and wherein said adjustable delay means comprises: a first inverter amplifier connected to receive said range gate and provide an inverted output corresponding to said range gate; a potentiometer connected to said output of said first inverter amplifier; a capacitor connected to the wiper of said potentiometer so as to be charged by the output of said first inverter amplifier at a rate selected by said potentiometer; a second inverter amplifier connected to said capacitor and operative to provide an output condition indicative of the time that said capacitor is charged to a predetermined level; and a third inverter amplifier responsive to said output condition of said second inverter amplifier to provide said delayed range gate as the output of said delay means.

Claim 9

In combination with a tracking radar, from which are available signals including video and range gate, and having first amplifier means and subsequent error detector means, electronic counter-counter-measure means comprising: first protection and interface means connected to receive said video and comprising a first coupling capacitor as an input connection to a first voltage divider means including a potentiometer, and diode means connected across the output of said first voltage divider means; second protection and interface means connected to receive said range gate and comprising a second coupling capacitor as an input connection to a second voltage divider means including a plurality of series connected resistors, and diode means connected across the output of said second voltage divider means; a first time delay and inverter amplifier connected to receive the output of said first voltage divider means; a second time delay and inverter amplifier connected to receive the output of said second voltage divider means; first NAND gate means connected to receive the outputs of said first and second delay and inverter amplifiers and to provide an output condition representative of coincidence of a predetermined level of said video and presence of said range gate; interval timing means responsive to said output condition of said first NAND gate means to initiate an output condition for a predetermined time period, said interval timing means comprising second, third, and fourth NAND gate means, said second and third NAND gate means being coupled by an RC network and a feedback path to function as a monostable multivibrator for determining said predetermined time period, said fourth NAND gate being operative to invert the output of said third NAND gate means; a transistor amplifier means coupled to the output of said fourth NAND gate means and responsive thereto to generate as an output a video blanking pulse having a time duration equal to said predetermined time period starting at a point in time after occurrence of said predetermined level of said video, said point in time being determined at least in part by adjustment of said potentiometer and in part by time delays in said time delay and inverter amplifiers, in said NAND gate means, and in said transistor amplifier means; and means coupling said blanking pulse output to said first amplifier means whereby said video is blanked for a period equal in duration to said predetermined time period and starting substantially at said point in time after occurrence of said predetermined level of said video.

Claim 10

In combination with a tracking radar, from which are available signals including video and range gate, and having first amplifier means and subsequent error detector means, electronic counter-counter-measure means comprising: first protection and interface means connected to receive said video and comprising a first coupling capacitor as an input connection to a first voltage divider means including a potentiometer, and diode means connected across the output of said first voltage divider means; second protection and interface means connected to receive said range gate and comprising a second coupling capacitor as an input connection to a second voltage divider means including a plurality of series connected resistors, and diode means connected across the output of said second voltage divider means; a first time delay and inverter amplifier connected to receive the output of said first voltage divider means; a second time delay and inverter amplifier connected to receive the output of said second voltage divider means; first NAND gate means connected to receive the outputs of said first and second delay and inverter amplifiers and to provide an output condition representative of coincidence of a predetermined level of said video and presence of said range gate; interval timing means responsive to said output condition of said first NAND gate means to initiate an output condition for a predetermined time period, said interval timing means comprising second, third, and fourth NAND gate means, said second and third NAND gate means being coupled by an RC network and a feedback path to function as a monostable multivibrator for determining said predetermined time period, said fourth NAND gate being operative to invert the output of said third NAND gate means; a transistor amplifier means coupled to the output of said fourth NAND gate means and responsive thereto to generate as an output a video blanking pulse having a time duration equal to said predetermined time period starting at a point in time after occurrence of said predetermined level of said video, said point in time being determined at least in part by adjustment of said potentiometer and in part by time delays in said time delay and inverter amplifiers, in said NAND gate means, and in said transistor amplifier means; and means coupling said blanking pulse output to said first amplifier means whereby said video is blanked for a period equal in duration to said predetermined time period and starting substantially at said point in time after occurrence of said predetermined level of said video.