Abstract: In a cooperative collision avoidance system, probe signals are inhibited for a predetermined time period to prevent autogenetic false alarms, that is, false replies to one's own interrogation probes.

Abstract: In a cooperative collision avoidance system the detected reply signals to interrogation probe signals are correlated by a digital circuit that processes all the reply signals identifying targets over non-targets ("fruit"). The correlator is capable of detecting all targets in any desired range during a given correlation period and is provided with means to reduce the effect of bridging or straddling adjacent bins in the correlator to minimize thereby the duplication of detected replies which would overload the following processor and cause loss of desired replies.

Abstract: The collector potential of a resistively loaded common base amplifier tends to change if its emitter current is altered to affect its emitter resistance and thereby control its gain. This tendency arises because of the change in transistor collector current, which is substantially the same value as the change in its emitter current, acting on the resistive load in accordance with Ohm's Law. A control current is applied to diode means to develop a potential thereacross, which is applied to the base emitter junction of the transistor to control its emitter current. This establishes a known proportion of control current to transistor emitter and collector currents. Changes in the transistor collector current are then compensated for by another current proportional to the control current applied at the transistor collector electrode, thereby to counteract the tendency for the transistor collector potential to change as the gain of the common-base transistor amplifier is changed.

Abstract: A common-emitter amplifier transistor has its gain controlled by change of its transconductance as a function of its quiescent emitter current. A first controlled current applied to a diode means develops a potential thereacross which is applied between the base and emitter electrodes of the amplifier transistor. This configuration causes the quiescent collector and emitter currents of the amplifier transistor to be in well-defined proportion to the first controlled current. This permits a second controlled current linearly related to the first to be used to counteract changes in the quiescent collector current of the common-base amplifier transistor, insofar as being coupled to the amplifier load.