A Pulse Interference Blanker

An interference blanker is described which is effective in overcoming the overloading and desensitization of conventional communication equipment due to interference from high-powered pulse-type equipment, such as radar. This device was designed to permit the suppression of the pulse interference directly at the input terminals to a communication receiver without any internal modification. The blanker uses the gating technique with (1) the receiver turned off for the duration of each interfering pulse and turned on again by the pulses, and (2) the input signal at a rate high enough to reconstruct all the essential information in the desired signal from the knowledge of the samples alone. Results indicated the need for a switch which can be controlled by the blanking pulses to effect a rapid disconnection of the receiver from its antenna so as to prevent interfering pulses from entering the receiver. The switch must be capable of a very low minimum insertion loss so as not to unduly attenuate low-level desired signals. This blanker is concluded to be excellent in protecting the equipment from pulse interference.