Abstract: A digital, open-loop, sidelobe canceller system includes an arrangement of uxiliary-channel preprocessing cancellers and a series of main-channel cancellers in which specific cancellers average a different number of samples for cancelling both barrage (continuous) jamming and false-target-repeater jamming, which enter the sidelobes of a radar antenna. The preprocessing cancellers and each of the main-channel cancellers, except the last succeeding main-channel canceller, use long-time averaging (averaging over a large number, n, of samples of the main and auxiliary signals, where n>>2) for removing barrage jamming from the main signal. The last succeeding main-channel canceller uses short-time averaging (averaging over approximately 2-4 samples) for removing false-target-repeater jamming from the main signal.

Abstract: 1. An electron-discharge device comprising: an evacuated envelope; a cold electrode supported within said envelope; a thermionic filamentary cathode; and means including at least one spring member affixed to said cathode and supported from said envelope for normally supporting said cathode in tension in a position within said envelope spaced from said cold electrode and adapted to relax said tension in response to rapid acceleration of said envelope in a predetermined direction perpendicular to said filamentary cathode, the space between said normal position of said cathode and the inner wall of said envelope being substantially unobstructed in a direction opposite to said predetermined direction whereby said cathode is supported by said wall throughout substantially its entire length when subjected to said acceleration.