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Publication of BE450801ApublicationCriticalpatent/BE450801A/xx
H01Q19/00—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic
H01Q19/10—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces
H01Q19/12—Combinations of primary active antenna elements and units with secondary devices, e.g. with quasi-optical devices, for giving the antenna a desired directional characteristic using reflecting surfaces wherein the surfaces are concave
E02B7/00—Barrages or weirs; Layout, construction, methods of, or devices for, making same
E02B7/02—Fixed barrages
E02B7/04—Dams across valleys
E02B7/08—Wall dams
E02B7/14—Buttress dams
H—ELECTRICITY
H01—ELECTRIC ELEMENTS
H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
H01J25/00—Transit-time tubes, e.g. klystrons, travelling-wave tubes, magnetrons
H01J25/02—Tubes with electron stream modulated in velocity or density in a modulator zone and thereafter giving up energy in an inducing zone, the zones being associated with one or more resonators
H01J25/06—Tubes having only one resonator, without reflection of the electron stream, and in which the modulation produced in the modulator zone is mainly velocity modulation, e.g. Lüdi-Klystron
H01J25/08—Tubes having only one resonator, without reflection of the electron stream, and in which the modulation produced in the modulator zone is mainly velocity modulation, e.g. Lüdi-Klystron with electron stream perpendicular to the axis of the resonator