Abstract: An electron beam tube (17) having a longitudinal axis comprises a first component, such as a ceramic wall (5) and a second component such as a drift tube assembly having a mounting plate (3). The tube further comprises means, such as member (18), arranged to allow relative sliding movement of the first component relative to the second component in a radial direction. The invention helps to alleviate mechanical stresses caused by differential thermal expansion of the components.

Abstract: A collector for an electron beam tube comprises a plurality of electrode stages. The electrode stages are spaced from one another by a non-conductive spacer. The non-conductive spacer is located between portions of electrodes and extends into the collector on a first side and out of the collector on a second side. The non-conductive spacer has an inner portion extending into the collector and an outer portion extending out of the collector and a waisted portion there between. The spacer is held at the waisted portion.

Abstract: A linear electron beam tube comprises an electron gun having a cathode and a grid, and an anode arranged in a first portion of a drift tube. The drift tube is within a vacuum envelope and has first and second portions separated by a gap at which point an electron beam, density modulated with an input RF signal is inductively coupled to an output cavity. The vacuum envelope is partially defined by a cylindrical ceramic wall and a pair of ferromagnetic pole pieces at its ends that form a DC magnetic circuit. The pole pieces extend radially beyond the vacuum envelope. At least those parts of the surface of the pole pieces that are in the RF path are coated with a layer of relatively low RF loss material such as copper. A balance ring separates the ceramic from the pole pieces.

Abstract: An electron beam tube (17) having a longitudinal axis comprises a first component, such as a ceramic wall (5) and a second component such as a drift tube assembly having a mounting plate (3). The tube further comprises means, such as member (18), arranged to allow relative sliding movement of the first component relative to the second component in a radial direction. The invention helps to alleviate mechanical stresses caused by differential thermal expansion of the components.

Abstract: A tuning door is fabricated for a resonant cavity of a high frequency apparatus. Contact fingers are formed around the edge of a conductive plate. The plate is then fixed to a support by, for example, double sided adhesive tape. The conductive plate is part of the interior surface of the resonant cavity. The fingers may be formed in one operation, for example, by photoetching and are fully integral with the active surface to give optimum electrical conduction between them. Other types of high frequency apparatus may use contact fingers to provide electrical conduction between a movable wall and an adjacent conductive surface.