General Electric Company

Gec-marconi Limited

David Francis Howell

Neil A Cade

A high-speed field emission vacuum switching device comprises a cathode tip formed on a substrate, an extraction grid close to the cathode tip, and a modulator grid spaced from the cathode tip by a dielectric layer. The grids have apertures aligned with the cathode tip. An anode is spaced from the modulator grid by a dielectric layer. By use of the modulator grid, a substantial improvement in high-frequency switching performance can be achieved. A collector grid may be provided between the extraction grid and the modulator grid, and a cut-off grid may be disposed between the modulator and collector grids.

Electronic switching devices

A klystron device comprises an array of cold-cathode field emission elements arranged to form a distributed amplifier which further comprises a modulation strip line and a catcher strip line. A collector electrode is spaced from the catcher strip line. The device may include a deflector for returning electrons emitted by the elements back to the modulation strip line so that the device acts as an oscillator.

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Maidenhead, United Kingdom

David Francis Howell