Litton Systems, Inc.

Richard J Pasco

Chris L Wheeland

A crossed-field device comprises a cathode having an electron emitting surface and an anode structure radially spaced from the cathode. The anode structure has a plurality of vanes extending in radial directions of the cathode with an interaction region defined between the electron emitting surface of the cathode and innermost radial ends of the anode vanes. First and second magnetic polepieces are respectively disposed at first and second axial ends of the cathode and have respective magnets coupled magnetically thereto. The polepieces direct magnetic flux from the respective magnets to define an axial magnetic field through the interaction region. The polepieces are electrically isolated from the anode structure. An anode modulator is adapted to provide a voltage potential between the anode structure and the cathode to define a radial electric field through the interaction region. A polepiece modulator is adapted to provide a voltage potential between the polepieces to define an axial electric field through the interaction region, whereby a frequency characteristic of the crossed-field device is adjusted by varying the axial electric field.

Tertiary field tuning of positive anode magnetron

A crossed-field amplifier is provided having a cathode structure with an emitting surface which emits secondary electrons upon impingement of priming electrons, an anode vane structure surrounding the cathode and a signal input port located adjacent the anode vanes. A secondary emission material is disposed in an area proximate the signal input port for providing priming electrons in the interaction region of the amplifier. The RF input signal causes the secondary emission material to emit priming electrons for use by the cathode structure. The creation of priming electrons in the interaction area reduces irregular start-up or 'jitter' typically experienced with the amplifier at low pulse repetition frequencies.

Passive jitter reduction in crossed-field amplifier with secondary

A semiconductor diode is connected across the cathode-to-anode path of a magnetron and through a storage capacitor and collector resistor to a supply voltage for enabling charging of the capacitor. A control pulse causes a switching transistor to conduct to discharge the capacitor through its collector-to-emitter path, an emitter resistor, and the magnetron, for causing the latter to oscillate. A feedback signal representative of the difference between the magnetron output frequency and a reference frequency is applied to a linear amplifier transistor which conducts through the emitter resistor for controlling the current flow through the switching transistor and the operating frequency of the magnetron.

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South Williamsport, PA, United States of America

Richard J Pasco