Abstract: An optically tunable cavity for an electronic device concurrently achieves high bandwidth (for example, at least about 10 percent, typically greater than about 50 percent) with high DC-RF efficiency (for example, at least about 50 percent, typically greater than about 85 percent). The electronic device may be a vacuum electronic device, including linear-beam and cross-field devices, with either an input circuit or an output circuit, or both, containing a photocapacitance-controlled resonator embedded such that a laser beam can impinge upon a semiconductor gap of the resonator. The laser beam may instantaneously change the resonant mode of the overall loaded cavity, thus allowing for amplification or oscillation of the desired frequency throughout the vacuum electronic device.

Abstract: A microwave system for driving a linear accelerator is provided. The inventive microwave system employs a plurality of magnetrons, at least one pulse generator to energize the magnetrons, means for synchronizing outputs from the magnetrons, and at least one waveguide for transmitting synchronized outputs or power from the magnetrons to a linear accelerator. The linear accelerator that is driven by the inventive microwave system demonstrates increased efficiency and dependability, higher energy and power outputs, as well as, different energy outputs that can take the form of successive pulses that alternate between at least two different energy levels.

Abstract: A power supply apparatus for a traveling-wave tube includes an electrical discharge switch and a first resistor that are serially connected, and that are connected between a cathode electrode and a first collector electrode; N (N denotes a positive integer) arresters that are serially connected, and that are inserted between a ground potential and a connection node of the electrical discharge switch and the first resistor; N second resistors that are inserted between the N arresters and a second collector electrode to an Nth collector electrode and a ground potential, respectively; and an electrical discharge control circuit that turns off the electrical discharge switch at a time of normal operation of the power supply apparatus and turns on the electrical discharge switch when stopping operation of the power supply apparatus.

Abstract: The invention relates to a microwave tube comprising an electron gun generating an electron beam in a cylindrical microwave structure of the tube. The microwave structure delivers a microwave at one output. A collector for collecting electrons from the beam comprising at least one electrode that is mechanically coupled to the microwave structure via a dielectric, the mechanical coupling forming a radial waveguide for propagating spurious microwave radiation (Pr) from the tube. In order to attenuate the spurious radiation from the tube, the radial waveguide (Wg) includes at least one quarter-wave microwave trap having, at least at the operating frequency F of the tube, an open circuit for the microwave propagating in said radial waveguide for propagating spurious radiation.

Abstract: A klystron has a plurality of electron beam paths and plural damped disc-shaped cavities. The plurality of electron beam paths cut the cavities and the Klystron amplifier further comprises an annular input cavity and an annular output cavity disposed around the substantially circular external periphery of respective disc-shaped cavities, and in communication with it. The output cavity is arranged to receive RF power from the electron beams, wherein the cavities are arranged to support one of a single resonant rotating wave in a whispering-gallery mode, and a single resonant standing wave in a whispering-gallery mode.

Abstract: A re-entrant resonant cavity 12 includes three parts 18, 19 and 20 which may be manufactured as metallized plastic components. The three parts 18, 19 and 20 are soldered to a multilayer PCB 23 using surface mount technology. The re-entrant stub 16 is in two portions with dielectric material provided by the PCB 23 between them. The cylindrical wall 13 surrounding the stub 16 is also divided into two sections 21 and 22 by the PCB 23. Vias 24 and 25 electrically connect the parts separated by the PCB 23. The pattern of the vias 24 and 25 determines the inductance of the cavity, and hence its resonance frequency. This enables cavities with the same geometry to be operated at different resonance frequencies by using different configurations of through connects. One of the sets of vias may be omitted in some cavities.

Abstract: An electromagnetic wave generating device includes: a hollow annular vacuum chamber; an electron gun; an electromagnet configured with a pair of discoid combinations in which a cylindrical accelerating magnet pole and an annular focusing magnet pole are arranged in this order from the inner side to the outer side of the combinations, and are disposed symmetrically and concentrically with each other on both sides of the chamber and coaxially with the center axis of the chamber, and a return yoke disposed outside both accelerating and focusing magnet poles and the chamber; accelerating coils wound around the accelerating magnet poles, for exciting the poles; and focusing coils wound around the focusing magnet poles, for exciting the poles; wherein a through hole is formed at the center of the accelerating magnet pole so that power supply wires connecting the accelerating coils to an accelerating power supply are led out through the hole.

Abstract: The interaction structure with integral coupling and bunching section and method of use of the present invention produces backward wave oscillations in an RF structure which combines ballistic bunching and extended beam-wave interaction in a complex resonator assembly. The complex extended interaction structure includes a five-gap electromagnetically-coupled cavity structure with a coaxial section inserted between the first and second cavities. The first cavity serves as a buncher cavity while the four subsequent cavities serve as energy cavities. In the coaxial section, beam and wave propagate in separate channels. The field in the buncher cavity is coupled to the four subsequent energy extraction cavities through the wave channel between the inner and outer conductors of the coaxial section, while the electron beam drifts along a cylindrical channel cut through the inner conductor of the coaxial section.

Abstract: A frequency tuning device for a microwave tube. The tube has one or more resonant cavities which are tuned with the aid of a movable tuning element for each cavity. Each tuning element has an actuating device and a sensor which detects the position of the tuning element. An electronic control is provided for comparing the position of the tuning element supplied by the sensor with a set position and for delivering a control signal to the actuating device which moves the tuning element to the set position.

Abstract: In a magnetically insulated line oscillator device having a cathode 11, a surrounding slow wave structure 15 has a tapered configuration so that the effective cavity depth in the slow wave structure 15 progressively diminishes along a part of the length of the device towards the power output end of the device.

Abstract: A four cavity, efficient magnetically insulated line oscillator (C4-E MILO) having seven vanes and six cavities formed within a tube-like structure surrounding a cathode. The C4-E MILO has a primary slow wave structure which is comprised of four vanes and the four cavities located near a microwave exit end of the tube-like structure. The primary slow wave structure is the four cavity (C4) portion of the magnetically insulated line oscillator (MILO). An RF choke is provided which is comprised of three of the vanes and two of the cavities. The RF choke is located near a pulsed power source portion of the tube-like structure surrounding the cathode. The RF choke increases feedback in the primary slow wave structure, prevents microwaves generated in the primary slow wave structure from propagating towards the pulsed power source and modifies downstream electron current so as to enhance microwave power generation.

Abstract: Conversion of electron beam energy into high power microwave energy is efted within the cavity of a Klystron device to which the electron beam is accelerated from a continuous supply source through an ion focussing channel. Ion focussing is achieved by establishment of a preionized background plasma within the channel to modulate the current of the electron beam in response to wake field effects and cause bunching of the electron beam during propagation to the Klystron device.

Abstract: 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.

Abstract: A band selector for a klystron includes a cam carrier and a plurality of cam followers. The cam carrier includes a plurality of cams with the cams being arranged in a plurality of rows. Each of the cam followers has a first end adapted to be mounted to a respective one of the plungers in the klystron and a second end. The cam carrier is positionable so that a selected one of the rows aligns with the cam followers. The cam followers are normally biased so that the second end of the cam followers abuts a respective one of the cams. The band selector further includes a first member movable between a first position and a second position. When the first member is in the first position, it is non-interactive with the cam followers. When the first member is moved to its second position, it becomes engageable with the first end of each of the cam followers to remove the second end of the cam followers from abutment with the respective one of the cams.

Abstract: A gyroklystron device includes an electron beam source, a plurality of bunching cavities and an output cavity. A first bunching cavity has an input coupling aperture for receiving an rf signal from an rf signal injecting source. Each of the bunching cavities has a first pair of substantially uniform-angle slots of a preselected angle, which are diametrically opposed, and extend axially, parallel to the direction of the electron beam and extend into drift regions on both sides of the cavities. The first pair of slots control the Q of a desired mode and higher order modes. A second and third pair of slots are diametrically opposed and extend axially, parallel to the direction of the first pair of slots, but are rotated 90 degrees circumferentially from the first pair of slots. These slots control the axial profile of any mode that leaks out beyond the desired mode and control the length of field interaction with the electron beam.

Abstract: Stabilizing a signal generating source by coupling a small amount of the output power through a bandpass filter tuned to the desired frequency and injecting the power back into the source. In another embodiment the filtered power may be increased by injection locking a smaller oscillator and using the output to stabilize the source, or the filtered power may be amplified in a reflection amplifier and injected into the source for stabilization.

Abstract: There is provided a high performance extended interaction output circuit [EIOC] having two cavities. The EIOC of the present invention has an image impedance which is twice the magnitude of its output load resistance. The EIOC of the present invention also includes a three cavity EIOC which has two image impedances, the second image impedance being one half the magnitude of the first image impedance while the output load impedance of the three cavity EIOC is one third the magnitude of the first image impedance.

Abstract: A klystron comprises a plurality of resonant cavities, the frequency of which is defined by a piston within each cavity. In order to change the frequency of the klystron, each piston is provided with a rod applied against an adjusting screw under the pressure of a spring. In order to reduce the bulk of the springs, the distance between a screw head and the plate on which the springs are applied remains constant irrespective of the length of the adjusting screws. This is obtained by means of a set of switches which are fixed on the movable plate and control the compression of the springs by checking the position of a cup in which each spring exerts its force on the corresponding piston rod.

Abstract: A processor-controlled drive motor system for tuning a cavity klystron monitors the output (amplitude-vs-frequency) of the klystron and compares that monitored performance output with an intended amplitude-vs-frequency profile. Differences between the two characteristics are employed by the processor to generate a set of tuning cavity control signals through which respective stepping motors for displacing each cavity tuning slug are driven. The processor iteratively adjusts the cavity tuner control signals in accordance with a prescribed kylstron tuning program until the monitored amplitude response is within a prescribed tolerance of a preestablished characteristic stored in memory.

Abstract: A tuning structure for a klystron oscillator is provided by a set of holes extending part way through cavity walls of the klystron. The holes provide weakened portions in the cavity walls which permit an inward depression of the walls at the sites of the weakened portions for adjustment of the central frequency of an oscillation band. Thereby, deformable tuning diaphragms, which are employed for altering the oscillation frequency within the oscillation band, need not be deformed for an oscillation at the center of the desired band. Variations in frequency can thereby be accomplished without metal fatigue, such fatigue having occurred when the diaphragm has been utilized for setting the central frequency of the oscillation band.

Abstract: A cylinder or barrel fitted with cams is used to limit the outward movement of spring-loaded plungers attached to cavity shorting bars in a klystron. Different tunings of the klystron are achieved by rotating the cylinder so that different rows of cams limit the plungers. A linear solenoid is used to decouple the plungers from the cams before rotation. A stepping solenoid is used to move the cylinder from one setting to another.

Abstract: In a gyro-monotron oscillator a single, "monotron" cavity is used to interact with the electron beam. To handle very high powers without excessive cavity loss, the cavity is excited in a higher order mode such as TE.sub.0m1. Other modes can be resonant in the cavity, interfering with the operation when their frequency is near the operating frequency.To increase the mode separation, an upstream section of the cavity is made smaller, to support only a lower-order mode such as TE.sub.011. Also, the beam is pre-bunched by this lower order, interference-free mode so has less tendency to interact with spurious modes in the higher order cavity.

Abstract: A klystron tuning control system has a D.C. motor which is connected to the tuning shaft of the klystron. The position of the tuning shaft is detected electrically and used to control the turning of the D.C. motor in order to reduce to zero a difference between the output voltage of the detecting means and a reference voltage. At zero, a coincidence signal is produced so that a counter means may count a predetermined number and provide an output responsive to which the D.C. motor is operated in only a predetermined direction for a short period of time.

Abstract: A klystron oscillator has an input cavity resonant in a TM.sub.010 mode and a larger output cavity resonant in a TM.sub.OnO mode where n is an integer greater than 1, preferably equal to 2. The input cavity, with re-entrant bosses defining a buncher gap, projects into the output cavity to form one of two re-entrant bosses thereof defining a catcher gap.

Abstract: A multi-cavity klystron device having a plurality of resonance cavities, comprising a plurality of movable elements, each of which is mounted on each of said resonance cavities and which is adapted to change the resonance frequency in each cavity, a plurality of tuning means for giving a reciprocal movement to each movable element against a resilient member provided therefor, a plurality of pulse motors coupled to the tuning means, and a preset means for controlling pulse supply to each pulse motor, wherein a predetermined number of pulses stored in the memory units of the preset means are selectively applied to the pulse motors to rotate each pulse motor in correspondence with the number of pulses, thereby changing each resonance frequency of each cavity.

Abstract: A self-exciting oscillator comprises a klystron with an input cavity and an output cavity, interconnected by a feedback port, which resonate at fractionally different frequencies in the microwave range. The output cavity, alone, is tunable to vary the operating frequency within a range of about .+-.2%.