Abstract: The disclosed multipactor device has a waveguide bandpass filter structure including a plurality of spaced pairs of opposing electrodes defining respective gaps therebetween in which multipactor action can occur in response to input microwave power in excess of a predetermined level. A radioactive source of beta particles provides electrons within the bandpass filter structure to ensure a very rapid commencement of multipactor action. The radioactive source includes a disk coated with a tritium compound and mounted in a transverse bore adjacent to the bandpass filter structure.

Abstract: Stabilized air-oxidized chromium films deposited on high-power klystron ceramic windows and sleeves having a thickness between 20 and 150.ANG. are useful in lowering secondary electron emission yield and in avoiding multipactoring and window failure due to overheating. The ceramic substrate for the film is chosen from alumina, sapphire or beryllium oxide.

Abstract: A resonant cavity device--particularly a magnetron oscillator--has a separate resonator coupled to a resonant cavity of the device. The separate resonator consists of a resonant transmission line within which are two multipactor discharge arrangements, one being positioned at a distance along a resonant transmission line which is approximately 3.lambda./4 from the end of the transmission line adjacent the cathode and the other of which is positioned at a distance along the resonant transmission line which is .lambda./4 from the same end of the transmission line. By controlling the multipactor discharges of the multipactor discharge devices appropriately three different frequencies of operation are available.

Abstract: A plurality of contiguous cavity pairs of multipactor input and output cavities respectively formed in two opposing ridge waveguide sections and which are mutually separated by an acceleration drift region of relatively high DC electric field strength. Both waveguide sections include means such as an RF window at one end for coupling RF power in and out of the sections while the other end is suitably terminated and additionally provides the structure which can be placed under a vacuum to properly function. The cavity pairs are arranged in a linear array subassembly within each of the waveguides and are designed to have a broadband frequency response by progressively increasing in frequency so that half power points of contiguous cavity pairs are in close proximity.

Abstract: In an RF/microwave component such as a resonator, multipacting is eliminated in accordance with the present invention by rectifying a portion of the RF signal present within the component to derive a dc potential. This dc potential is used to bias the component so as to the prevent polarity reversal across the component electrodes, thereby to eliminate multipacting without the use of an external bias supply.

Abstract: A frequency multiplier for electromagnetic waves in which multiples of the input frequency propagate, while the input frequency evanesces. A rectangular waveguide or other suitable wave conveying element with a cut-off frequency above the input frequency but below the output frequency contains the multiplying structure. The input frequency is multiplied using a post located in the waveguide or other element adjacent to the source of input waves. The post may define a multiplier gap between one of its surfaces and a wall of the waveguide or other element, in which case the multiplier gap may contain a multipactor between its surfaces which generates multiples of the input frequency. The multiplier gap may alternatively contain a non-linear element responsive to a high electric field, such as a ferroelectric material, which also generates multiples of the input frequency. Alternatively, the post may be surrounded by a non-linear element of ferromagnetic material responsive to a strong magnetic field.

Abstract: A multipactor discharge tuned resonant cavity device, e.g. a magnetron, is irradiated with X-rays in order to assist the starting of the multipactor discharge. The X-rays are produced by electrons striking the surface of the magnetron anode.

Abstract: A microwave discharge gap receiver protector includes a radioactive ignitor of the nuclear decay type to provide an auxiliary source of electron priming therefore, the radioactive ignitor comprising a radioactive plate for emitting beta particles therefrom, and a tubular enclosure to channel the flow of emitted beta particles therethrough. In operation, a portion of the channeled emitted beta particles collide with the inner walls of the enclosure which are comprised of a material having a high secondary emission characteristic to generate additional electron particles as a result of secondary emission. Another portion of the beta particles in the channel of the tubular enclosure collide with existing gas particles to generate a second source of auxiliary electrons. The combined sources of auxiliary electrons result in an increased particle concentration which is emitted at an exit end of the enclosure and directed to the discharge gap of the receiver for priming purposes.

Abstract: The specification describes a vacuum device utilizing the multipacting phenomenon in a special insulated-electrode microwave comb-line structure and functioning as a high speed, single pole, single throw, RF switch with the exception that in the off condition, power is absorbed in the device.

Abstract: A resonant cavity such as a diplexer filter and a coaxial resonator, for example, wherein its interior resonant cavity structure is packed with a powdered polytetrafluoroethylene material to prevent arcing within the resonant cavity structure due to the multipacting phenomenon.

Abstract: In a vane type magnetron oscillator a resonant co-axial transmission line breaks through the wall of the anode block to couple to two adjacent cavities on either side of a vane. Positioned at a point at which a high radio frequency voltage appears in operation approximately an odd multiple of a quarter wavelength (preferably 3.lambda./4) from the end of the transmission line adjacent the cavities is a multipactor discharge arrangement. This latter consists of two co-axial cylinders one connected to the inner conductor and the other to the outer conductor of said transmission line. The transmission line extends beyond the multipactor discharge arrangement to a total length approximately half wavelength or a multiple thereof and is short circuited at its end.

Abstract: A multipactor discharge tuned resonant cavity device, e.g. a magnetron, is arranged with two multipactor discharge electrodes so that in a discharge condition a net current flows from one electrode to the other. The net current is used to create a self-bias voltage on one of the electrodes which affects the operating frequency of the device.

Abstract: This invention relates to a co-axial magnetron in which a separate resonator incorporating a multipactor discharge arrangement is used to tune the operating frequency of the magnetron. The separate resonator is symmetrically coupled via couplers into the main resonator cavity of the magnetron. More than one separate resonant can be provided, in which case they are symmetrically coupled into the main resonant cavity to achieve correct tuning.

Abstract: A device for providing a tunable impedance due to variations of a multipactor discharge; the device of the invention gives rise to low insertion losses when incorporated in another device, due to particular structure provides a longitudinal drift of the electrons of the discharge which thus have an elongated trajectory before stricking an electrode.

Abstract: Cavity resonator electronic tubes, in particular magnetrons, with an electronic tuning system. The tuning systems in accordance with the invention consist of multipactor elements arranged directly within the resonant volumes of the tube cavities. Frequency tuning can be effected either by switching between two predetermined frequencies or by continuous change of the frequency.