A dielectric waveguide filter includes first resonant cavities, which are connected to form upper resonant cavities, and second resonant cavities, which are connected to form lower resonant cavities, wherein the upper and lower resonant cavities are correspondingly overlapped; each of the first resonant cavities has a first window coupling structure, wherein the first window coupling structure includes a first window opened at a position where the magnetic field distribution of a high-order mode in each of the first resonant cavities is the weakest, and/or a second window opened at a position where the electric field distribution of the high-order mode in each of the first resonant cavities is the strongest; and each of the second resonant cavities has a second window coupling structure corresponding to the first window coupling structure, and the first and second window coupling structures cooperate to eliminate the high-order modes of the dielectric waveguide filter.

A test article described herein enables ground-based arc jet testing to investigate RF blackout mitigation using electrophilic gas injection upstream of an antenna. The article can be scaled up to actual flight vehicles, thereby allowing reentry vehicles to be in constant, or near constant, communication during atmospheric reentry. Plasma blackout mitigation is an enabling technology that is required to advance hypersonic flight. Example articles include an integral structure that supports a nozzle, piping for gas connected to the nozzle and an RF window. An ablator can be attached to the structure. The ablator can include a graphite ablator and an insulator. A flight vehicle can include an antenna and such an article.

A pillbox-type RF window having an input/output window in a microwave tube, the pillbox-type RF window includes a disc-shaped member having a metallization layer formed on an outer peripheral portion of a disc-shaped ceramic body; a pair of ring-shaped members constituted by metal bodies having substantially the same outer diameters as the disc-shaped member, arranged to sandwich the disc-shaped member from both sides, and integrated with the outer peripheral portion of the disc-shaped member; a tube-shaped member constituted by a metal body having an inner diameter substantially equal to the outer diameters of the pair of ring-shaped members and the disc-shaped member, for holding the pair of metal components and the disc-shaped member on an inside thereof; and a restriction member for suppressing rotation between the ring-shaped members and the tube-shaped member.

A pillbox-type RF window having an input/output window in a microwave tube, the pillbox-type RF window includes a disc-shaped member having a metallization layer formed on an outer peripheral portion of a disc-shaped ceramic body; a pair of ring-shaped members constituted by metal bodies having substantially the same outer diameters as the disc-shaped member, arranged to sandwich the disc-shaped member from both sides, and integrated with the outer peripheral portion of the disc-shaped member; a tube-shaped member constituted by a metal body having an inner diameter substantially equal to the outer diameters of the pair of ring-shaped members and the disc-shaped member, for holding the pair of metal components and the disc-shaped member on an inside thereof; and a restriction member for suppressing rotation between the ring-shaped members and the tube-shaped member.

Tunable cavity waveguides are disclosed. In certain embodiments, a tunable cavity waveguide includes a controllable tunnel structure including a signal feed configured to receive a millimeter wave signal, and a plurality of controllable tunnel walls providing a waveguide for the millimeter wave signal. The unable cavity waveguide further includes a control circuit configured to control the waveguide by individually setting each of the plurality of controllable tunnel walls in a blocking state in which the millimeter wave signal is blocked or a transparent state in which the millimeter wave signal is passed.

Tunable cavity waveguides are disclosed. In certain embodiments, a tunable cavity waveguide includes a controllable tunnel structure including a signal feed configured to receive a millimeter wave signal, and a plurality of controllable tunnel walls providing a waveguide for the millimeter wave signal. The unable cavity waveguide further includes a control circuit configured to control the waveguide by individually setting each of the plurality of controllable tunnel walls in a blocking state in which the millimeter wave signal is blocked or a transparent state in which the millimeter wave signal is passed.

The present disclosure relates to a multi-type filter, and in particular, to a multi-type filter comprising: a cavity filter provided in any one (hereinafter, referred to as a “reference cavity”) among a plurality of cavities formed in a housing to be open to one side; and dielectric resonator filters respectively provided in at least two cavities adjacent to the reference cavity (hereinafter, referred to as “adjacent cavities”), wherein, to control the notch characteristics between the cavity filter and the at least two dielectric resonator filters according to windows formed by cutting of portions of partition walls between the reference cavity and the adjacent cavities to be in communication with each other, the windows are provided at different positions, which is advantageous in that the cross-coupling design is very easy without the need to include a metal crossbar and the like for separate notch formation.

The present disclosure relates to a multi-type filter, and in particular, to a multi-type filter comprising: a cavity filter provided in any one (hereinafter, referred to as a “reference cavity”) among a plurality of cavities formed in a housing to be open to one side; and dielectric resonator filters respectively provided in at least two cavities adjacent to the reference cavity (hereinafter, referred to as “adjacent cavities”), wherein, to control the notch characteristics between the cavity filter and the at least two dielectric resonator filters according to windows formed by cutting of portions of partition walls between the reference cavity and the adjacent cavities to be in communication with each other, the windows are provided at different positions, which is advantageous in that the cross-coupling design is very easy without the need to include a metal crossbar and the like for separate notch formation.

An invention comprises: a circular waveguide that has a cylindrical section having a circular pipe conduit with a circular shaped cross section, and side wall sections joined to the both sides in an axial direction of the cylindrical section; a first rectangular waveguide that has a first rectangular pipe conduit with a rectangular shaped cross section and that is joined to one of the side wall sections so that the first rectangular pipe conduit communicates with the circular pipe conduit; a second rectangular waveguide that has a second rectangular pipe conduit with a rectangular shaped cross section and that is joined to the other of the side wall sections so that the second rectangular pipe conduit communicates with the circular pipe conduit; and a dielectric plate that is configured as a plate shape, is disposed in the circular pipe conduit, and is airtightly held to the cylindrical section, wherein the circular waveguide has a plastically deformable section that is plastically deformable so that at least the length in an axial direction of the circular waveguide can be changed.

An invention comprises: a circular waveguide that has a cylindrical section having a circular pipe conduit with a circular shaped cross section, and side wall sections joined to the both sides in an axial direction of the cylindrical section; a first rectangular waveguide that has a first rectangular pipe conduit with a rectangular shaped cross section and that is joined to one of the side wall sections so that the first rectangular pipe conduit communicates with the circular pipe conduit; a second rectangular waveguide that has a second rectangular pipe conduit with a rectangular shaped cross section and that is joined to the other of the side wall sections so that the second rectangular pipe conduit communicates with the circular pipe conduit; and a dielectric plate that is configured as a plate shape, is disposed in the circular pipe conduit, and is airtightly held to the cylindrical section, wherein the circular waveguide has a plastically deformable section that is plastically deformable so that at least the length in an axial direction of the circular waveguide can be changed.