Robert Boschgmbh

Agence Spatiale Europeenne

Tesat-spacecom Gmbh & Co Kg

Dietmar Schmitt

Franz-Josef Goertz

Dieter Wolk

Juergen Damaschke

Uwe Rosenberg

Marco Guglielmi

Wolfgang Hauth

David Raboso Garcia-Baquero

Jaime Hueso Gonzalez

Mario Sorolla

Javier Gil

Noelia Ortiz Perez De Eulate

Jaime Huesco Gonzalez

The invention concerns a waveguide filter () for microwaves, characterized in that it has, at least on part of its length, a cross-section having two mutually non-parallel opposite sides ('), for example trapezoid. The use of such a shape enables the power threshold for forming self-maintained electron avalanche discharges to substantially increased and satisfactory filtering properties to be obtained. The invention also concerns the use of such a filter in a high-power microwave transmitter operating in X and Ka bands, in particular for space applications.

Microwave waveguide filter with non-parallel walls

A microwave bandstop filter comprises a waveguide segment of cross-section that presents longitudinal variation of sinusoidal type modulated by an amplitude function that is continuous, the period of said longitudinal variation of sinusoidal type being the Bragg period for the fundamental guided mode at a center frequency of the band to be stopped. A filter assembly comprises a microwave lowpass filter presenting a cutoff frequency and at least one interfering passband at frequencies higher than said cutoff frequency, and at least one bandstop filter as defined above, connected to the output of said lowpass filter, in which the amplitude and the period of said longitudinal variation, and also the length over which it extends are such that they stop said interfering passband of said lowpass filter. An output multiplexer for a multichannel microwave transmitter includes such a filter assembly.

Microwave bandstop filter for an output multiplexer

A method and an arrangement for temperature compensation at circular resonators with dual mode utilization, which includes a material with a low coefficient of thermal expansion and for which the tensile or compressive forces are transferred to the resonator wall and produce elastic deformations there. The resonator wall is deformed in two mutually perpendicular directions in each case by the same absolute amount at one or more places along the axial e extent, the deformation forces being introduced into the resonator war over at least one flange. This has the advantage that the peripheral shape of the casing of the circular resonator is deformed so that both orthogonal dual modes experience uniform shortening with simultaneous expansion of the material, as a result of which a high compensation effect is achieved.

Method and device for compensating the temperature of circular resonators

For fixing a dielectric insert in a waveguide, clamping bodies are provided which contact the dielectric insert on its outer periphery only tangentially. The dielectric insert is fixed in a wave propagation direction by a supporting element. In a further embodiment, the dielectric insert is rigidly mounted on the supporting element. As a result thermal stresses can be absorbed.

Waveguide resonator device and filter structure provided therewith

A waveguide arrangement for microwaves and the like has a first waveguide composed of a material having a first thermal expansion coefficient, a second waveguide composed of a material having a second thermal expansion coefficient which is different from the first thermal expansion coefficient, and a transition element provided between the first and second waveguides for mechanical uncoupling of the different thermal expansion coefficients of both the waveguides.

Frequency-stabilized waveguide arrangement

A waveguide filter having a stepped transformer area on the input and/or output sides, with at least one band-stop filter composed of geometrically closely spaced stop elements integrated into this stepped transformer area. These features make it possible to build waveguide filters with a high edge steepness and a short overall length.

Waveguide filter

A microwave filter has at least two resonators, with at least two degenerated wave types resonance-capable in one resonator. The resonators are in operative connection with one another so that possible couplings of the degenerated wave types are only overcouplings and these overcouplings are located outside the resonator in which the two degenerated wave types are resonance-capable. As a result, the microwave filter has higher quality, improved selection properties and optimal polarization adapation.

Microwave filter with means for coupling degenerate modes

In a dielectric resonator a dielectric insert is formed so that at least two slots are provided, which are located opposite to one another and extend symmetrically and radially toward a center. Because of the radial slots, a dielectric resonator with high mode distance and high quality is obtained.

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Wassenaar, Netherlands

Dietmar Schmitt