There is provided a substrate integrated waveguide filter having a central region and a peripheral region surrounding the central region, and including: a first substrate; a second substrate opposite to the first substrate; a plurality of conductive support pillars between the first substrate and the second substrate, within the peripheral region, and surrounding the central region, wherein a distance between at least one pair of adjacent two of the plurality of conductive support pillars is less than a wavelength of an electromagnetic wave to be transmitted by the substrate integrated waveguide filter; and a dielectric layer between the first substrate and the second substrate, wherein a permittivity of the dielectric layer is configured to be changed as a strength of an electric field formed between the first substrate and the second substrate is changed to adjust a frequency of the substrate integrated waveguide filter.

Apparatuses, methods, and systems for a housing structure for maintaining alignment between ceramic sections of a bandpass filter are disclosed. One housing structure includes an L-shaped outer structure, a plurality of flexure portions, wherein at least one of flexure portion extends from an end portion of each of extended arms of the L-shaped outer structure, wherein each flexure portion extends inward perpendicular to each of the extended end portion, and a plurality of reference datums, wherein at least one reference datum is located between an L-joint of the L-shaped outer structure, and a one of the flexure portions. The housing structure operates to receive a plurality of sections of a waveguide filter, wherein each section includes a plurality of planar surfaces, wherein the datums and the flexure portions are operative to maintain alignment of the sections of the waveguide filter relative to each other.

Waveguide cross sections designed for waveguide filters. An apparatus includes a waveguide cavity for propagating an electromagnetic signal, wherein the waveguide cavity is defined by a plurality of sidewalls. The waveguide cavity comprises an irregular hexagonal cross-sectional geometry that has a complex side, wherein the complex side comprises a first side and a second side connected to the first side, and wherein the first side and the second side of the complex side meet at a radiused edge.

An analog matching filter includes a first plate, a second plate coupled with the first plate and separated from the first plate via a spacer, and a replicate matching material fixed to an inside surface of the first plate. A conductive plate or sheet is fixed to an inside surface of the second plate. An electrical circuit connects the first plate to the conductive plate or sheet. The replicate matching material and the conductive plate or sheet generate an opposite polarization pattern carried by the electrical circuit that is based on a polarization pattern of a to-be-detected entity according to a spatial gradient of the to-be-detected entity local electric field distribution.

A filter for filtering an electromagnetic wave and a filter design method are provided. The filter comprises a cavity with a first plate and a second plate, the first and second plates are opposite to each other. The first plate comprises a number of elements distributed on the side of the first plate facing the cavity, wherein a location of each element on the first plate is defined in a coordinate system. The second plate comprises a number of elements distributed on the side of the second plate facing the cavity according to the locations of the elements on the first plate, wherein each element is distributed on the second plate with an offset with respect to a corresponding element on the first plate.

Filter devices are provided herein. In some embodiments, a filter device includes resonators and a cover that is attached by adhesive tape to a housing that includes the resonators. In some embodiments, the filter device includes a tuning cover that overlaps the resonators and has cleaning holes therein. Moreover, in some embodiments, the filter device includes a wall inside the housing between a first of the resonators and a second of the resonators, and an average thickness of the wall is 3.0 millimeters or thinner. Related methods of manufacturing filter devices are also provided.

A method for minimizing center frequency shift and linearity errors encountered in YIG filters, comprising the following steps: automatically generating data packages in test unit depending on the user request or containing all filter characteristic states and transmitting them to the driver circuit, adjusting the desired voltage level by means of the digital to analog converters contained in the structure of the data packages received by the driver circuit, and transmitting the adjusted voltage level to the YIG filter, measuring filter characteristics (scattering parameters) corresponding to the data packages transmitted to the YIG filter in the analyser, in order to calculate the center frequency shift of the filter, determining the center frequency and linearity calculations, and recording the characteristic features measured by the analyser in the test unit.

Methods and apparatus for providing a frequency selective limiters (FSL) having a free-standing Yttrium Iron Garnet (YIG) film with first and second opposing surfaces. A metal plane is disposed on one surface of the YIG film to provide the YIG film with a metalized surface. At least one transducer is disposed on the other surface of the YIG film with a respective ends coupled to the metalized surface of the YIG film.

The disclosed radio frequency (RF) bandpass filter may include an RF transmission medium that defines (1) a plurality of cavities aligned parallel to each other along a major axis, where (a) each cavity includes planar surfaces that define (i) a first dimension aligned with the major axis and (ii) second and third dimensions aligned perpendicular to the major axis and each other, where the first dimension is shorter than the second and third dimensions and (b) each adjacent pair of cavities is coupled by an inter-cavity slot, (2) an RF inlet that couples a received RF signal to a first cavity at a first end of the plurality of cavities, and (3) an RF outlet that couples a filtered RF signal from a second cavity at a second end of the plurality of cavities externally to the filter. Various other filters and manufacturing methods thereof are also disclosed.

The present disclosure provides a filter structure and a method for manufacturing a filter structure. The filter structure includes a metal resonant array. The metal resonant array includes a plurality of array units. The filter structure further includes a transparent plastic film. The metal resonant array is provided on the transparent plastic film.