A filter device includes first to third resonators. Each of the first to third resonators includes a first line part and a second line part electrically connected to the first line part and having an impedance smaller than an impedance of the first line part. The impedance ratio in at least one of the first to third resonators is 0.3 or smaller. The shape of each of the second line part of the first resonator and the second line part of the second resonator is long in a direction orthogonal to a stacking direction and crossing the longitudinal direction of the second line part of the third resonator.

A filter device includes first to third resonators. Each of the first to third resonators includes a first line part and a second line part electrically connected to the first line part and having an impedance smaller than an impedance of the first line part. The impedance ratio in at least one of the first to third resonators is 0.3 or smaller. The shape of each of the second line part of the first resonator and the second line part of the second resonator is long in a direction orthogonal to a stacking direction and crossing the longitudinal direction of the second line part of the third resonator.

A method of fabricating and tuning a surface integrated waveguide (SIW) filter incudes covering upper and lower surfaces of a dielectric substrate with a metallic layer. The method includes drilling a plurality of vias on the dielectric substrate and covering the vias with the metallic layer, wherein a first group of vias forms one or more cavity resonators, a second group of vias defines coupling channels between the cavity resonators, a third group of vias defines an effective width and a fourth group of vias defines an effective length of the cavity resonators. The method includes varying a center frequency by increasing diameters of the second group of vias to decrease the width of the coupling channels and varying a roll-off by increasing diameters of the third and fourth groups of vias to decrease the effective width and the effective length of the resonators.

A dual-band filtering switch based on a single quad-mode dielectric resonator (DR) includes: a first printed circuit board (PCB) provided thereon with an input terminal; a second PCB provided thereon with an output terminal; a shielding shell arranged between the first and second PCBs and enclosing a shielding cavity together with the first and second PCBs; and a single quad-mode DR arranged in the shielding cavity. The first and second PCBs each include a feeding layer, a dielectric layer, and a ground layer that are stacked in sequence. The feeding layers of the first and second PCBs each include a microstrip line and a switching circuitry connected to the microstrip line, and the feeding layer is in contact with a surface of the DR to realize a switching function of the filtering switch. The proposed filtering switch feature low loss transmission and high selectivity with dual-band operation, miniaturization with the fewest resonators and friendly-integration, simultaneously.

A dual-band filtering switch based on a single quad-mode dielectric resonator (DR) includes: a first printed circuit board (PCB) provided thereon with an input terminal; a second PCB provided thereon with an output terminal; a shielding shell arranged between the first and second PCBs and enclosing a shielding cavity together with the first and second PCBs; and a single quad-mode DR arranged in the shielding cavity. The first and second PCBs each include a feeding layer, a dielectric layer, and a ground layer that are stacked in sequence. The feeding layers of the first and second PCBs each include a microstrip line and a switching circuitry connected to the microstrip line, and the feeding layer is in contact with a surface of the DR to realize a switching function of the filtering switch. The proposed filtering switch feature low loss transmission and high selectivity with dual-band operation, miniaturization with the fewest resonators and friendly-integration, simultaneously.

The present invention provides target devices such as filter units with a plurality of external projection members that project outwardly from the target device and cooperate with apertures in a mounting bracket whereby the target device can be slidably moved from a first position to a second position provided by a lobe of the apertures to couple the target device to a respective support structure using a respective mounting bracket. The mounting bracket can be provided as a plurality of mounting brackets, including a first one attached to the support structure and a first side of a first target device and a second one attached to a second side of the first target device and to a first side of a second target device thereby allowing the first and second target devices to be stacked together to a common support structure.

The present invention provides target devices such as filter units with a plurality of external projection members that project outwardly from the target device and cooperate with apertures in a mounting bracket whereby the target device can be slidably moved from a first position to a second position provided by a lobe of the apertures to couple the target device to a respective support structure using a respective mounting bracket. The mounting bracket can be provided as a plurality of mounting brackets, including a first one attached to the support structure and a first side of a first target device and a second one attached to a second side of the first target device and to a first side of a second target device thereby allowing the first and second target devices to be stacked together to a common support structure.

Provided is a photonic crystal element, which shows small delay of an electric signal, shows a small propagation loss, and has uniform characteristics over its entirety. The photonic crystal element includes a two-dimensional photonic crystal slab having holes periodically formed in a substrate made of a ceramics material, the photonic crystal element being configured to guide an electromagnetic wave having a frequency of 30 GHz or more and 20 THz or less.

Disclosed is a ridge guide waveguide including a conductive base, a conductive ridge protruding upward from the conductive base and extending along a predetermined wave transmission direction, an upper conductive wall located over the conductive base and the conductive ridge and spaced apart from the conductive ridge by a gap, and an electromagnetic bandgap structure arranged adjacent to the conductive ridge between the conductive base and the upper conductive wall.

Disclosed is a ridge guide waveguide including a conductive base, a conductive ridge protruding upward from the conductive base and extending along a predetermined wave transmission direction, an upper conductive wall located over the conductive base and the conductive ridge and spaced apart from the conductive ridge by a gap, and an electromagnetic bandgap structure arranged adjacent to the conductive ridge between the conductive base and the upper conductive wall.