A plane filter includes a dielectric substrate, a filter part provided on the dielectric substrate, and an input/output line connected to the filter part on the dielectric substrate. The filter part and the input/output line are provided on a front surface of the dielectric substrate. The dielectric substrate includes first and second regions. The filter part is provided in the first region, and the input/output line is provided in the second region. The first region having a first thickness in a first direction toward the front surface from a back surface at a side opposite to the front surface. The second region having a second thickness in the first direction, the second thickness being less than the first thickness. The back surface includes a step corresponding to a difference between the first thickness and the second thickness.

Embodiments disclosed herein include package substrates with filter architectures. In an embodiment, a package substrate comprises a core with a first surface and a second surface, and a filter embedded in the core. In an embodiment, the filter comprises a ground plane, where the ground plane is substantially orthogonal to the first surface of the core, and a resonator adjacent to the ground plane.

A package antenna apparatus including a package substrate, wherein an antenna array is disposed on the package substrate, and a transceiver chip coupled to the antenna array, where the transceiver chip is fastened to the package substrate, and the transceiver chip has a first pad and a second pad, and a filter disposed on the package substrate, where the filter comprises an input port and an output port, the input port is coupled to the first pad of the transceiver chip, the output port is coupled to the second pad of the transceiver chip, and the filter is configured to filter a signal of the transceiver chip that is input through the input port, and is further configured to output a filtered signal to the transceiver chip through the output port.

A filter includes first and second resonators and first and second stub resonators. Each of the first and second resonators includes a first conductor part and a second conductor part electrically connected to the first conductor part and having an impedance smaller than an impedance of the first conductor part. The first stub resonator is electrically connected to the first conductor part of the first resonator. The second stub resonator is electrically connected to the first conductor part of the second resonator. The shape of the first stub resonator and the shape of the second stub resonator are different from each other.

A compact planar balun formed on a substrate including a hairpin-shaped conductive microstrip and a single-ended contact. The hairpin-shaped conductive microstrip includes first and second linear segments integrally formed with a U-shaped segment, and a single-ended contact is conductively coupled at a location along the first linear segment. The first and second linear segments each have a first characteristic impedance and are in parallel with each other having a first end forming first and second differential contacts and having a second end. The U-shaped segment has a second characteristic impedance that is less than the first characteristic impedance in order to achieve proper scatter parameter alignment. The U-shaped segment may be generally formed thicker or wider than the linear segments to achieve a reduced characteristic impedance. In the alternative or in addition, co-planer ground metal is formed closer to the U-shaped segment to achieve a reduced characteristic impedance.

According to an embodiment, a filter characteristic tuning apparatus includes a characteristic tuning member, an elastic member, a first movable member, a second movable member, and a driving mechanism. The elastic member comes in contact with a characteristic tuning member by deformation, and separates from the characteristic tuning member by a restoring force. The first movable member deforms the elastic member in a closing operation. The driving mechanism displaces a second movable member such that a projection opens/closes the first movable member. The characteristic tuning member changes a gap between the characteristic tuning member and the resonator by a linear driving force obtained by converting the transmitted rotary driving force.

A high frequency, stripline filter may have a bottom surface for mounting to a mounting surface. The filter may include a monolithic base substrate having a top surface and a plurality of thin-film microstrips, including a first thin-film microstrip and a second thin-film microstrip, formed over the top surface of the substrate. Each of the plurality of thin-film microstrips may have a first arm, a second arm parallel to the first arm, and a base portion connected with the first and second arms. A port may be exposed along the bottom surface of the filter. A conductive path may include a via formed in the substrate. The conductive path may electrically connect the first thin-film microstrip with the port on the bottom surface of the filter. The filter may exhibit an insertion loss that is greater than −3.5 dB at a frequency that is greater than about 15 GHz.

Provided is a dual-band resonator which can be downsized further than conventional ones. A dual-band resonator is provided with a first conductor and a second conductor. The first conductor is configured to be folded at a first folding part at the center so that both extensions are in a prescribed direction and adjacent to one another with a prescribed space therebetween, wherein a conductor part closer to one end side than the first folding part and a conductor part closer to the other end side than the first folding part are further folded at second folding parts between the one end and the first folding part and between the other end and the first folding part, respectively, in a direction in which the one end and the other end are apart from each other. The second conductor extends in a prescribed direction contiguously to the first folding part of the first conductor. The first conductor constitutes a half-wavelength resonator, and odd-mode resonance occurs in the first conductor. The first conductor and the second conductor constitute a half-wavelength resonator, and even-mode resonance occurs in the first conductor and the second conductor.

A radio frequency passband filter is provided comprising a network of half-wavelength planar resonators. At least one of the half-wavelength planar resonators includes a resistor shunted to ground to flatten response in the passband.

A band-pass filter includes a first input/output port, a second input/output port, a plurality of resonators, and a multilayer stack. The multilayer stack includes a plurality of stacked dielectric layers. Each of the resonators is an open-ended resonator formed of a conductor line in the multilayer stack. Each of the resonators includes a resonator conductor portion including a first line part and a second line part located away from each other in a direction orthogonal to a stacking direction of the plurality of dielectric layers, and a third line part connecting the first line part and the second line part. The first to third line parts extend to surround a space between the first line part and the second line part.