Abstract: A ceramic waveguide filter, a radio unit, an antenna unit and a base station are disclosed. According to an embodiment, a ceramic waveguide filter comprises a body (1) that is made of a ceramic material and that has a plurality of resonators each including a blind hole (101). The blind holes (101) of two of the resonators open at a first surface of the body (1) and extend toward an opposite second surface of the body (1). Capacitive coupling between the two resonators is achieved by a coupling structure (201) on/in a substrate (2), to which the body (1) is attached at the side of the second surface.

Abstract: Provided is a process for manufacturing magnetically tunable nano-resonators. The nano-resonators comprise nanoparticles of a crystalline magnetic material embedded into cavities of a substrate.

Abstract: A dual mode notch filter for use in a multi-band millimeter wave (mmW) transmitter includes a transmit filter circuit disposed between two amplifiers in a mmW transmit signal path, the transmit filter circuit formed by at least one switch, at least one capacitor, and a double-tuned transformer, the transmit filter circuit having at least two modes configured to selectively filter a spurious signal in at least a first communication band.

Abstract: A communication network system is a communication network system that distributes information to a plurality of terminals inside a closed space. The communication network system includes a network server and a plurality of lighting fixtures each having an antenna that transmits and receives millimeter-wave-band communication signals to and from the terminals.

Abstract: Techniques regarding determining the temperature of one or more quantum computing devices are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a temperature component that can determine a temperature of a superconducting resonator based on a frequency shift exhibited by the superconducting resonator due to a change in kinetic inductance with a change in temperature.

Abstract: An assembly for a radio frequency filter includes: an elongate pedestal with an upper surface; a resonator; a tuning member that is positioned above the resonator; and a screw that mounts the resonator to the upper surface of the pedestal, the screw including a shank with a thread and a head, the head including a plurality of recesses configured to receive a tool, the recesses extending through the head.

Abstract: The present disclosure relates to an electronic device that includes a waveguide, a plurality of transceiving portions over the waveguide, and a cavity between the waveguide and the transceiving portions and connecting the waveguide with the transceiving portions. The cavity is configured for resonating of an electromagnetic wave from the waveguide or the transceiving portions.

Abstract: The present invention discloses a dielectric filter with multilayer resonator, including a dielectric block, a plurality of multilayer resonator formed in the dielectric block, wherein each multilayer resonator is in a column shape extending in a first direction into the dielectric block and is formed of multiple metal layers paralleling and overlapping each other in a second direction, and vias extend in the second direction and connecting the metal layers in each multilayer resonator, and a ground electrode connected to the ground terminal of each multilayer resonator.

Abstract: Disclosed are designs for inductor cores for electromagnetic interference (EMI) filters. In some embodiments, an inductor core comprises a plurality of enclosed structures, where each enclosed structure of the plurality of enclosed structures includes a plurality of elongated bars and at least one connection device. In some embodiments, an enclosed structure is configured to encompass a signal bus. In some embodiments, an enclosed structure has a longitudinal axis and a triangular cross-sectional shape taken perpendicular to the longitudinal axis.

Abstract: A balanced-type circular disk resonator includes a circular conductive layer, a conductive member including a first conductive portion provided on a first surface of the circular conductive layer to enable a first dielectric board, a dielectric property of which is measured, to be placed between the first conductive portion and the circular conductive layer, and a second conductive portion provided on a second surface of the circular conductive layer to enable a second dielectric board, a dielectric property of which is measured, to be placed between the second conductive portion and the circular conductive layer, the second surface being opposite to the first surface with regard to the circular conductive layer, and a temperature adjustment unit coupled to the conductive member and configured to adjust temperatures of the first conductive portion and the second conductive portion.

Abstract: Embodiments herein are directed to a resonator for an ion implanter. In some embodiments, a resonator may include a housing, and a first coil and a second coil partially disposed within the housing. Each of the first and second coils may include a first end including an opening for receiving an ion beam, and a central section extending helically about a central axis, wherein the central axis is parallel to a beamline of the ion beam, and wherein an inner side of the central section has a flattened surface.

Abstract: A filter has a first conductive layer, a second conductive layer, and a dielectric substrate located between the first conductive layer and the second conductive layer, wherein the dielectric substrate includes a waveguide capable of propagating a radio-frequency signal in a first direction by a region between a first conductive via group passing through the dielectric substrate from the first conductive layer to the second conductive layer and spaced apart from each other along the first direction and a second conductive via group passing through the dielectric substrate from the first conductive layer to the second conductive layer and spaced apart along the first direction, and a reflective resonator that is coupled to the waveguide in an electromagnetic field and reflects a signal in a predetermined frequency band in the radio-frequency signal propagating through the waveguide, and the reflective resonator has a third conductive via group and fourth conductive vias.

Abstract: Example dielectric filters, transceiver devices, and base stations are described. One example dielectric filter includes a dielectric block whose surface is covered with a metal layer, where the dielectric block includes at least two resonant cavities. The dielectric block is provided with a via hole, the via hole is located between two adjacent resonant cavities, and an inner wall of the via hole is covered with a metal layer. A first partition ring is disposed on the surface of the dielectric block and is surrounding at least one opening of the via hole, and the dielectric block is exposed in an area enclosed by an inner edge of the first partition ring and an outer edge of the first partition ring.

Abstract: Techniques regarding microwave-to-optical quantum transducers are provided. For example, one or more embodiments described herein can include an apparatus that can include a microwave resonator on a dielectric substrate and adjacent to an optical resonator, and a photon barrier structure at least partially surrounding an optical resonator, wherein the photon barrier structure is configured to provide isolation of the microwave resonator from optical photons in the dielectric substrate outside the photon barrier structure.

Abstract: RF co-designed bandpass filters/isolators (BPFIs) are based on series-cascaded non-reciprocal resonant stages, microwave resonators and multi-resonant cells. The non-reciprocal stages are shaped by an in-parallel cascaded transistor-based path and a transmission line (TL) that result in a zero-phase resonance in the forward direction and high isolation in the reversed one. This includes coupling routing diagrams (CRDs) of BPFs that result in low- and high-order transfer functions with and without transmission zeros in their forward direction and high levels of isolation in the reverse one. BPFIs provide alternative-type of filtering responses (e.g., flat-passband, quasi-elliptic) with and without gain in the forward direction and high levels of isolation in the reversed one. BPFIs include five planar microstrip/lumped element (LE) prototypes using hybrid combinations of non-reciprocal resonant stages, microwave resonators and multi-resonant cells.

Abstract: A magnetic field application device according to an embodiment includes a first coil assembly and a second coil assembly spaced apart in parallel from each other, a power supply configured to apply respective currents to the first coil assembly and the second coil assembly, a controller, and a resonator accommodation unit disposed between the first coil assembly and the second coil assembly, wherein each of the first coil assembly and the second coil includes a coil configured to generate a magnetic field, a guide member connected to a terminal of the coil, a magnetic material mount connected to a terminal of the guide member, and a magnetic material fixed to the magnetic material mount, and wherein the controller is configured to control the currents applied from the power supply to the first coil assembly and the second coil assembly.

Abstract: 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.

Abstract: A multi-mode filter with a resonator having a plurality of resonator bodies which are rectangular prisms and the filter being configured with a through hole that electrically connects an input and an output to the center of a coupling structure between a respective pair of slabs. The multi-mode filter further comprising a plurality of coupling aperture segments which are coupling structures between each pair of resonator bodies or slabs such that two triangular apertures at opposite corners of at least two different slab-cube interfaces are utilized with the triangular apertures being diagonally opposed to one another across the respective interface.

Abstract: The present invention relates to a cavity filter and a connecting structure included therein. The cavity filter includes: an RF signal connecting portion spaced apart, by a predetermined distance, from an outer member having an electrode pad provided on a surface thereof; and a terminal portion configured to electrically connect the electrode pad of the outer member and the RF signal connecting portion so as to absorb assembly tolerance existing at the predetermined distance and to prevent disconnection of the electric flow between the electrode pad and the RF signal connecting portion, wherein the terminal portion includes: a first side terminal contacted with the electrode pad; and a second side terminal having a housing space in which a part of the first side terminal is housed, and connected to the RF signal connecting portion, wherein the first side terminal is provided as an elastic deformable body whose part is radially widened or narrowed against an assembly force provided by an assembler.

Abstract: One aspect of the present disclosure relates to a power electronics device for an electrically-driven charging device for an engine, said power electronics device comprising one or more power electronics components which are designed to operate an electrically-driven charging device for an engine, first and second conductors for guiding current for the one or more power electronics components, and a choke for filtering electromagnetic interference. The choke has a magnetic core which forms a closed ring about the first and second conductors and comprises a tongue which extends, arising from the closed ring, between the first and second conductors.

Abstract: A band stop filter can include a circuit board having a first surface and an opposing second surface. The circuit board can have a transmission line on the first surface. The band stop filter can include a dielectric cavity resonator physically coupled to the second surface of the circuit board. The dielectric cavity resonator can have a coupling aperture configured to magnetically couple the dielectric cavity resonator to the transmission line, and to cause excitation of the dielectric cavity resonator in a second order transverse electric (TE) mode.

Abstract: An antenna apparatus includes an antenna integrated with a filter. The antenna apparatus includes a plurality of planar resonators where at least some of the resonators are each enclosed in a metal cavity and at least one planar resonator is exposed to free space to form a radiator element. The antenna apparatus has a filter transfer function that is at least partially determined by dimensions of the planar radiator element and the position of the planar radiator element within the antenna apparatus.

Abstract: The present disclosure is generally directed to utilizing capacitors stacks with capacitors mounted in a terminal-to-terminal mounting orientation to reduce overall footprint of capacitor arrays for bypass filtering circuits. In an embodiment, each capacitor stack includes at least a first capacitor, a second capacitor, and a ground plane interconnect. The first capacitor includes first and second terminals disposed opposite each other. The first terminal provides a mating surface to couple to the second capacitor, the second terminal couples to a ground plane. The second capacitor includes first and second terminals disposed opposite each other. The first terminal provides a mounting surface to electrically couple to and support the first capacitor, and the second terminal provides a mating surface to electrically and physically couple to the ground plane. Accordingly, the first capacitor can be inverted and mounted atop the second capacitor to eliminate the necessity of wire bonds, for example.

Abstract: What is disclosed is a module arrangement having an antenna layer, a shielding layer, a distribution layer and a component layer. The antenna layer supports an integrated antenna device. The shielding layer has a shielding effect relative to electromagnetic signals. The distribution layer has structures for distributing signals and/or electrical energy. Finally, the component layer supports embedded electronic components. In addition, a device comprising module arrangements and a method for manufacturing a module arrangement are disclosed.

Abstract: 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.

Abstract: A packaged radar includes laminate layers, a ground plane associated with at least one of the laminate layers, a transmit antenna and a receive antenna associated with at least one of the laminate layers, and an electromagnetic band gap structure between the transmit antenna and the receive antenna for isolating the transmit antenna and the receive antenna, the electromagnetic band gap structure including elementary cells forming adjacent columns each coupled to the ground plane, and each elementary cell including a conductive planar element and a columnar element coupled to the conductive planar element.

Abstract: A shielding apparatus which is for passively attenuating electromagnetic radiation and which comprises a plurality of cells. Each cell comprises a plurality of resonators (26) which are spaced from one another. The cells are arranged in a plurality of unit cells with each unit cell comprising a common loop (32) which surrounds at least two adjacent cells of the plurality of cells. The plurality of unit cells each have an asymmetric structure. The shielding apparatus thus has a negative refractive index for at least one selected frequency whereby electromagnetic radiation at the at least one selected frequency is passively attenuated.

Abstract: The present disclosure provides a millimeter wave LTCC filter including system ground layers and metalized vias; two first perturbation metallized vias provided in a first substrate integrated waveguide unit and two second perturbation metallized vias provided in a second substrate integrated waveguide unit; the two first perturbation metallized vias are symmetrically provided on a first diagonal of the first closed resonant cavity with respect to a geometric center of the first closed resonant cavity; the two second perturbation metallized vias are symmetrically provided on a second diagonal of the second closed resonant cavity with respect to a geometric center of the second closed resonant cavity, and the first diagonal and the second diagonal are orthogonal to each other; a first port and a second port. Compared with the related art, the millimeter wave LTCC filter of the present disclosure is small in volume, large in bandwidth, and low in loss.

Abstract: The present disclosure provides a filter comprises an enclosure having two cavities separated by a wall; a first TM dual-mode resonator and a second TM dual-mode resonator, each TM dual-mode resonator having two modes and comprising a body having a central portion with a plurality of arms extending outwardly from the central portion; a gradient aperture formed in the wall for coupling between two TM dual-mode resonators. The filter is capable of forming two transmission zeros between four resonances modes.

Abstract: A six-pole patch bandpass filter includes a dielectric substrate and six electrically-conductive isosceles-triangle patches disposed thereon. A first pair of the patches is an electrically connected pair. The first pair of patches is capacitively coupled to a first microstrip. A second pair of the patches is also an electrically connected pair. The second pair of patches is capacitively coupled to a second microstrip. A third pair of the patches are nested between and capacitively coupled to the first pair of patches and the second pair of patches.

Abstract: Apparatus comprising a first layer of electrically conductive material, a second layer of electrically conductive material, and at least one dielectric layer, which comprises a solid dielectric material, arranged between said first layer and said second layer, wherein at least one distributed resonator structure comprising a plurality of resonator posts is arranged in said at least one dielectric layer.

Abstract: This disclosure describes a dielectric filter and a communications device. In one example, the dielectric filter includes at least two dielectric resonators, a first through-hole is disposed between at least one pair of adjacent dielectric resonators, and the first through-hole is configured to cut a magnetic field between the at least one pair of adjacent dielectric resonators. In some implementations, a magnetic field distribution in the dielectric filter may be cut via the first through-hole, so that a magnetic field distribution area is reduced, and a high-order harmonic wave frequency can be increased, thereby improving a remote suppression capability and meeting the specification requirements.

Abstract: The present disclosure relates to a tunable waveguide resonator comprising a rectangular waveguide part having electrically conducting inner walls, a first waveguide port and a second waveguide port. The resonator comprises at least one tuning element positioned between the waveguide ports, where each tuning element comprises an electrically conducting body and a holding rod. The holding rod is attached to the electrically conducting body and is movable from the outside of the resonator such that the electrically conducting body can be moved between a plurality of positions within the waveguide part by means of the holding rod.

Abstract: Multiple feed, front-shielded, coplanar waveguide, direct-fed, cavity-backed slot antennas are described. Various implementations form an antenna unit capable of millimeter waveform and/or microwave waveform transmissions. An antenna comprises a conductive plate that includes an aperture. The aperture has a shape that extends along an axis that bisects the aperture into first and second bisected portions, the first bisected portion having a first geometry type, and the second portion having a second geometry type that is a bilateral symmetry shape type of the first geometry type. In implementations, the aperture is configured to radiate waveforms within a frequency range from about between 600 Megahertz (MHz) to 72 Gigahertz (GHz) by applying multiple signal feeds to the conductive plate.

Abstract: Provided is a noise filter device that is capable of suppressing electrical interference between an input-side conductive line and an output-side conductive line. A noise filter device (10) includes: a noise filter (50) connected to a distal end of an input-side conductive line (41) and a distal end of an output-side conductive line (42); and a holding member (60) that holds the input-side conductive line (41) and the output-side conductive line (42). The holding member (60) includes: a body (61) attached to a wire harness (WH) so as to surround an outer circumference thereof; and a pair of hooks (62) that are respectively formed at two ends of the body (61) in a circumferential direction thereof, and are hooked on the input-side conductive line (41) and the output-side conductive line (42) to restrict the input-side conductive line (41) and the output-side conductive line (42) from approaching each other.

Abstract: A multi-resonator filter has a signal input terminal, a signal output terminal, and a plurality of resonator components. The plurality of resonator components include an input resonator component coupled to the signal input terminal, an output resonator component coupled to the signal output terminal, and at least one intermediate resonator component coupled between the input resonator component and the output resonator component. The input resonator component, output resonator component and the at least one intermediate resonator component are arranged in a sequence to define a signal path between the signal input terminal and the signal output terminal. The at least one intermediate resonator component includes at least one multiple resonator component, where each multiple resonator component includes a pair of individual resonators coupled in parallel where each individual resonator in a given pair of individual resonators has the same resonant frequency.

Abstract: A new method, system and apparatus for mounting mechanically, thermally and electrically light emitting diode (LED), crystals, arrays or packages. The above provides an LED assembly having reduced number of components and costs, superior heat dissipation, mechanical properties and a compact structure. The use of a grid or mesh allows for more efficient and inexpensive removal of heat from one or more LEDs within an LED fixture.

Abstract: The present invention is a tunable bandpass filter to provide a constant absolute bandwidth across a tuning range, comprising of a pair of resonators to determine a filter center frequency, each said resonator has a rectangular waveguide cavity, wherein said filter center frequency depends on the dimensions of said rectangular waveguide cavity; a pair of side walls attached to said pair of resonators to form a filter housing; a tuning element movably attached to at least one of said pair of side walls and extending in said filter housing and movable orthogonally to said pair of resonators, and wherein said dimensions of said rectangular waveguide cavity change by moving said tuning element, thereby said filter center frequency is changed.

Abstract: An inductive-capacitive filter includes a first insulating-conductive strip wound around a winding axis, where the first insulating-conductive strip includes a first conductive strip joined with a first insulating strip. An inductive-capacitive filter assembly includes a first and a second insulating-conductive strip concentrically wound around a winding axis, the first insulating-conductive strip including a first conductive strip joined with a first insulating strip, and the second insulating-conductive strip including a second conductive strip joined with a second insulating strip.

Abstract: This application provides a dielectric resonator, including a dielectric body disposed in a hollow conductive housing, where the dielectric body includes a first end face and a second end face that are disposed opposite to each other and a circumferential surface connected between the first end face and the second end face. The first end face is provided with a first groove, the second end face is provided with a second groove, the first end face and the second end face are in contact with an inner wall of the conductive housing, and extension directions of the first groove and the second groove are different. This application further provides a filter. This application can implement single-sided installation of the dielectric resonator, so that an objective of miniaturization is achieved and assembly becomes easy. In addition, coupling between resonance modes can be enhanced because the extension directions of the first groove and the second groove are different.

Abstract: An object of the present invention is to prevent or reduce an error between a center frequency and a target center frequency in a coupled resonator band-pass filter which uses a post-wall waveguide. A band-pass filter (1) includes: a substrate (2) made of a dielectric substrate and sandwiched by a pair of conductor layers (3 and 4); and a post wall (11, 12) constituted by a plurality of conductor posts (11i, 12i) which pass through the substrate (2) and short-circuit the pair of conductor layers (3 and 4), the pair of conductor layers (3 and 4) and the post wall (11, 12) constituting a plurality of resonators (22 to 24) which are coupled, the pair of conductor layers serving as a pair of wide walls of the plurality of resonators, the post wall serving as a narrow wall of the plurality of resonator.

Abstract: A dielectric filter includes a plurality of resonators, wherein each resonator included in the plurality of resonators includes a tuning hole; and at least one stepped hole for adjusting capacitive coupling, wherein the at least one stepped hole is disposed between two adjacent resonators included in the plurality of the resonators, wherein the stepped hole comprises a large hole and a small through hole at a bottom center of the large hole, wherein a first sidewall and a first annular bottom of the large hole are configured with a metal conductive layer, and wherein at least one of a second sidewall of the small through hole and a second annular portion outside a bottom of the small through hole is not covered with the conductive layer.

Abstract: Example dielectric filters, transceiver devices, and base stations are described. One example dielectric filter includes a dielectric block whose surface is covered with a metal layer. The dielectric block includes at least two resonant cavities, and is provided with a via hole. The via hole is located between two adjacent resonant cavities, and an inner wall of the via hole is covered with a metal layer. A first partition ring is disposed on the surface of the dielectric block and is surrounding at least one opening of the via hole. The dielectric block is exposed in an area enclosed by an inner edge of the first partition ring and an outer edge of the first partition ring.

Abstract: An antenna including a dielectric block with a groove, and a conductor arranged in the groove. The antenna is arranged to be excited to operate as a dielectric resonator antenna and a Fabry-Perot resonator antenna.

Abstract: A cavity-type radio frequency filter is disclosed. the radio frequency filter having a cavity structure including an enclosure, a resonant element, a cover, a frequency tuning screw, and a resilient fixing member. The enclosure has a hollow inside and an open surface on one side to have a cavity. The resonant element is positioned in the hollow of the enclosure. The cover has a screw hole having a preset diameter at a position corresponding to the resonant element, and is configured to seal the open surface of the enclosure. The frequency tuning screw is configured to be screwed into the screw hole of the cover, and it has an upper end formed at least partially with a latching abutment that protrudes outwardly.

Abstract: A filter circuit may include a transmission line, a quarter wave resonator, and an electrical component coupled in series with the quarter wave resonator at a first end and to the transmission line at a second end. The electrical component may be have a frequency dependent impedance. The electrical component may be an inductor, a capacitor, or an inductor in series with a capacitor. In another aspect, a filter circuit may include a transmission line, a first quarter wave resonator coupled to a first electrical component and a second quarter wave resonator coupled to a second electrical component. Each of the first and second electrical components may be coupled to the transmission line in parallel with each other. The first and the second electrical components may have a frequency dependent impedance. The first electrical component may be the same as or different from the second electrical component.

Abstract: An antenna assembly and an antenna device including the same are provided. The antenna assembly includes antenna elements, a first printed circuit board (PCB), cavity filters, and a second PCB. The first PCB has one surface provided with the antenna elements. The cavity filters are installed on the other surface of the first PCB and electrically connected to the plurality of antenna elements. The second PCB has one surface electrically connected to the cavity filters and includes at least a power amplifier, digital processing circuit, and calibration network. The second PCB includes one or more first processing areas and one or more second processing areas extending in parallel with each other. The digital processing circuit is disposed in the second processing area and not in the first processing area. The power amplifier is disposed in the first processing area and not in the second processing area.

Abstract: A compact wideband RF antenna for incorporating into a planar substrate, such as a PCB, having at least one cavity with a radiating slot, and at least one transmission line resonator disposed within a cavity and coupled thereto. Additional embodiments provide stacked slot-coupled cavities and multiple coupled transmission-line resonators placed within a cavity. Applications to ultra-wideband systems and to millimeter-wave systems, as well as to dual and circular polarization antennas are disclosed. Further applications include configurations for an antenna based on a monopole element and having a radiation pattern that is approximately isotropic.

Abstract: Reconfigurable non-reciprocal integrated-optics-based devices are disclosed. The non-reciprocal devices include: a phase-sensitive device, such as a microring waveguide; a magneto-optic layer; and an electromagnet. These elements are operatively coupled such that a magnetic field generated by current flow through the electromagnet gives rise to a non-reciprocal phase shift in the phase-sensitive device. The non-reciprocal phase shift leads to a difference in the way that a light signal travels in the forward and backward directions through one or more bus waveguides that are operatively coupled with the phase-sensitive element. The non-reciprocity is reversible by reversing the direction of drive current flow in the electromagnet, which enables the inter-port connectivity of the ports of these bus waveguides to be reconfigured based on the direction of the drive current flow. Examples of reconfigurable isolator and circulator embodiments are described.

Abstract: A dielectric resonator, a dielectric filter using the dielectric resonator, a transceiver, and a base station. The dielectric filter includes a body made of a solid-state dielectric material, where a plurality of indentations are disposed at a first surface of the body and where at least one of a hole or a groove is disposed between adjacent indentations of the plurality of indentations, and a conducting layer, wherein the first surface and other surfaces of the body, surfaces of the plurality of the indentations, and an interior of the at least one of the hole or the groove are covered with the conducting layer.