A vacuum variable capacitor includes a pre-vacuum enclosure for reducing a pressure differential across the bellows. The vacuum force load on the drive system can thereby be reduced, allowing faster movement of the movable electrode, faster capacitance adjustment of the vacuum variable capacitor and longer lifetimes of the device.

Provided are, among other things, systems, methods and techniques for processing an audio signal to add virtual bass. In one representative embodiment, an apparatus includes: (a) an input line that inputs an original audio signal; (b) a transform module that transforms the original audio signal into a set of frequency components; (c) a bass extraction filter that extracts a bass portion of such frequency components; (d) an estimator that estimates a fundamental frequency of a bass sound within such bass portion; (e) a frequency translator that shifts the bass portion by a frequency that is an integer multiple of the fundamental frequency estimated by the estimator, thereby providing a virtual bass signal; (f) an adder having (i) inputs coupled to the original audio signal and to the virtual bass signal and (ii) an output; and (g) an audio output device coupled to the output of the adder.

A printed circuit board is disclosed, comprising a plate body, a conductive pattern disposed on the plate body, a conductive metal plate, and a metal layer. The conductive metal plate has a first terminal and a second terminal, wherein the first terminal and the second terminal are fixed to the plate body. An accommodating space is between the conductive metal plate and the plate body. The metal layer covers the conductive metal plate and the conductive pattern, and is filled into the accommodating space. Therefore, a printed circuit board which has metal blocks with enough thickness is provided. The metal blocks can provide sufficiently low resistance to increase resistance efficiency of the printed circuit.

There is provided a multilayered ceramic capacitor including: a ceramic body in which a plurality of dielectric layers are stacked; an active layer including a plurality of first and second internal electrodes formed to be alternately exposed to both end surfaces of the ceramic body, having the dielectric layer interposed therebetween, to form capacitance; an upper cover layer formed above the active layer, a lower cover layer formed below the active layer and being thicker than the upper cover layer; and first and second external electrodes formed to cover both end surfaces of the ceramic body, wherein a ratio of an area Y of a region overlapped between the first and second internal electrodes to a total area X of the active layer and the upper cover layer on a cross section of the ceramic body in length-thickness (L-T) directions is in a range of 0.5 to 0.9.

In accordance with the present disclosure, one embodiment of a fractal variable capacitor comprises a capacitor body in a microelectromechanical system (MEMS) structure, wherein the capacitor body has an upper first metal plate with a fractal shape separated by a vertical distance from a lower first metal plate with a complementary fractal shape; and a substrate above which the capacitor body is suspended.

Example embodiments relate to a method of fabricating a graphene nano-mesh by selectively growing an oxide layer on a defect site of a graphene layer and etching the oxide layer to form the graphene nano-mesh. The method includes forming a graphene layer on a catalyst layer, forming an oxide layer on a defect site of the graphene layer, forming the graphene nano-mesh including a plurality of openings by etching the oxide layer, and transferring, after removing the catalyst layer, the graphene nano-mesh onto a substrate.

A tunable capacitor includes a first electrode and a second electrode, each being formed of a conductive material. The tunable capacitor further includes a third electrode between the first electrode and the second electrode, and a dielectric material interposed between the first electrode and the third electrode, and between the second electrode and the third electrode. The third electrode is movable relative to the first electrode and the second electrode by a stepper motor, to adjust and tune a capacitance of the tunable capacitor.

A tunable capacitor includes a first electrode and a second electrode, each being formed of a conductive material. The tunable capacitor further includes a third electrode between the first electrode and the second electrode, and a dielectric material interposed between the first electrode and the third electrode, and between the second electrode and the third electrode. The third electrode is movable relative to the first electrode and the second electrode by a stepper motor, to adjust and tune a capacitance of the tunable capacitor.

A plasma ignition device 20 includes a spark plug 100, a DC power supply 210, an AC power supply 220, and a coupling section 300. The coupling section 300 includes a capacitor 320 which electrically connects the AC power supply 220 to the spark plug 100. The coupling section 300 reduces the capacitance of the capacitor 320 in the second ignition mode in which transmission of AC power is halted, as compared with that in the first ignition mode in which AC power is transmitted to the spark plug 100.

A capacitance value fast-placing vacuum capacitor includes: a housing, a first electrode group and a second electrode group. A vacuum chamber is provided in the housing. The first electrode group and the second electrode group are mutually coupled and accommodated in the vacuum chamber. An electromagnetic drive mechanism is mounted on the outer side of one end of the housing. The electromagnetic drive mechanism is capable of driving the first electrode group to shift relative to the second electrode group, the vacuum capacitor is switched between two capacitance value states. In the capacitance value rapid-switching vacuum capacitor, the electromagnetic drive mechanism is configured for rapidly adjusting and switching capacitance values of the vacuum capacitor, the capacitance value switching time of the vacuum capacitor is within one hundred milliseconds, thus meeting the requirement of an application device of the vacuum capacitor for rapid matching of an impedance matcher.