Abstract: Pins on an RFIC package carry RF signals between the package and a PCB. A first capacitor is coupled between a selected pin of the RFIC package near the pins carrying the RF signals and a radio-frequency ground on the PCB. A coupling between the RFIC package and the PCB is modeled, and includes modeling of the pins of interest and at least one parasitic element of the coupling. A capacitance of the first capacitor is selected based on the modeling to obtain desired performance at selected operational frequencies. A second capacitor may be coupled between the selected pin a radio frequency ground of the RFIC package. An inductor may be coupled in parallel across the first capacitor.

Abstract: A defected ground structure with shielding effect is provided. The structure includes a dielectric layer, a defected metal layer, a grounded metal layer and at least a conductive mushroom-like structure. The defected metal layer has a line-shaped opening and is disposed in the dielectric layer. The conductive mushroom-like structure is disposed between the defected metal layer and the grounded metal layer and is arranged along an extending direction of the line-shaped opening periodically. The conductive mushroom-like structure includes a laterally extending member and a vertically extending member. The laterally extending member is parallel to the defected metal layer and a distance is maintained away from the defected metal layer. The projection area of the laterally extending member on the defected metal layer covers a length of the line-shaped opening corresponding to the laterally extending member. The vertically extending member connects the laterally extending member and the grounded metal layer.

Abstract: Systems and methods for damping cable common-mode energy in magnetic environments are provided. One system includes a damping arrangement having a transmission line within an electric (E) field environment and an energy damping device formed having a conductive plastic body and positioned adjacent a conductor of the transmission line. The energy damping device is configured to dampen common-mode energy induced within the transmission line by the E field environment.

Abstract: An electromagnetic noise suppression circuit is provided. The suppression circuit comprises a first substrate, a first grounding plane and at least one transmission line. The transmission line is configured on a top surface of the first substrate and the first grounding plane is configured on the bottom surface of the first substrate. The first grounding plane comprises a first distributed coupling structure. The first distributed coupling structure and the transmission line can be equivalent to an inductor-capacitor resonant circuit. The electromagnetic noise within a designated frequency band can be suppressed by the distributed coupling structure of the electromagnetic noise suppression circuit to avoid interfering the signal transmitted by the transmission line and the electromagnetic radiation induced by the electromagnetic noise.

Abstract: An arrangement for reducing interference between circuit blocks having differences in the amount of input power and phase differences includes isolation wires located between the circuit blocks and connected to a ground.

Abstract: A data transmission system comprises: a pair of transmission lines connecting a plurality of apparatuses; a bridge termination resistor connected between the transmission lines and having a resistance value matching a differential impedance of the transmission lines; a first switch connecting the bridge termination resistor to the transmission lines when being turned on, and disconnecting the bridge termination resistor from the transmission lines when being turned off; pull-up/down resistors connected between the transmission lines and a fixed voltage node, and having resistance values respectively matching characteristic impedances of the transmission lines, the fixed voltage node being a power supply or a ground; and second switches connecting the pull-up/down resistors between the transmission lines and the fixed voltage node when being turned on, and disconnecting the pull-up/down resistors from the transmission lines when being turned off.

Abstract: A method for reducing EM radiation comprises at least one first resonance line disposed on one of electric surfaces, which is disposed at a side of a transmission line structure on one of the electric surface. The resonance line crosses over a slot of another electric surface. The slot is etched on a corresponding electric surface. In addition, the transmission line structure crosses over the slot of the electric surface. Then, the first resonance line connects the electric surface having the slot with another electric surface. It can adjust at least one of a length, a width and a shape of the first resonance line, to make an input impedance seen from a crossed point between the transmission line structure and the slot approximately 0.

Abstract: An electronic device comprising a laminate constituted by pluralities of insulation layers on which conductor patterns are formed; ground electrodes being formed on an upper-surface-side insulation layer and a bottom-surface-side insulation layer in the laminate; the laminate being partitioned to first and second regions by a first shield constituted by a line of via-holes electrically connecting the upper-surface-side ground electrode to the bottom-surface-side ground electrode; conductor patterns constituting a first filter for a first frequency band and conductor patterns constituting a first balun for the first frequency band being arranged in the first and second regions, respectively; pluralities of terminal electrodes being formed on bottom or side surfaces of the laminate; one of terminal electrodes of the first filter, which acts as an unbalanced port, being adjacent to a terminal electrode of the first balun, which acts as an unbalanced port, with no other terminal electrode than a ground electrode

Abstract: The average EMR emissions of an electronic device may be reduced by implementing an electrically-active modulated termination. For example, the impedance may be continuously varied at one or more termination locations between two metal substructures to cause a like variation in the amplitude of each component of the EMR. According to one approach, cyclically varying the electrical impedance with a period of less than the time interval over which the EMR is measured will result in a reduction in the average measured EMR.

Abstract: Interface systems and methods are provided. An interface system can include a first isolator (200) and a second isolator (300) coupled to a modular interface (110). The interface can include a plurality of conductors (120). The first isolator can be coupled to a first signal format compliant first input/output (I/O) device (130). The second isolator can be coupled to a second signal format compliant second I/O device (140). The first isolator can pass a first signal format compliant signal to, and suppress the reflection of at least a portion of a second signal format compliant signal from, the first I/O device. The second isolator can at least partially block a first signal format compliant signal from, and to pass a second signal format compliant signal to, the second I/O device.

Abstract: Provided is an assembly and process for isolating internal regions of an electromagnetic cavity from interfering electromagnetic radiation. The assembly includes a first portion defining a first electrically conducting broad wall and an elongated, electrically conducting isolating wall, coupled to and extending away from the first broad wall. The assembly also includes a second portion defining a second electrically conducting broad wall and an elongated, electrically conducting trough defined therein. The trough is sized to accept at least a portion of the isolating wall. The first and second portions are adapted for assembly in a facing arrangement in which the isolating wall is aligned with the trough. When assembled, a tip portion of the isolating wall extends to a uniform depth within the trough, such that the isolating wall-trough combination substantially rejects a transfer of electromagnetic energy across the isolating wall over at least a predetermined range of wavelengths.

Abstract: A radio frequency device is disclosed, which includes an isolation substrate, a ground layer, a first signal end, a second signal end, a radio frequency circuit, and an impedance unit. The isolation substrate includes a first plane and a second plane. The ground layer is disposed on the second plane of the isolation substrate for providing grounding. The first signal end is formed on the first plane of the isolation substrate. The second signal end is formed on the first plane of the isolation substrate and coupled to the ground layer. The radio frequency circuit is disposed on the first plane of the isolation substrate and coupled to the first signal end. The impedance unit is disposed on the first plane of the isolation substrate and coupled to the first signal end and the second signal end.

Abstract: A printed circuit board includes a substrate, a signal output circuit formed on the substrate for outputting a clock signal, a shield for covering the signal output circuit, a power supply wiring for connecting the signal output circuit and a power source, and a trap filter provided to the power supply wiring and provided inside the shield, for attenuating a frequency component corresponding to a frequency of clock signal. The trap filter includes a resonance circuit having one portion of the power supply wiring, an inner-layer wiring of the substrate located below the one portion of the power supply wiring, an inner-layer ground wiring of the substrate located below the inner-layer wiring, and a via hole for connecting the one portion of the power supply wiring and the inner-layer wiring.

Abstract: The disclosed electromagnetic wave transmission medium prevents electromagnetic leakage during high-power electromagnetic wave transmission. The sheet-form electromagnetic wave transmission medium is configured from a first mesh conductor used in transmission of electromagnetic waves having a first power; and a second mesh conductor used in transmission of electromagnetic waves having a second power. By using two mesh conductors, when said sheet-form electromagnetic wave transmission medium is used, the conduction density of the surface region where electromagnetic waves are extracted to be used for power supply assumes a coarser state than that of the other surface region.

Abstract: An HF feed bushing device is provided that is designed to connect an HF transmitter/receiver to an antenna via an external medium by means of a balanced two-wire line. The balanced two-wire line is at least partially encapsulated in a central part of a closed conduit including a wall isolating the balanced two-wire line from the external medium. Applications: Feeding of antennas via balanced two-wire lines.

Abstract: A method including receiving power, from a power line, at a device configured to communicate via the power line. The power from the power line is received at the device via a power cord of the device being connected, via a connector, to a power outlet from which the power of the power line is supplied. The connector is coupled to a first end of the power cord. The device is coupled to a second end of the power cord. The method further includes supplying a signal generated by the device to a choke located on the power cord. The choke is located closer to the first end of the power cord than to the second end of the power cord. The method further includes transmitting the signal from the choke to the power line for communication via the power line.

Abstract: A circuit card is provided that includes ground traces that extend from a resistor to a commoning bar, where a resultant electrical length between the resistor and the commoning bar and is configured to reduce energy carried on the ground terminals that could otherwise result in cross-talk. In an embodiment, the ground trace may be configured in a meandering manner. In another embodiment, the ground trace may be split and joined by an inductor.

Abstract: High frequency circuits for wireless, digital and microwave applications place requirements upon the impedance of their signal lines, interconnects and packaging. In designing and implementing the substrates for these signal lines it is beneficial to employ meta-materials to provide the desired impedance. Such meta-materials providing a means to provide modified permittivity and permeability for the substrate, these being different than the real permittivity and permeability of the insulator used. In an example embodiment, a substrate is configured as a meta-material. It is desirable therefore to have a means to model these meta-material aspects of the signal lines rapidly and accurately allowing the circuits, interconnects and packages to be designed and implemented without expensive and exhaustive iterative experimental characterization.

Abstract: Unwanted radiation is reduced in a high-frequency signal transmission line that includes a ground conductor provided with an opening that overlaps a signal line. A dielectric element assembly has a relative dielectric constant ?1 and has a first principal surface and a second principal surface. A signal line is provided in the dielectric element assembly. A ground conductor is provided in the dielectric element assembly and on the first principal surface side with respect to the signal line, faces the signal line, and is provided with an opening that overlaps the signal line. A high dielectric constant layer has a relative dielectric constant ?2 higher than the relative dielectric constant ?1 and is provided on the first principal surface so as to overlap the opening.

Abstract: In one example embodiment, a transmitter comprises a first component coupled to receive a signal for transmission and a second component communicatively coupled to the first component to transmit the signal over a transmission medium. The transmitter further comprises a planar transmission line formed on a substrate and disposed between the first and second components to couple the signal from the first component to the second component. The planar transmission line includes a first transmission line element formed on the substrate and configured to suppress radiation of EMI at a predetermined frequency.

Abstract: A printed circuit board and an electronic product are disclosed. In accordance with an embodiment of the present invention, the printed circuit board includes a first board, which has an electronic component mounted thereon, and a second board, which is positioned on an upper side of the first board and covers at least a portion of an upper surface of the first board and in which an EBG structure is inserted into the second board such that a noise radiating upwards from the first board is shielded. Thus, the printed circuit board can readily absorb various frequencies, be easily applied without any antenna effect and be cost-effective in manufacturing.

Abstract: The invention provides a transmission noise suppressing structure and a wiring board capable of suppressing a transmission noise transferred through a power supply line, stabilizing a power supply voltage, and reducing signal transmission line cross talk transmitted through the power supply line or a ground layer without being affected by a resistive layer. A transmission noise suppressing structure includes a power supply line and a signal transmission line arranged apart from each other on the same surface; a ground layer arranged apart from the power supply line and the signal transmission line; and a resistive layer arranged apart from the power supply line and the ground layer. The resistive layer has an area (I) which faces the power supply line and an area (II) which does not face the power supply line. The resistive layer and the signal transmission line are apart from each other.

Abstract: Disclosed herein are an electromagnetic bandgap structure and a printed circuit board having the same. The bandgap structure includes a conductive layer including a plurality of conductive plates, a first metal layer disposed under the conductive layer and including a first stitching pattern electrically connected to a first conductive plate of the plurality of conductive plates, and a second metal layer disposed under the first metal layer and including a second stitching pattern electrically connected to both the first stitching pattern and a second conductive plate of the plurality of conductive plates. The bandgap to structure includes stitching patterns formed in two layers different from the conductive layer, thus offering a stop-band having a desired bandwidth in a compact structure.

Abstract: A connector including a magnetic core and a cable. The cable includes a first conductor and a second conductor. The first conductor and the second conductor are wound around each other. The cable is wound a plurality of times through a center of and around the magnetic core. A first end of the first conductor and a first end of the second conductor are configured to connect to power line communication equipment. A second end of the first conductor and a second end of the second conductor are configured to connect to a power line.

Abstract: The present invention includes method and apparatus for a device including two capacitors separated by a gap within one package thereby the two capacitors are coupled to each other in such a way that the impedance between them are matched with respect to the other components along a transmission path.

Abstract: A transmission unit with reduced crosstalk signal includes a first conductor group having at least one first conductor surrounded by a first sheath and at least one second conductor surrounded by a second sheath. The first and the second conductor are axially arranged corresponding to one another. The first sheath has a dielectric coefficient higher than that of the second sheath, so that a difference in dielectric property exists between the first and the second conductor to enable reduction of crosstalk occurred during high-speed signal transmission over the transmission unit.

Abstract: There is provided a power conversion apparatus which allows a noise current or voltage to be suppressed at a low cost and in a small size, the noise current or voltage mixing into the power conversion apparatus by propagating through a control wiring connected to an external appliance. The power conversion apparatus includes a housing, connection terminals provided on the housing, a control-circuit unit provided inside the housing, a wiring for establishing the connection between the connection terminals and the control-circuit unit, a first noise-removing unit connected between the wiring and the ground potential of the housing, and a second noise-removing unit connected between the wiring and the ground potential of the housing, and also in parallel to the first noise-removing unit.

Abstract: A filtering device is capable of suppressing common mode noises upon transmission of a differential signal, and includes a differential transmission line, a grounding layer, a dielectric unit and a conductive structure. The differential transmission line has a pair of conductive traces spaced apart from each other. The grounding layer is spaced apart from the differential transmission line. The dielectric unit is disposed between the differential transmission line and the grounding layer. The conductive structure is embedded in the dielectric unit, is coupled electrically to the conductive traces and the grounding layer, and cooperates with the differential transmission line, the grounding layer and the dielectric unit to form a stacked structure that has an effective negative permittivity, thereby suppressing the common mode noises coupled to the conductive traces. A differential signal transmission circuit is also disclosed.

Abstract: A cylindrical electromagnetic bandgap to reduce electromagnetic interference of a cable and a coaxial cable having the same includes a conductor patch having a curved surface to be spaced apart from the surface of the cylindrical cable to an outer side by a predetermined gap distance, and a via connecting the surface of the cylindrical cable to the conductor patch.

Abstract: Disclosed herein are an electromagnetic bandgap structure and a printed circuit board having the same. The bandgap structure includes a conductive layer including a plurality of conductive plates; and a metal layer disposed over or under the conductive layer and including a stitching pattern to electrically connect a first conductive plate to a second conductive plate of the plurality of conductive plates. The bandgap structure includes a spiral stitching pattern formed in a metal layer different from the conductive layer, thus offering a stop-band having a desired bandwidth in a compact structure.

Abstract: A device to attenuate EMI between a source and a load is provided. The device includes a first cable to electrically couple the source and the load and a second cable positioned adjacent to the first cable and configured to attenuate a common-mode current.

Abstract: An electromagnetic bandgap structure includes: first conductive plates, placed on a first planar surface; second conductive plates, placed on a second planar surface; a first conductive trace, electrically connecting any two adjacent first conductive plates with each other on the first planar surface, in which the two adjacent first conductive plates are in a first direction; a second conductive trace, electrically connecting any two adjacent second conductive plates with each other on the second planar surface, in which the two adjacent second conductive plates are in the first direction; a first stitching via, electrically connecting any two adjacent conductive portions lined up in a direction different from the first direction on the first planar surface with each other; and a second stitching via, electrically connecting any two adjacent conductive portions lined up in a direction different from the first direction on the second planar surface with each other.

Abstract: A printed circuit board includes a signal layer and a ground layer adjacent to the signal layer. The signal layer includes a pair of differential transmitting lines. The ground layer includes a common mode filter formed by hollow spiral patterns in the ground layer. The common mode filter includes two filter portions respectively arranged at opposite sides of a projection of the pair of differential transmitting lines onto the ground layer. Hollowed areas of the two filter portions are bridged by a void.

Abstract: An electromagnetic bandgap structure includes: first conductive plates, placed on a first planar surface, in which the first conductive plates are lined up in a first direction; second conductive plates, placed on a second planar surface and arranged at an area corresponding to an area in which the first conductive plates are disposed, in which the second conductive plates are lined up in the first direction; a first stitching via, electrically connecting any two adjacent conductive portions with each other and in which the two adjacent conductive portions are lined up in a direction that is different from the first direction on the first planar surface; and a second stitching via, electrically connecting any two adjacent conductive portions with each other and in which the two adjacent conductive portions are lined up in a direction that is different from the first direction on the second planar surface.

Abstract: A magnetic package for a communication system is disclosed the package comprises a plurality of transformers, wherein each transformer comprises a differential transformer. Each differential transformer comprises at least 2 sets of three pins. Each transformer is coupled to a twisted pair channel and a transceiver. The magnetic package includes at least one common mode transformer coupled to at least one of the transformers, wherein the at least one common mode transformer includes at least three pins. The at least three pins for the at least one common mode transformer are in a position relative to the other pins such that the package size is minimized.

Abstract: In a vehicle network for controlling electronic devices of the type having a network driver with at least one output line connected to the network through a common mode choke. A circuit for improving the immunity of the network includes a resistor and a capacitor connected in series between the signal output line and ground. The series resistor and capacitor protect the network from communication errors.

Abstract: A cable strand for the activation of electrically actuatable injection valves of internal combustion engines having a common-rail injection system, wherein the cable strand connects an engine control device with the injection valves. Electrical cables of the cable strand are molded and/or foamed in a carrier that largely prescribes the shape of the cable strand. At least one filter is also molded and/or foamed in the cable strand and is adapted to affect the electromagnetic compatibility of the cable strand arrangement.

Abstract: A connector including a magnetic core and a cable. The cable includes a first conductor and a second conductor. The first conductor and the second conductor are wound around each other. The cable is wound a plurality of times through a center of and around the magnetic core. A first end of the first conductor and a first end of the second conductor are configured to connect to power line communication equipment. A second end of the first conductor and a second end of the second conductor are configured to connect to a power line.

Abstract: A printed circuit board (“PCB”) includes a first pattern structure, a second pattern structure, a third pattern structure, and a fourth pattern structure. The first pattern structure includes a first ground pattern. The second pattern structure includes a first line pattern overlapping the first ground pattern and a second ground pattern electrically insulated from the first line pattern. The third pattern structure includes a third ground pattern overlapping the first line pattern and a second line pattern overlapping the second ground pattern. The fourth pattern structure includes a fourth ground pattern overlapping the second line pattern. Therefore, the PCB may decrease noise.

Abstract: A printed circuit board includes a signal layer and a ground layer adjacent to the signal layer. The signal layer includes a pair of differential transmission lines. The ground layer includes a first void, a second void, a third void, and a common mode filter. The first void and the second void are respectively arranged at opposite sides of a projection of the pair of differential transmission lines on the ground layer, and are bridged with the third void. The common mode filter includes a first filter portion positioned in the first void, and a second filter portion positioned in the second void. Each of the first and second filter portions includes a number of coils arranged side by side along a direction parallel to the projection of the pair of differential transmission lines.

Abstract: Disclosed is a printed circuit board into which an electromagnetic bandgap structure for blocking a noise is inserted. The electromagnetic bandgap structure can include a first conductor and a second conductor arranged on different planar surfaces, a third conductor arranged on a same planar surface that is different from a planar surface where the second conductor is arranged, and a first stitching via unit configured to connect the first conductor to the third connector through the planar surface where the second conductor is arranged and being electrically separated from the second conductor. The first conductor can include a first plate, a second plate spaced from the first plate, and a second stitching unit configured to electrically connect the first plate to the second plate through a planar surface that is different from a planar surface where the first plate and the second plate are arranged.

Abstract: In enhancing signal quality through packages, meta-materials may be used. Meta-materials are designed to make the signal act in such a way as to make the shape of the signal behave as though the permittivity and permeability are different than the real permittivity and permeability of the insulator used. In an example embodiment, a substrate (10) is configured as a meta-material. The meta-material provides noise protection for a signal line (15) having a pre-determined length disposed on the meta-material. The substrate comprises a dielectric material (2, 4, 6) having a topside surface and an underside surface. A conductive material (30) is arranged into pre-determined shapes (35) having a collective length. Dielectric material envelops the conductive material and the conductive material is disposed at a first predetermined distance (55) from the topside surface and at a second predetermined distance from the underside surface.

Abstract: An electromagnetic noise suppression circuit is provided. The suppression circuit comprises a first substrate, a first grounding plane and at least one transmission line. The transmission line is configured on a top surface of the first substrate and the first grounding plane is configured on the bottom surface of the first substrate. The first grounding plane comprises a first distributed coupling structure. The first distributed coupling structure and the transmission line can be equivalent to an inductor-capacitor resonant circuit. The electromagnetic noise within a designated frequency band can be suppressed by the distributed coupling structure of the electromagnetic noise suppression circuit to avoid interfering the signal transmitted by the transmission line and the electromagnetic radiation induced by the electromagnetic noise.

Abstract: Several implementations disclosed herein are directed to compact-size common-mode filters that are suitable for implementation in densely populated multilayered printed circuit boards (PCBs) with numerous I/O ports—as well as integrated circuit (IC) chips and I/O connectors—to suppress EMI emissions. Certain implementation are specifically directed to filters for four differential signal lines that carry 10-Gb/s digital signals. These implementations provide common-mode suppression within gigahertz frequencies where common-mode noise comprising 10-Gb/s signal is problematic, but without any significant degradation of differential-mode signals. Moreover, certain of these implementations are directed to compact-size filters that suppress common-mode signal noise at 10.3 GHz associated with the fundamental harmonic 10 Gb/s-signals of XFI and SFI. In other implementations, a combination of filters is presented to provide common-mode noise suppression at both the first harmonic frequency of 10.

Abstract: An EMI noise reduction board using an electromagnetic bandgap structure is disclosed. In the EMI noise reduction board according to an embodiment of the present invention, an electromagnetic bandgap structure having band stop frequency properties can be inserted into an inner portion of the board so as to shield an EMI noise, in which the portion corresponds to an edge of the board and in which the EMI noise is conducted from the inside to the edge of the board and radiates to the outside of the board.

Abstract: A method for reducing EM radiation comprises at least one first resonance line disposed on one of electric surfaces, which is disposed at a side of a transmission line structure on one of the electric surface. The resonance line crosses over a slot of another electric surface. The slot is etched on a corresponding electric surface. In addition, the transmission line structure crosses over the slot of the electric surface. Then, the first resonance line connects the electric surface having the slot with another electric surface. It can adjust at least one of a length, a width and a shape of the first resonance line, to make an input impedance seen from a crossed point between the transmission line structure and the slot approximately 0.

Abstract: An output filter includes a polyphase common-mode filter having a polyphase common-mode choke connected to an output of a power converter at one end, a first polyphase capacitor connected to the other end of the polyphase common-mode choke at one end, and a neutral-point detecting transformer connected to the other end of the first polyphase capacitor at one end; a capacitor/resistor series-connected body connected to a frame ground of the power converter at one end and connected to the other end of the neutral-point detecting transformer at the other end; and a polyphase normal-mode filter having a polyphase normal-mode choke connected to the other end of the polyphase common-mode choke at one end, and a second polyphase capacitor connected to the other end of the polyphase normal-mode choke at one end and having the other ends connected together and further connected to the one end of the capacitor/resistor series-connected body.

Abstract: Disclosed is a printed circuit board including an electromagnetic bandgap structure. The electromagnetic bandgap structure, which includes a first dielectric material for interlayer insulation and is for blocking a noise, is inserted into the printed circuit board. The electromagnetic bandgap structure can include a first conductive plate, a second conductive plate arranged on a planar surface that is different from that of the first conductive plate, a third conductive plate arranged on a same planar surface as the first conductive plate, and a stitching via unit configured to connect the first conductive plate and the third conductive plate through the planar surface on which the second conductive plate is arranged. A second dielectric material having a permittivity that is different from that of the first dielectric material is interposed between any two of the first conductive plate, the second conductive plate, and the third conductive plate.

Abstract: An EMI noise reduction board is disclosed. The electromagnetic interference (EMI) noise reduction board having an electromagnetic bandgap structure for shielding a noise includes: a first area having a ground layer and a power layer; a second area placed in a side portion of the first area having an electromagnetic bandgap structure therein. The electromagnetic bandgap structure includes: a plurality of first conductive plates and a plurality of second conductive plates placed on a same planar surface along the side portion of the first area; and a stitching via configured to electrically connect the first conductive plate to the second conductive plate through a planar surface that is different from the first conductive plate and the second conductive plate.

Abstract: An electronic device includes a case, a board module, and an electrostatic discharging module. The case has a conductive area. The board module is disposed in the case and has a ground end. The electrostatic discharging module is disposed on the case. Besides, the electrostatic discharging module includes a first discharging element and a second discharging element. The first discharging element is electrically connected to the ground end, and the second discharging element is electrically connected to the conductive area. There exists a gap between the first discharging element and the second discharging element, so that leak current generated by the board module can be prevented from being transmitted to the case, and that an electrostatic charge can be transmitted from the case to the ground end.