Abstract: Multi-pair differential lines printed circuit board common mode filters are generally described. In one embodiment, the apparatus includes a multi-layer printed circuit board, a first signal line and a second signal line forming a first differential pair on a first layer of the printed circuit board, a second differential pair on the first layer of the printed circuit board, and a common mode filter on a second layer of the printed circuit board, the common mode filter comprising an absence of a predominantly occurring dielectric material of the printed circuit board, the common mode filter spanning an area directly below at least a portion of both the first and the second differential pairs. Other embodiments are also described and claimed.

Abstract: There is provided an improved filter having resonators substantially disposed between conductive planes which form one or more loading capacitors that are in turn coupled to the resonators. Further, inclusion of a designed void or slot in one or more of the conductive planes allows for control of an introduced transmission zero to manipulate the performance of the filter to achieve desired results, such as improved skirt performance.

Abstract: An apparatus includes a filter that includes a multi-layer planar structure having a first layer and a second layer. The first layer includes an electronic band-gap structure that is configured to suppress a first frequency component of signals passing through the filter. The second layer includes a quarter-wavelength stub that is configured to suppress a second frequency component of the signals passing through the filter.

Abstract: In a filter structure for suppressing a spurious signal, a conductor layer in a printed circuit board includes a pattern with interconnected pattern elements (106 to 114). A pattern element includes a low-impedance conductive region (119) the capacitance of which against a second conductor layer of the printed circuit board is dominant over the inductance. A pattern element includes at least two adjacent high-impedance conductor strips (115, 116) in a first direction, connected to a low-impedance conductive region, and at least two adjacent high-impedance conductor strips (117, 118) in a second direction, connected to the low-impedance conductive region. The inductance of each high-impedance conductor strips is dominant over the capacitance against the second conductor layer. The high-impedance conductor strips form together with the low-impedance conductive region a plurality of resonance points in the frequency range, thus achieving sufficient stop-band width.

Abstract: In an ultra-wideband (UWB) band-pass filter, an equivalent circuit of a band-pass filter for direct frequency conversion is configured to have a series LC resonator and a parallel LC resonator, the parallel LC resonator is implemented as a short stub and an open stub, and the series LC resonator is implemented by modeling an inductor and a capacitor as a distributed constant circuit. The series LC resonator is implemented to have a 3D structure for effective designing of the band-pass filter by a new method of implementing a series resonator circuit. In the UWB band-pass filter, a low-pass filter for improving band-stop characteristics is additionally connected.

Abstract: A unit of a metamaterial includes an uppermost part electrode, a lowermost part electrode, a first internal electrode, a second internal electrode, a third internal electrode, a fourth internal electrode, and a transmission line. The transmission line connects a section of the uppermost part electrode which extends in the ?z direction to a section of the lowermost part electrode which extends in the +z direction. The length of the transmission line is set to substantially ½ of a resonant wavelength. The first internal electrode and the fourth internal electrode are respectively placed so as to be opposed to the uppermost part electrode and the lowermost part electrode. The first internal electrode and the fourth internal electrode are not electrically connected directly to each other.

Abstract: An electronic component includes a laminated body including a plurality of insulator layers laminated on each other in a lamination direction. A first strip line resonator is provided within a first region in the laminated body. A second strip line resonator is provided within a second region in the laminated body. A third strip line resonator is provided within the first region in the laminated body, and in a planar view in a lamination direction, the third strip line resonator and the first strip line resonator sandwich therebetween the second strip line resonator. A coupling conductor capacitively couples the first strip line resonator and the third strip line resonator.

Abstract: A broadband coupling filter for generating a notch filtering effect is disclosed. In the broadband coupling filter, a substrate includes a first layer, a second layer and a third layer. A first signal terminal, a second signal terminal, and a block transmission line are formed in the first layer, wherein the first signal terminal is used for receiving a signal, and the second signal terminal is used for outputting a filtering result of the signal. A grounding plate is formed in the second layer, having a hole. A third signal terminal, a forth signal terminal and a second block transmission line are formed in the third layer. A connection unit is further formed in the third layer, for connecting the third signal terminal and the forth signal terminal.

Abstract: A bandpass filter for a wide frequency band such as UWB is disclosed. The bandpass filter can receive a pair of signals, namely a differential signal, and output a single signal, namely an unbalanced signal. A transmission characteristic of the bandpass filter having an attenuation pole near both sides of the passband can be achieved.

Abstract: A bandpass filter for a wide frequency band such as UWB is disclosed. The bandpass filter can receive a pair of signals, namely a balanced signal, and output a pair of signals. The bandpass filter comprises a plurality of ½ wavelength resonance electrodes, a plurality of ¼ wavelength resonance electrodes and a plurality of coupling electrodes. A transmission characteristic of the bandpass filter having flat and low loss over the entire region of the broad pass band can be achieved.

Abstract: A device according to various aspects of the present invention generally includes a surface mount device having a top side, a bottom side, a plurality of sidewalls, and a circuit comprising one or more layers. The device includes a first conductive surface covering a portion of one of the sidewalls for providing an input to the circuit, a second conductive surface covering a portion of one of the sidewalls for providing an output from the circuit, and a third conductive surface covering a portion of one of the sidewalls for providing an electrical ground to the circuit. When the surface mount device is mounted to a provided mounting surface, at least one layer of the circuit is orthogonal to the provided mounting surface.

Abstract: A laminated balance filter includes a first capacitor electrode and a ground electrode that are disposed opposite to each other to define a capacitor at an unbalanced side. An unbalanced side coil is provided in a dielectric layer. Three balanced side coils are provided in three dielectric layers. The three balanced side coils preferably have a substantially helical shape and are wound in the same winding directions. The coil located in the center of the three balanced side coils is disposed near the unbalanced side coil so as to be electromagnetic-field-coupled to the unbalanced side coil.

Abstract: A compact Ku band microwave diplexer configured as a three port surface mount component on a miniature alumina substrate. Input signals occurring at a common port having frequencies within a first pass band are passed to a second port while being isolated from signals occurring at a third port. Signals occurring at the third port are passed to the common port while being isolated from the signals at the second port. A microstrip dual spur line filter is used combined with open circuit stubs to provide enhanced second harmonic suppression on the transmit side, while using a coupled line microstrip filter on the receive side. This approach allows for compact size and automated component assembly through pick and place and reflow manufacturing techniques.

Abstract: A band pass filter is provided. The band pass filter includes a first resonator which includes a first pattern and first microstrip line; a second resonator which includes a second pattern and second microstrip line; a third pattern vertically arranged between the first pattern and second pattern; and a ground pattern connected with the third pattern, embodying a band pass filter using a resonator having a length of 1/16 wavelength or less, instead of a resonator having a length of ¼ wavelength.

Abstract: An electromagnetic resonance coupler includes a transmission resonator provided on the transmission substrate and having a shape obtained by opening a loop shape including an inwardly recessed portion in part to make a transmission resonator slit, transmission wiring connected to the transmission resonator, a reception substrate, a reception resonator provided on the reception substrate and having the same size and shape as the transmission resonator, and reception wiring connected to the reception resonator. The transmission and reception resonators are symmetric with respect to a point and face each other so that their contours match. In the transmission resonator, at least part of wiring constituting the recessed portion is close to wiring other than the at least part of wiring at a distance less than or equal to four times the wiring width of the transmission resonator.

Abstract: A method for forming a semiconductor structure includes forming an isolation region in a semiconductor substrate; forming a conductive layer over the isolation region; forming a first dielectric layer over the conductive layer; forming a plurality of conductive vias extending through the first dielectric layer to the conductive layer and electrically contacting the conductive layer; forming a second dielectric layer over the first dielectric layer; and forming a conductive ground plane in the second dielectric layer. Each of the plurality of conductive vias is in electrical contact with the conductive ground plane, and the conductive ground plane includes an opening, wherein the opening is located directly over the conductive layer. At least one interconnect layer may be formed over the second dielectric layer and may include a transmission line which transmits a signal having a frequency of at least 30 gigahertz.

Abstract: A microwave circuit (1) in strip line technology contains metallic resonator strips (21,22,23,24,25,26,27,28,29) on one side of a dielectric layer. Alternately another end of consecutive resonator strips (21,22,23,24,25,26,27,28,29) is connected by means of at least one via (61,62,63,64,65,66,67,68,69; 61?,62?,63?,64?,65?,66?,67?,68?,69?; 6) to a metallic surface on an opposite side of said dielectric layer. Said end of each resonator strip (21,22,23,24,25,26, 27,28,29) is connected to at least one via (61,62,63,64,65,66,67,68,69,61?,62?,63?,64?,65?,66?,67?,68?,69) and is formed relative to said at least one via (61,62,63,64,65,66,67,68,69,61?,62?,63?,64?,65?,66?,67?,68?,69?; 6,6?; 6?, 6??; 6??) so that the effective electrical length of each resonator strip (21,22,23,24,25,26,27,28,29) connected through the via (61,62,63,64,65,66,67,68,69,61?, 62?,63?,64?,65?, 66?,67?,68?,69?) is identical.

Abstract: One embodiment of a high-frequency filter includes a band-rejection filter including a plurality of reflection-type resonance elements and a filter circuit element provided between the reflection-type resonance elements, wherein an electrical length between the reflection-type resonance elements between which the filter circuit element is provided is an odd multiple of 90 degrees in a rejection band of the band-rejection filter.

Abstract: A signal transmission apparatus includes two circuit layers. First and second ground sheets each has a rectangular area are arranged in the two circuit layers respectively. A third ground sheet is arranged between the two circuit layers. A differential pair includes a transmission line arranged between the first and third ground sheets and a transmission line arranged between the second and third ground sheets. The first to third ground sheets have same electric potential. Projections of the two rectangular areas on a surface where the third ground sheet in only have one common border with the third ground sheet. The third ground sheet is formed by extending the common border along a signal transmission direction. The differential pair includes a number of section pairs each composed of two sections arranged in the two transmission lines symmetrically. Every two adjacent section pairs are equivalent to a capacitor and an inductor.

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: A filter of the present invention includes a plurality of via structures with a multilayer substrate. Each of the plurality of via structures includes first, second and third functional sections. One end of a signal via of the first functional section is connected to one end of a signal via of the second functional section and another end of the signal via of the second functional section is connected to two signal vias of the third functional section. Those signal vias are surrounded by a plurality of ground vias. Input and output ports of the filter are connected to another end of the signal via of each first functional section.

Abstract: Metallization layer structures for reduced changes in radio frequency characteristics due to registration error and associated methods are provided herein. An example resonator includes a first conductive layer defining an error limiting feature and a second conductive layer. The resonator further includes at least one communication feature configured to electrically couple the first conductive layer and the second conductive layer at a communication position. The error limiting feature is configured to reduce changes in radio frequency characteristics of the resonator due to registration error. Methods of manufacturing resonators are also provided herein.

Abstract: A dual-band bandpass filter according to the present invention includes a plurality of dual-band bandpass resonators. The dual-band bandpass resonator includes a central conductor having a central axis aligned with an input/output direction, a pair of grounding conductors, a central conductor short-circuit part and a pair of stub conductors that are formed on a surface of a dielectric substrate. The pair of grounding conductors are disposed on the opposite sides of the central conductor with a space interposed therebetween. The central conductor short-circuit part short-circuits the pair of grounding conductors, and one end of the central conductor is connected to the central conductor short-circuit part.

Abstract: Disclosed are a resonator configured by a microstrip line and a filter. A ring resonator in accordance with an embodiment of the present invention includes a ring resonant unit configured by a microstrip line; and a via connecting the resonant unit with a ground surface. In accordance with the embodiment of the present invention, the ring resonator configured by a microstrip line including a via and a filter, thereby providing a smaller and cheaper resonator and filter.

Abstract: A resonance element according to an embodiment transmits a radio-frequency signal, and includes a first substrate, a second substrate, a first circuit element formed on the first substrate, a second circuit element formed on the second substrate, and a transmission line connecting the first circuit element and the second circuit element, and a peak of even mode resonance in which the first circuit element and the second circuit element resonate in the coordinated phase is within a bandwidth of a transmission signal, and a peak of odd mode resonance in which the first circuit element and the second circuit element resonate in a reverse phase is outside the bandwidth.

Abstract: A filter of an embodiment includes: a microstrip-line planar filter that includes an input line, resonators, and an output line, and has a passband with a center frequency f0; a metal case housing the planar filter; and structural components that include dielectric components, the structural components arranged in the metal case at an interval in the traveling direction of electromagnetic waves from the input line to the output line or in a direction perpendicular to the wavefront of the standing waves generated by the electromagnetic waves resonating in the metal case, the interval being ? to ½ wavelength in terms of the electrical length of the center frequency f0.

Abstract: An LR polyphase filter implemented with inductors and resistors and capable of operating at high frequencies is described. In one design, the LR polyphase filter includes first and second paths, with each path including an inductor coupled to a resistor. The first and second paths receive a first input signal and provide first and second output signals, respectively, which may be in quadrature. For a differential design, the polyphase filter further includes third and fourth paths, which receive a second input signal and provide third and fourth output signals, respectively. The four output signals may be 90° out of phase. The first and second input signals are for a differential input signal. The first and third output signals are for a first differential output signal, and the second and fourth output signals are for a second differential output signal. Each inductor may be implemented with a transmission line.

Abstract: An exemplary embodiment of the present disclosure illustrates a multilayer circuit board structure, for suppressing the undesired electromagnetic wave propagation within a specific frequency band. The multilayer circuit board structure includes a plurality of crystals and a plurality of conducting channels, wherein a crystal includes a first through fourth conducting planes, at least a first conducting connector, and at least a second conducting connector, wherein the first through the fourth conducting planes are substantially parallel to each other. The first conducting plane is electrically connected to the third conducting plane through the first conducting connector. The fourth conducting plane is electrically connected to the second conducting plane through the second conducting connector. The first and the third conducting planes are configured to be electrically separated from the second and the fourth conducting planes.

Abstract: A printed filtering antenna is provided. This filtering antenna comprises an antenna part and a coupled line resonator. The antenna part is directly connected to a coupled line resonator and occupies an antenna area. The coupled line resonator provides a filtering mechanism together with the antenna part. The coupled line resonator comprises a short-circuited stub and an open-circuited stub. The short-circuited stub comprises an open-circuited end and a short-circuited end connected to ground. The open-circuited stub is parallel to the short-circuited stub. The open-circuited stub comprises a first end o and a second end. The first end is connected to the feed point and is corresponding to the open-circuited end of the short-circuited stub such that the open-circuited stub is coupled to the short-circuited stub.

Abstract: In one exemplary embodiment, a transmission line geometry or structure may readily be realized as periodic printed coupled/uncoupled microstrip lines on dielectric and/or suitable biased ferromagnetic substrates. An example of a transmission line geometry or structure may be adapted to emulate extraordinary propagation modes within bulk periodic assemblies of anisotropic dielectric and magnetic materials. For instance, wave propagation in anisotropic media may be emulated by using a pair of coupled transmission lines (30, 32) having a specially designed geometry, thereby enabling mold wave dispersion in a microwave or optical guided wave structure. Degenerate band edge resonances, frozen modes, other extraordinary modes, and other unique electromagnetic properties such as negative refraction index may be realized using unique geometrical arrangements that may, for example, be easily manufactured using contemporary RF or photonics/solid state technology.

Abstract: In an exemplary embodiment, a spurline filter comprises a capacitive element connected to a spur and either a through-line of the spurline filter or ground. In another embodiment, multiple capacitive elements are connected to the spur. In an exemplary embodiment, the capacitively loaded spurline filter provides a band rejection frequency response similar to the band rejection frequency response of a similar spurline filter that does not comprise at least one capacitive element but the capacitively loaded spurline filter has half the layout area or less. In an exemplary embodiment, the spurline filter comprises capacitive elements, where the capacitive elements are configured to reduce the resonant frequency of the filter.

Abstract: A bandpass filter includes three resonators of which adjacent two are electromagnetically coupled to each other, and two coupling paths connected in parallel for forming capacitive coupling between non-adjacent two of the resonators. Each of the two coupling paths includes at least one capacitor and an inductor connected in series. The two coupling paths function to form an attenuation pole at a frequency lower than the passband frequencies in the pass attenuation characteristics of the bandpass filter.

Abstract: An electromagnetic band gap (EGB) structure includes a substrate made of an isolating material. A plurality of identical planar transmission line segments are formed one under another in conductor layers embedded in the substrate. Vertical transitions connect one by one the plurality of planar transmission line segments. Adjacent ones of the vertical transitions are equally spaced on a predetermined distance in a direction parallel to the transmission line segments, thereby the vertical transitions serve as periodical inclusions forming the EBG structure.

Abstract: A transmission line with a structure which is capable of forming a passive equalizer and an electrical apparatus using the same are illustrated. The transmission line has a substrate, a ground plane, a defect ground structure, a pair of transmission conducting lines, and at least one stub. The substrate has a plurality of surfaces. The ground plane is located on at least one of the surfaces. The defect ground structure is formed on the ground plane. The pair of transmission conducting lines is located on one of the surfaces, and stretching over the defect ground structure. The at least one stub is located above a plane of the defect ground structure, extending along with at least one side of two sides of the pair of the transmission conducting lines, and electrically coupled to the pair of the transmission conducting lines and the ground plane.

Abstract: An electromagnetic bandgap structure and a printed circuit board that can solve a mixed signal problem between an analog circuit and a digital circuit are disclosed. In accordance with an embodiment of the present invention, an electromagnetic bandgap structure is stacked with a first metal layer, a first dielectric layer, a metal plate, a second dielectric layer and a second metal layer, and an odd number of vias can be serially connected through a metal line between the first metal layer and the metal plate. This electromagnetic bandgap structure can have a small size and a low bandgap frequency.

Abstract: A stripline filter that suppresses a fundamental wave frequency without increasing the size of a board and in which a harmonic frequency is easily set to a desired frequency. The stripline filter includes a glass layer having a relative dielectric constant lower than that of a dielectric board. A first top surface line is provided on a top surface of the dielectric board and has a resonant open end. A second top surface line and a side surface electrode are provided on the glass layer so as to extend from positions connected to the first top surface line.

Abstract: There is described a duplexer comprising: a dielectric substrate having a circuit-receiving surface and an opposite surface; a ground structure deposited on the circuit-receiving surface or the opposite surface; a first filter connectable to a first terminal and having a first frequency bandpass; a second filter connectable to a second terminal and having a second frequency bandpass different from the first frequency bandpass, the first filter and the second filter each having at least one filter section deposited on the circuit-receiving surface; and an uncovered coupling circuit connectable to a third terminal and deposited on the circuit-receiving surface between the first filter and the second filter, the coupling circuit being spaced apart from the first and second filter by a coupling gap and configured for electromagnetically coupling the first filter and the second filter together.

Abstract: The present invention relates to a high rejection stop band filter and a diplexer using such filters. The stop band filter comprises on a substrate with a ground plane, a transmission line extending between an input and an output and comprises several resonators formed of “stubs” in printed open circuit embedded into the transmission line, the resonators being positioned in parallel together and interconnected in series in the same direction or head to tail. The filters are particularly useful in mobile devices operating in two concurrent frequency bands.

Abstract: By having stages of a single-to-balanced band pass filter, except for a stage which receives a single-terminal signal, to not be coupled to ground, noises cannot have an available path to enter the single-to-balanced band pass filter so that common-mode signals may be reduced in magnitude.

Abstract: A monolithic microwave integrated circuit structure having a semiconductor substrate structure with a plurality of active devices and a microwave transmission line having an input section, an output section and a interconnecting section electrically interconnecting the active devices on one surface and a metal layer on an opposite surface overlaying the interconnection section and absent from overlaying at least one of the input section and the output section.

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: The invention relates to a switchable band-pass filter. In particular, the invention relates to a narrowband switchable band-pass filter over a broad frequency band with two filter elements (including microstripline technology, suitable for use as a cosite filter with a compact structure, which is particularly suitable for efficient mass production and robust in operation. The two filter elements in this context are coupled to one another, on the one hand via a switchable coupling device and, on the other hand, via a direct electromagnetic interaction.

Abstract: A multilayer electronic component and a multilayer electronic component manufacturing method are capable of easily controlling the degree of magnetic field coupling between inductors. Via-hole conductors are arranged so that they extend in a lamination direction in a laminate, and function as a first inductor. Via-hole conductors are arranged so that they extend in the lamination direction in the laminate, and function as a second inductor. A first capacitor and the first inductor define a first resonance circuit. A second capacitor and the second inductor define a second resonance circuit. The via-hole conductors are arranged in a first insulating layer so that they are spaced apart from each other by a first distance. The via-hole conductors are arranged in a second insulating layer so that they are spaced apart from each other by a second distance that is different from the first distance.

Abstract: Various exemplary embodiments relate to a support assembly for a planar filter. The assembly includes a u-shaped housing with angled surfaces at the inner corners of the u-shape, a first dielectric plate having a first angled surface in contact with one of the angled surfaces of the housing, a second dielectric plate having a second angled surface in contact with the other angled surface of the housing, at least one compressible ring, and a cover. The planar filter is supported between the first dielectric plate and the second dielectric plate. The cover compresses the compressible ring to apply downward force on the first and second dielectric plates. The downward force is translated to an inward force by the angled surfaces of the housing. The angled surfaces of the housing apply an inward force on the first dielectric plate and the second dielectric plate.

Abstract: An ultra-wideband bandpass filter having two adequately-wide pass bands, and a wireless communication module and a wireless communication apparatus which employ the bandpass filter are provided. In a bandpass filter, first resonant electrodes are arranged on a first interlayer of a multilayer body in an interdigital form; a plurality of second resonant electrodes are arranged on a second interlayer in an interdigital form; and an input coupling electrode and an output coupling electrode are arranged on a third interlayer located between the first interlayer and the second interlayer. The input coupling electrode faces an input-stage first resonant electrode and an input-stage second resonant electrode in an interdigital form. The output coupling electrode faces an output stage first resonant electrode and an output-stage second resonant electrode in an interdigital form.

Abstract: A resonant via structure is provided with a multilayer substrate, a signal via conductor and ground vias. The multilayer substrate includes conductor layers and a dielectric. The dielectric isolates each of the conductor layers. The signal via conductor is disposed through the multilayer substrate. The ground vias are disposed through the multilayer substrate and around the signal via conductor. The dielectric comprises two sections disposed between the signal via and ground vias, in the plane of conductor layers. The first section is disposed between the first layer and other layer of the conductor layers. The second section is disposed between the other layer and the last layer of the conductor layers.

Abstract: A coupled line filter includes: a first line resonator connected input port and a second line resonator connected with output port each having an electrical length of 270° at a predetermined center frequency, the first and second line resonators being disposed parallel to each other; and a third line resonator including one or more line resonators disposed between the first line resonator and the second line resonator, each line resonator having an electrical length of 90° at the center frequency and a first side aligned with first sides of the first line resonator and the second line resonator, wherein an order of the coupled line filter is determined by summing the number of the line resonators included in the third line resonator and the first and second line resonators.

Abstract: A spin wave device according to an embodiment includes: an input interconnect transmitting an input impulse signal; a multilayer film including a foundation layer; a first magnetic layer formed on the multilayer film and generating spin waves when receiving the input impulse signal, the spin waves propagating through the first magnetic layer; a plurality of input electrodes arranged in a straight line on the first magnetic layer, being connected to the input interconnect, and transmitting the input impulse signal to the first magnetic layer; and a plurality of sensing electrodes sensing the spin waves, being arranged on the first magnetic layer, and being located at different distances from one another from the straight line having the input electrodes arranged therein, and the following equation is satisfied: d=Vg×t0.

Abstract: This coplanar differential bi-strip delay line includes two conducting strips disposed on one and the same face of a dielectric substrate and each comprising a first and a second end. The two first ends of the two conducting strips are respectively joined to two conductors of a first bi-strip port for connection to a first external differential device. The two second ends of the two conducting strips are respectively joined to two conductors of a second bi-strip port for connection to a second external differential device.

Abstract: A filter for filtering noise generated by a differential signal having a specific wavelength transmitted by a first transmission line and a second transmission line is disclosed. The filter includes a multi-layer substrate, a first microstrip line and a second microstrip line. The first and the second transmission lines and the first and the second microstrip lines are disposed at the multi-layer substrate. In addition, one end of the first microstrip line and one end of the second microstrip line are electrically connected to the first and the second transmission lines, respectively, by passing through the vias, and the other end is in a floating state. The impedances of the first and the second microstrip lines match the impedances of the first and the second transmission lines, respectively. Thus, the first and the second microstrip lines may filter the noise generated by the differential signal having the specific wavelength.