Abstract: A resonator includes: a dielectric block; first and second ground electrodes provided on or in the dielectric block, and disposed to oppose each other; a first via conductor provided in the dielectric block orthogonally to the first and second ground electrodes, and having a short-circuit end connected to the first ground electrode and an open end extending toward the second ground electrode; a second via conductor interdigitally-coupled with the first via conductor, and provided in the dielectric block orthogonally to the first and second ground electrodes, and having a short-circuit end connected to the second ground electrode and an open end extending toward the first ground electrode; a first capacitor electrode provided in the dielectric block, and connected to the first via conductor; and a second capacitor electrode provided in the dielectric block, and connected to the second via conductor.

Abstract: A high frequency filter includes: an input terminal; an output terminal; and a variable capacitance circuit provided between the input terminal and the output terminal or between a ground and one of the input terminal and the output terminal, and formed on the semiconductor substrate including a capacitor and a switch element. The switch element is connected in series with the capacitor.

Abstract: In an antenna duplexer including a high band side filter, a low band side filter, and a phase shifter in a low pass configuration inserted between the high band side filter and an antenna port and taking phase matching of both filters, a resonance inductor resonating with a capacitor on the antenna port side is provided to obtain a attenuation characteristic in an optional band in an out-of-pass band of both filters by the resonance. For instance, the maximum attenuation is held at twice of the center frequency fL of a pass band of the low band side filter. The LC resonance circuit configuration can be desirably modified into a configuration such that a resonance capacitor is provided to an inductor in a phase shifter having a high band side filter configuration.

Abstract: One or more inductors and one or more capacitors are physically disposed relative to one another in series and are electrically connected to one another in parallel to form a bandstop filter. Chip inductors and chip capacitors having spaced apart conductive terminals are physically arranged in end-to-end abutting relation to minimize electrical potential between adjacent conductive terminals. The bandstop filter may be hermetically sealed within a biocompatible container for use with an implantable lead or electrode of a medical device. The values of the inductors and the capacitors are selected such that the bandstop filter is resonant at one or more selected frequencies, such as an MRI pulsed frequency.

Abstract: There are included an LPF (3) and an HPF (4) that are connected in parallel to the output of a pre-emphasis circuit (2). There is also included a gain adjusting circuit (6) that performs a gain adjustment of low-pass filter with respect to the frequency band to be passed through the HPF (4). The low frequency components of the frequency band of baseband signals outputted from the pre-emphasis circuit (2) pass through the LPF (3), while the high frequency components pass through the HPF (4). As to the outputs from the HPF (4), the gain of especially the higher part of the frequency band components to be passed through the HPF (4) is suppressed by the gain adjusting circuit (6), whereby the amplitudes of the baseband signals can be limited only for the high frequency range without using a limiter and further the peak values of the baseband signals can be inhibited from exceeding the maximum frequency deviation.

Abstract: A tunable RF filter, comprising: an emitter follower stage (2); and a common emitter stage (4); the common emitter stage (4) providing feedback to the emitter follower stage (2). The common emitter stage (4) may comprise a first transistor (Ti) being the only transistor of the common emitter stage (4); and the emitter follower stage (2) may comprise a second transistor (T2) being the only transistor of the emitter follower stage (2). A further tunable RF filter provides improved linearity, comprising: an emitter follower stage (22); a joint common emitter and emitter follower stage (24); and a gain stage (26); a common emitter output of the joint common emitter and emitter follower stage (24) providing feedback to the emitter follower stage (22), and an emitter follower output of the joint common emitter and emitter follower stage (24) providing an input to the gain stage (26).

Abstract: The electric multiple conductor system (1) is used for the transmission of signals in differential mode, and has two signal lines (5, 6) and a shared reference line (7). Each signal line (5, 6) includes an attenuation or filter element (13, 14) with a connection branch (15, 16), which runs between a branch node (20, 21) in the respective signal line (5, 6) and the reference line (7). The attenuation or filter elements (13, 14) of the respective signal lines (5, 6) are nominally of the same size. Each connection branch (15, 16) respectively includes a serial connection of a first partial branch (17, 18) having a first reactive impedance (23, 24) and a second partial branch (19) having a second reactive impedance (25). The second partial branch (19) is a shared component of all attenuation or filter elements (13, 14). The multiple conductor system (1) achieves a very high level of common mode suppression.

Abstract: A device, e.g., a hearing aid, has an electronic circuit for wireless communication of a digital signal. The circuit has a driver driving an RLC tank. The driver has a plurality of inverters whose outputs are coupled to a node of the coil via a respective one of multiple capacitors in the tank. The circuit has a controller that selectively drives one or more of the inverters with the digital signal and connects the inputs of the other inverters to a supply voltage or ground. The tank has a further plurality of series arrangements of a further capacitor and a high-voltage switch connected between the node and ground. The controller is configured for controlling the high-voltage switches.

Abstract: Among other things, a circuit includes a first and a second electromagnetic resonator, each configured to operate in a transverse electromagnetic mode, and a coupling device configured to operate in the transverse electromagnetic mode, wherein the coupling device is connected to the first and second electromagnetic resonators and inductively couples the first and second electromagnetic resonators.

Abstract: A reactance varying device comprises a voltage-controlled variable-capacitance circuit, a biasing circuit and an impedance transformer. The biasing circuit has a virtual AC ground node, which acts as a gateway to supply a bias voltage to the variable-capacitance circuit. The impedance transformer separates the variable-capacitance circuit from the AC ground node, as well as provides an inductive element to form a reactance varying LC tank.

Abstract: The magnetic material constituting a magnetic portion is a ferrite mainly containing 31-42 mol % of NiO, 2-10 mol % of ZnO, 43-48 mol % of Fe2O3, 0.5-3 mol % of Co3O4, and 10-14 mol % of CuO. The dielectric material constituting a dielectric portion is mainly composed of xBaO.y1Nd2O3.y2Bi2O3.zTiO2 wherein 0.09?x?0.25, 0.05?y1?0.20, 0<y2?0.10 and 0.60?z?0.75. The dielectric material constituting a joint portion is a BaO—TiO2—ZnO dielectric material.

Abstract: A filter adapted to DSL loop customer service end includes filter circuit, transistor control circuit, and a capacitor connected in parallel to a line, the transistor control circuit and the capacitor respectively connected to the filter circuit; the transistor control circuit is electrically connected to the capacitor; the transistor control circuit controls on and off of telecommunication signals; whereas there is no current flows through a telephone line when the telephone set is in on-hook status, the transistor control circuit is not conducted through under on-hook status so to stop the telecommunication signals from flowing through, thus to warrant that the telecommunication signals in the talking line will not shunt to a line in hook-on status for upgrading signal quality in talking mode.

Abstract: A semiconductor device interconnecting unit for inputting/outputting a high-frequency signal having a millimeter wave band to/from a semiconductor device includes a part of a band pass filter and a remainder is provided. The part of a band pass filter is configured to pass therethrough the high-frequency signal having a millimeter wave band by using an LC resonance circuit. The part and the remainder are separated from each other by a capacitive portion, the part is provided inside the semiconductor device, and the remainder is provided outside the semiconductor device.

Abstract: A capacitor is provided with a first electrode to which a direct current voltage is applied; a dielectric layer, which is arranged on the first electrode and is composed of an oxide dielectric material; and a second electrode, which is arranged on the dielectric layer, has a first portion where at least a part in contact with the dielectric layer is composed of a conductive oxide material having oxidizing property, and has a direct current voltage lower than that applied to the first electrode applied.

Abstract: A noise filter array includes filter elements, each of which includes an LC parallel resonant circuit having a coil and a capacitor and an LC series resonant circuit having a coil and a capacitor, are arranged substantially parallel to one another in an array and integrally provided. Grounding capacitors that define the filter elements are arranged so that a common ground-side electrode faces signal-side electrodes and is connected to an inductance adjusting conductor that defines the LC series resonant circuits along with the capacitors through a via hole. The lengths of the inductance adjusting conductor from a connection location within the via hole to ground terminals are substantially equal in each of the filter elements.

Abstract: Systems and devices for providing differential input/output communication with a superconducting device are described. Each differential I/O communication is electrically filtered using a respective tubular filter structure incorporating superconducting lumped element devices and high frequency dissipation by metal powder epoxy. A plurality of such tubular filter structures is arranged in a cryogenic, multi-tiered assembly further including structural/thermalization supports and a device sample holder assembly for securing a device sample, for example a superconducting quantum processor. The interface between the cryogenic tubular filter assembly and room temperature electronics is achieved using hermetically sealed vacuum feed-through structures designed to receive flexible printed circuit board cable.

Abstract: A wireless IC device includes a wireless IC chip, a power supply circuit board upon which the wireless IC chip is mounted, and in which a power supply circuit is provided, the power supply circuit includes a resonant circuit having a predetermined resonant frequency, and a radiation pattern, which is adhered to the underside of the power supply circuit board, for radiating a transmission signal supplied from the power supply circuit, and for receiving a reception signal to supply this to the power supply circuit. The resonant circuit is an LC resonant circuit including an inductance device and capacitance devices. The power supply circuit board is a multilayer rigid board or a single-layer rigid board, and between the wireless IC chip and the radiation pattern is connected by DC connection, magnetic coupling, or capacitive coupling.

Abstract: An apparatus for providing dynamic and remote tuning of a cryo-cooled bandpass filter is disclosed. The device includes resonator element and a voltage sensitive element as part of the capacitance in a narrow band filter circuit. A varactor such as a GaAs varactor may be used. Alternatively, a capacitor having a voltage-sensitive dielectric such as SrTiO3 may be used. A computer may be connected to the varactor to provide for automated tuning. The voltage-sensitive capacitor may be integral with the resonator element. The invention provides for remote and dynamic tuning of a narrow bandpass filter while located within its sealed cryo-cooled environment.

Abstract: A method and apparatus are provided for automatic alignment of a notch filter in a receiver. The method comprises the steps of determining a frequency of an interfering signal, monitoring an energy in the interfering signal, tuning the notch filter based on an initial tune value, detecting an energy content in the radio signal after the tuning step, incrementally tuning the notch filter away from the initial tune value while monitoring the energy in the interfering signal, repeating the step of detecting and the step of incrementally tuning until the energy in the interfering signal is minimized, and storing a new tune value as the initial tune value. The notch filter is configured to filter the radio signal. The new tune value indicates a minimized energy in the interfering signal.

Abstract: A sixth coil electrode forming a first coil is electrically connected to a twelfth coil electrode forming a second coil, for example, via a second capacitor electrode in a second capacitor electrode layer. Thus, an induction body has a permeability significantly smaller than the permeability of a magnetic body (for example permeability ?=1). Accordingly, it is possible to minimize the permeability to such a degree that it is possible to ignore the connection between the first coil and the second coil appearing equivalently and to obtain a desired frequency characteristic.

Abstract: An exemplary method is disclosed for disturbance current compensation for an electrical system by a disturbance current compensation device, which electrical system has a voltage source and a series circuit which is connected via a conductor in parallel with the voltage source. The series circuit has an inductance and a capacitance, with the inductance being connected in series with the capacitance via a conductor. To compensate for disturbance currents, the conductor for the connection of the voltage source to the series circuit of the inductance with the capacitance, and/or the conductor of the series circuit between the inductance and the capacitance, can be surrounded by a ring (e.g., a portion of the conductor can be substantially surrounded by the ring) which can be magnetized. The ring includes an air gap of the disturbance current compensation device. A compensation voltage can be applied by magnetization of the ring.

Abstract: A Passive harmonic filter (F) has an input node (B) for connection to a power supply (1), an output node (C) for connection to a load (15, 17) and an intermediate node (A). A first branch (3,4) located between the input node (B) and the intermediate node (A) has at least one first inductance (4). A second branch (11,13) located between the intermediate node (A) and the output node (C) has at least one second inductance (11). A third branch (5, 7, 9) is connected to the intermediate node (A) and has at least one capacitor (9). The first, second and third branch thus build a low-pass T-filter. A damping branch (22, 24; 27, 28) is provided having at least one first resistor (22), where the damping branch is arranged in parallel to the first branch.

Abstract: The present invention relates to a tunable filter device for providing a tunable band pass characteristics for the receive path of a multi-band front-end module. According to the invention is proposed, a distributed, wide-band amplifier with a low-frequency cut-off and a high-frequency cut-off in combination with a LCR network, of which wide-band amplifier the DC blocking capacitors define the low-frequency cut-off of the filter device, whilst the high-frequency cut-off is determined by the cut-off frequency of the artificial input and output transmission lines of the LCR network. In one embodiment, additional capacitors are coupled in parallel to the DC blocking capacitors of the LCR network, switchable by MOS transistors as switching elements. Accordingly, in a certain embodiment it is proposed to allow tuning of the low- and the high-frequency cut-off by programming with a digital control command.

Abstract: There is provided a filter including a first resonator, a second resonator in which an excitation efficiency is reduced more than the first resonator, and an inductor connected in parallel with the second resonator.

Abstract: A current-limiting circuit for limiting switch-on currents or transients includes a switch, a diode, an inductance, an input with a first connection and second connection, and an output with a first connection and second connection. The second connection of the input is connected via the switch to the junction of an inductance and the anode of a diode and via the inductance to the second connection of the output. The cathode of the diode is connected to the first connection of the input and to the first connection of the output. The switch is preferably an electronic switch controlled to provide clocked current limitation.

Abstract: A high frequency module for transmitting and receiving, for example, communication signals of GSM/DCS/PCS/WCDMA systems through a single antenna, is provided at a relatively small size and low cost. The high frequency module includes a diplexer arranged to separate communication signals from the antenna into GSM communication signals in lower frequency bands and POS/DOS/WODMA communication signals in higher frequency bands, a diode switch circuit that is connected to a input and output terminal of the GSM communication signal of the diplexer and is arranged to switch transmission and reception of the GSM communication signal, and a multipoint GaAsIC switch that is connected to the GSM/DCS/PCS/WCDMA communication signals of the diplexer and is arranged to switch transmission and reception of these signals. The high frequency module switches the four types of communication signals by changing the patterns of controls signals VcG, VC1, and Vc2 that are applied to the diode switch circuit and the GaAsIC switch.

Abstract: One or more inductors and one or more capacitors are physically disposed relative to one another in series and are electrically connected to one another in parallel to form a bandstop filter. Chip inductors and chip capacitors having spaced apart conductive terminals are physically arranged in end-to-end abutting relation to minimize electrical potential between adjacent conductive terminals. The bandstop filter may be hermetically sealed within a biocompatible container for use with an implantable lead or electrode of a medical device. The values of the inductors and the capacitors are selected such that the bandstop filter is resonant at one or more selected frequencies, such as an MRI pulsed frequency.

Abstract: A notch filter suitable for attenuating certain frequencies of a radio-frequency signal includes an input for receiving the radio-frequency signal and an output for the output of a portion of the radio-frequency signal, first and second capacitive means, at least one inductor and a negative resistance circuit suitable for compensating the resistive losses of said at least one inductor. The inductor and the first and second capacitive means are placed to produce a resonator and the filter comprises a control device suitable for controlling the negative resistance circuit. The input impedance of the filter comprises a pole and a zero, with the pole depending on the second capacitive means and the zero depending on both the first and second capacitive means. The first and second capacitive means are variable and the control device is suitable for controlling the first and second capacitive means.

Abstract: An electronic component having: a substrate, a lower conductor layer provided on the substrate; an inorganic dielectric film that covers the lower conductor layer; and an upper conductor layer having an upper electrode portion provided on the inorganic dielectric film. The lower conductor layer has a lower electrode portion that together with the upper electrode portion and the inorganic dielectric film constitutes a capacitor, and a coil portion that constitutes an inductor. The entire inorganic dielectric film is formed integrally, and the lower conductor layer is in contact only with the substrate, inorganic dielectric film, and upper conductor layer.

Abstract: A device associated with the control of a tractable filter, including: an induction coil having an inductance Ls, and a resistance Rs; a series resistance rseries having a value determined from a parallel resistance of the induction coil, Lo, the inductance at the resonance frequency, ?0 the resonance frequency, and by taking the lowest resistance value and by deducing rseries from R=rseries+Rs.

Abstract: An EBG (Electromagnetic Bandgap) structure includes a magnetic material portion at least in part. It is preferable to arrange the magnetic material portion close to or, if possible, in contact with a conductor forming the EBG structure, for example, at least a portion of a ground conductor, a conductor producing a capacitance, and/or a conductor producing an inductance, such as a via. Examples of the magnetic material portion include a ferrite plating film, a composite magnetic material layer including magnetic powder and resin binder, and the like.

Abstract: An integrated circuit (IC) inductor structure is provided with transverse electrical interfaces. The inductor structure is formed on at least one IC circuit layer and has a first axis planar to a circuit layer surface, bisecting the inductor into opposite first and second sides. An input interface is formed on the circuit layer and connected to the inductor first side, parallel to a second axis, which is perpendicular to the first axis. An output interface is formed on the circuit layer and connected to the inductor second side, parallel to the second axis. In one aspect, the inductor has a center tap electrical interface parallel to the axis. In another aspect, the inductor includes a three-dimensional (3D) loop formed over a plurality of the circuit layers.

Abstract: In a multilayer bandpass filter, capacitances are produced between a ground electrode provided in a ground electrode formation layer and capacitor electrodes provided in a capacitor electrode formation layer. A plurality of inductor electrodes are defined by via-electrodes and line electrodes such that loop planes of inductor electrodes at least partially overlap each other when seen in a direction in which the inductor electrodes are arranged. The direction of the loop of the inductor electrode of the LC parallel resonator located (at a first stage) at an input end is set to be opposite to the direction of the loop of the inductor electrodes of the LC parallel resonator (at a second stage) adjacent to the inductor electrode of the LC parallel resonator located at the input end.

Abstract: A bandpass filter including one or more metal layers, each layer having a first region and a second region. The filter also includes two or more LC resonators and one or more coupling networks for connecting the two or more LC resonators in parallel. The two or more LC resonators are contained within the first region of the one or more layers and the one or more coupling networks are contained in the second region of the one or more layers.

Abstract: EMC filter, connectable between a supply network and an electric operated appliance to reduce conduction noise between said supply network and said appliance, comprising one voltage regulator having an output terminal whose potential is kept close to the earth potential, in order to reduce the voltage drop, at mains frequency, across a “Y” capacitor or an active shunt module. In this way the leakage current to earth is sensibly reduced. The device of the invention is especially useful in corner-earthed three-phase lines or in conjunction with RCD devices.

Abstract: A band-pass filter includes a plurality of resonators, a feedback capacitive device and a grounding inductance device. A first end of each resonator is connected to a first node, and a second end of each resonator is connected to a second node. The feedback capacitive device is formed on the feedback circuit from the first node to the second node. The grounding inductance device is connected to the second node and ground. In an embodiment, the resonator essentially consists of a capacitive device and an inductance device.

Abstract: A filter includes: a converter circuit, provided with a single-type common terminal and two balanced terminals, for performing conversion between a balanced line and an unbalanced line; two filter units coupled to each of the balanced terminals of the converter circuit and allowing passage of a signal in a pass band; and a bridging capacitor arranged to extend across the converter circuit and one of the filter units in a bridging manner, wherein the inductance of an opposite-side line of one of the filter units relative to the converter circuit is electromagnetically coupled to the inductance of a line coupling the other filter unit and the converter circuit.

Abstract: A composite right/left-handed line device includes plural electrodes, plural dielectric substances and plural magnetic substances. The plurality of electrodes each include a pair of electrode plates, and a connection piece connected to the pair of electrode plates. The plurality of electrodes are disposed at regular intervals in a thickness direction between a pair of input terminals and a pair of output terminals. The plurality of dielectric substances are interposed between opposite surfaces of the pairs of electrode plates of adjacent two of the electrodes. The plurality of magnetic substances are disposed adjacently to the dielectric substances, respectively. The plurality of magnetic substances are interposed between opposite surfaces of the connection pieces of adjacent two of the electrodes.

Abstract: There is provided a multi-layered band pass filter capable of improving a stop characteristic out of a pass band and reducing the entire size of the filter.

Abstract: The present invention provides a two-dimensional left-handed metamaterial that functions as a two-dimensional electromagnetic wave propagation medium in which the equivalent permittivity and permeability of the medium are both negative, exhibits superior low-loss, broadband characteristics as a left-handed material, and has a simple constitution, enabling low-cost manufacture. The two-dimensional left-handed metamaterial is formed by disposing unit structures 10 constituted by a conductor regularly on a plane, the unit structure including: a columnar first prism, a central axis of which is oriented perpendicularly to the plane; a columnar second prism that has a central axis in an identical direction to the first prism and is disposed at a remove from the first prism in a central axis direction; and a connecting body for electrically connecting the first prism and the second prism to each other.

Abstract: An LC composite component capable of reducing an overall size while keeping a Q-value of a resonator at a high level and increasing coupling flexibility of resonators includes two capacitor electrodes and two input/output terminal electrodes extending therefrom provided on a first dielectric layer. A ground electrode and another capacitor electrode are provided on second and sixth dielectric layers, respectively. Two substantially linear line electrodes are provided on a third dielectric layer. Two substantially U-shaped line electrodes are provided on a fourth dielectric layer. Two substantially crank-shaped line electrodes are provided on a fifth dielectric layer. Six via electrodes arranged to connect ends of respective line electrodes are provided on the third, fourth, and fifth dielectric layers. These via electrodes and line electrodes constitute electrodes of a double helix structure.

Abstract: A monolithically integratable circuit arrangement is provided, which has at least one inductor, formed as a conductor loop, and at least one capacitor, connected to the conductor loop. According to the invention, the circuit arrangement comprises (a) at least one first conductor loop placed in at least one first metallization level and having a first DC terminal for applying a first DC potential, (b) at least one second conductor loop placed in at least one second metallization level and having a second DC terminal for applying a second DC potential, (c) at least one metal-isolator-metal capacitor with a capacitor plate, which is placed in a third metallization level between the first and second metallization level, and (d) at least one metallic connecting means placed between the capacitor plate and the first conductor loop, said means which connects the capacitor plate in an electrically conducting manner to the first conductor loop.

Abstract: A packaging material includes an electromagnetic coupling module for an RFID system, in which a radio IC chip is protected from external shock and environmental change without affecting the planarity of the packaging material, the assembly including an electromagnetic coupling module is facilitated, and the radiation characteristics are satisfactory. A packaging material includes a liner and a wave-shaped core material, wherein an electromagnetic coupling module is arranged inside of the packaging material. The electromagnetic coupling module includes a radio IC chip and a feeder circuit board, on which the radio IC chip is mounted, the feeder circuit board including a resonant circuit that includes an inductance element. The packaging material is made of a dielectric, wherein the dielectric and the electromagnetic coupling module are electromagnetically coupled to transmit/receive high frequency signals.

Abstract: A resonant circuit has two parallel resonant branches and one assistant inductor connecting the two resonant branches. Each resonant branch has a series capacitor and a series inductor connected in series. The other end of the series inductor is for connecting to a primary side of a transformer unit. The resonant circuit can provide two characteristic resonant frequencies fr and fm, so that a resonant power converter using the resonant circuit has an operating frequency fs that satisfies fs>fr or fm<fs<fr. The combination of the two resonant branches and the assistant inductor can reduce the frequency switch range of the resonant power converter within a specific voltage gain.

Abstract: An electronically tuned, absorptive, low-loss notch filter with high RF power handling capability is obtained using a four-port quadrature hybrid coupler connected to a matched pair of band pass resonator devices and resistive terminations. The notch filter design uses series-only tuning elements for the band pass resonator devices to raise the RF power handling of the band pass resonators far above conventional techniques while also being tunable at high speeds. The notch filter architecture and method can be used for interference cancellation in a wide range of wireless technologies, such as cellular phone, wireless routers, hand-held radios, satellite communications, and any other environments where there are a number of wireless technologies in close signal proximity.

Abstract: An electromagnetic interference eliminating apparatus includes a multi-stage filter that is composed of inductors, capacitors and resistors, and an active filter. The multi-stage filter receives an input signal and provides an eliminating band to eliminate the noise in the input signal. The active filter is connected with the multi-stage filter for buffering the input signal that has been eliminated and exactly outputting an output signal.

Abstract: In a configuration with at least one RF component disposed in a signal path and including a ground connection to an external circuit environment, a coupling element is provided which electromagnetically couples to at least part of the ground connection and at the same time decouples a coupling current. By suitably feeding this coupling current back into the signal path of the component, the negative influence of the inductance of the ground connection on the signal path is thus compensated for.

Abstract: Tunable matching network topologies are disclosed. A network in accordance with the present invention comprises at least one inductor, and at least one tunable capacitor, in parallel with the inductor, wherein the at least one tunable capacitor tunes the at least one inductor self-resonant frequency.

Abstract: A capacitor device is provided. The capacitor device includes at least one capacitor. The capacitor device also includes a first capacitor and a first filter coupling the first capacitor and a conductive region, wherein the first capacitor has a first resonance frequency and the first filter is configured to operate at a first frequency band covering the first resonance frequency.

Abstract: The present invention provides a surface mount design (SMD) coupling filter device with a fixed coupling coefficient having a pair of hollow coils. Theoretically, coupling coefficients of two hollow coils may vary with the parameter such as distance, number of windings, inner radius, wire size, medium coefficient. When a desired coil coupling distance is derived from the above parameters, a pair of hollow coils then is fastened fixed by either a house fastening approach or an adhesive injection fastening approach, such that the desired coil coupling distance can be fixed by using an adhesive with a specific medium coefficient.