Abstract: A demultiplexer has a common terminal, a transmission terminal, and a reception terminal, and furthermore includes a transmission filter connected between the common terminal and the transmission terminal, a reception filter connected between the common terminal and the reception terminal, and a phase shift circuit connected in series to the reception filter connected between the common terminal and the reception terminal. A node on the line from the phase shift circuit to the common terminal or the transmission terminal, and a node on the line from the phase shift circuit to the reception terminal are coupled via a reactance. Accordingly, it is possible to fundamentally reduce or eliminate the situation in which transmission signals from the transmission filter arrive at the reception circuit, and improve isolation.

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 step attenuator circuit is mounted on a printed circuit board and has a highpass filter network passing high frequency signals and a lowpass filter network passing low frequency signals. The lowpass network presents a high shunt reactance to the high frequency signals. The lowpass network includes an attenuator network. The attenuator network attenuates the low frequency signals by a specified amount. Parasitic capacitance exists between the highpass network and the attenuator network, causing an amount of electrical energy from the high frequency signals to be absorbed by the attenuator network. A first capacitive circuit is used to compensate for parasitic capacitance. The first compensation circuit is connected across the attenuator network and is coupled to the parasitic capacitance. Consequently, the amount of electrical energy from the high frequency signals absorbed by the attenuator network is reduced, and, as a result, the insertion loss of the step attenuator is reduced.

Abstract: The present invention relates to a low pass filter incorporating coupled inductors to enhance stop band attenuation. In one embodiment, the coupled inductors are provided along with various capacitors to provide for superior performance within a smaller surface area of a semiconductor or ceramic integrated device. In a further specific embodiment, the capacitors are formed on an integrated device within an area on which entirely intertwined inductors are formed. In another embodiment, at least one further pair of coupled inductors is included to create additional frequency attenuation notches, as well as a wide stop-band.

Abstract: A band rejection filter capable of reducing harmonics includes a first signal end, a second signal end, a high pass filter coupled between the first signal end and the second signal end for performing high pass filtering on signals transmitted between the first signal end and the second signal end, and a low pass filter coupled between the first signal end and the second signal end for performing low pass filtering on signals transmitted between the first signal end and the second signal end. The low pass filter includes a plurality of non-magnetic-core inductors coupled in a sequence between the first signal end and the second signal end, and a plurality of capacitors respectively coupled between an intersection of adjacent non-magnetic-core inductors of the plurality of non-magnetic-core inductors and a ground end.

Abstract: A first passive part forms a second parallel resonance circuit having a resonance frequency near the passing band among a first to a third parallel resonance circuit as follows. That is, the second parallel resonance circuit is formed at a position farthest from a first shield electrode and farthest from a second shield electrode in a region sandwiched by the first shield electrode and the second shield electrode in a dielectric substrate (in this example, on the main surface of a seventh dielectric layer and the main surface of an eighth dielectric layer located at a center portion in the layering direction of the region.

Abstract: A combined matching and harmonic rejection circuit with increased harmonic rejection provided by a split resonance for one or more of the capacitive or inductive elements of the circuit. At a fundamental frequency, the circuit comprises an inductive series arm with capacitive shunt arms. The capacitance of a shunt arm may be provided by two or more parallel paths, each having a capacitor and an inductor in series so that, in addition to providing the effective capacitance necessary for impedance matching at the fundamental frequency, two separate harmonics represented by the series resonances of the parallel paths are rejected. In this manner, an extra null in the circuit's stop-band may be achieved using the same number of shunt elements necessary to achieve impedance matching at the fundamental frequency.

Abstract: A switching capacitor generation circuit which reduces the on-resistance and parasitic capacitance of a switch element and improves the operation properties of the switch element. The switching capacitor generation circuit, which has first and second output terminals, includes a first capacitor coupled to the first output terminal, a second capacitor coupled to the second output terminal, and a single switch element coupled between the first and the second capacitors.

Abstract: A band pass filter includes an original circuit. An interaction of at least two of components of the original circuit produces at least a mutual capacitor or at least a mutual inductor, which constitutes a resonance circuit with the original circuit to produce at least a transmission zero for increasing the attenuation rate of the stop band.

Abstract: An agile frequency converter provides IF-RF level exchange and notch filtering. System noise and spurious levels generated by channel frequency conversion is reduced in applications requiring broadband combining of frequency converters to form multichannel composite signal. A pair of varactor banks is connected in an arrangement whereby varactor pairs are connected in parallel and capacitor pairs are connected in anti-parallel. Tuning is achieved by circuitry for tuning first and second varactors.

Abstract: The present invention relates to an antenna-filter module for transferring radio frequency electromagnetic signals between the ambient air and an electronic circuit. The module includes an antenna element and at least two integrated band pass filter disposed adjacent to said antenna element. The antenna element is arranged as a joint antenna element, having a substantially greater bandwidth than each filter and providing a number of antenna-filter combinations within the module. The joint antenna element is arranged in close proximity to a first resonator of each filter in the module so as to provide an electromagnetic coupling to the resonators of each filter and a differentiated, specific pass band for the respective antenna-filter combination. Each filter is provided with a coupling member for coupling to an electronic circuit, such as an amplifier.

Abstract: A miniature resonating marker assembly that includes, in one embodiment, a ferromagnetic core, a wire coil disposed around the core, and a capacitor connected to the wire coil adjacent to the magnetic core. The core, coil, and capacitor form a signal element that, when energized, generates a magnetic field at a selected resonant frequency. The magnetic field has a magnetic center point positioned along at least one axis of the signal element. An inert encapsulation member encapsulates the signal element therein and defines a geometric shape of the resonating marker assembly. The geometric shape has a geometric center point substantially coincident with the magnetic center point along at least a first axis of the signal element. The shape and configuration of the assembly also provides for a miniature signal element specifically tuned to resonate at a selected frequency with a high quality factor.

Abstract: A dual bandstop filter affects frequencies in a lower passband, first and second stopbands separated by a middle passband, and an upper passband. The filter includes two legs. In one version, one leg is a highpass filter while the other leg is a bandstop filter outputting into a lowpass filter. In a second version, one leg is a lowpass filter while the other leg is highpass filter outputting into a bandstop filter. The first version is preferred when the upper value of the lower passband is around 100 MHz or less, while the second version is preferred when the upper value of the lower passband is around 100 MHz or more. In a third version, one leg is a highpass filter while the other leg is a bandstop filter sandwiched between two lowpass filters, preventing second resonances from the lowpass filter from interfering with desired frequencies in the upper passband.

Abstract: A dual bandstop filter affects frequencies in a lower passband, first and second stopbands separated by a middle passband, and an upper passband. The filter includes two legs. In one version, one leg is a highpass filter while the other leg is a bandstop filter outputting into a lowpass filter. In a second version, one leg is a lowpass filter while the other leg is highpass filter outputting into a bandstop filter. The first version is preferred when the upper value of the lower passband is around 100 MHz or less, while the second version is preferred when the upper value of the lower passband is around 100 MHz or more. In a third version, one leg is a highpass filter while the other leg is a bandstop filter sandwiched between two lowpass filters, preventing second resonances from the lowpass filter from interfering with desired frequencies in the upper passband.

Abstract: According to one exemplary embodiment, a selectable notch filter includes a transmission line, a bias circuit, and a switch for selectably coupling the transmission line to ground. In one embodiment, the switch is a PIN diode. The selectable notch filter can selectably suppress a first frequency from being output when the transmission line is coupled to ground. Additionally, the selectable notch filter can selectably suppress a second frequency from being output when the transmission line is not coupled to ground. In one embodiment, the first frequency is approximately equal to a multiple of two of the second frequency. In one embodiment, the selectable notch filter can utilize more than one transmission line.

Abstract: The present invention relates to a low pass filter incorporating coupled inductors to enhance stop band attenuation. In one embodiment, the coupled inductors are provided along with various capacitors to provide for superior performance within a smaller surface area of a semiconductor or ceramic integrated device. In a further specific embodiment, the capacitors are formed on an integrated device within an area on which entirely intertwined inductors are formed. In another embodiment, at least one further pair of coupled inductors is included to create additional frequency attenuation notches, as well as a wide stop-band.

Abstract: The electrically tunable inductive device includes an electromagnet including an electromagnet core and a bias or tuning coil cooperating therewith to define opposing magnetic poles for generating a quiescent magnetic field that may be varied. An inductor is tunable based upon the variable magnetic field and includes an inductor core having a toroidal shape and fixed at a position adjacent the opposing magnetic poles of the electromagnet, and an inductor or signal coil is around at least a portion of the inductor core. The electromagnet core may include a pair of opposing legs and a bight portion therebetween defining a horseshoe shape. The inductor core may be positioned between ends of the opposing legs of the electromagnet core, and the tuning coil may surround the bight portion of the electromagnet core. The electrically tunable inductive device may have the combination of fine precision, high speed and high power handling, useful for tunable RF filters.

Abstract: The present invention reduces distortion in variable capacitance devices by connecting a circuit to the variable capacitance devices that has low impedance at predetermined frequencies to suppress those frequencies and also suppress harmonics and mixing products resulting from mixing of various frequencies.

Abstract: A bandpass filter having a bandpass width appropriate for UWB, a high frequency module including the bandpass filter, and radio communication device including both is provided. The bandpass filter including a laminate composed of a plurality of dielectric layers 11; first and second ground electrodes arranged on the bottom and top surfaces, respectively, of the laminate; resonance electrodes 30a, 30b, and 30c arranged in an inter-digital structure on a first inter-layer surface of the laminate, one end of each of the resonance electrodes being grounded; an input coupling electrode 40a arranged on an inter-layer surface different from the first inter-layer surface of the laminate facing the resonance electrode 30a of the input stage in the inter-digital type; and an output coupling electrode 40b arranged on an inter-layer surface different from the first inter-layer surface of the laminate to face the resonance electrode 30b of the output stage.

Abstract: A dual bandstop filter affects frequencies in a lower passband, first and second stopbands separated by a middle passband, and an upper passband. The filter includes two legs. In one version, one leg is a highpass filter while the other leg is a bandstop filter outputting into a lowpass filter. In a second version, one leg is a lowpass filter while the other leg is highpass filter outputting into a bandstop filter. The first version is preferred when the upper value of the lower passband is around 100 MHz or less, while the second version is preferred when the upper value of the lower passband is around 100 MHz or more. In a third version, one leg is a highpass filter while the other leg is a bandstop filter sandwiched between two lowpass filters, preventing second resonances from the lowpass filter from interfering with desired frequencies in the upper passband.

Abstract: Multiple tank elements disposed along a common axis and multiple conductive pads disposed along opposing sides of the tank elements define a serpentine transmission path. The tank elements, each having a capacitor and an inductor in parallel communication, define respective portions of the serpentine transmission path that cross the common axis. In a circuit element having multiple tank elements defining a transmission path in which each tank element is preceded or followed by a next neighbor tank element, inductors of next neighbor tank elements are structured to generate directionally opposing magnetic fields upon passage of electrical current progressing along the transmission path.

Abstract: A high-frequency switching module in which a high-frequency switch including a diode, which functions as a switching device, and a high-frequency filter including inductors and a capacitor are integrated with each other. The inductor defining a ?-type high-frequency filter is connected directly and in series to the diode. By inserting the inductor, the cut-off frequency of a Chebyshev-type low-pass filter circuit produced when the diode is turned ON can be shifted to a lower frequency side, and also, the ripple can be suppressed to a small level.

Abstract: It is possible to generate an additionally attenuation pole in a laminate type band pass filter without adding an attenuation circuit and improve the attenuation characteristics of the laminate type band pass filter by independently controlling the frequencies of the attenuation poles. A diplexer is realized by using at least such a filter.

Abstract: In an isolation trap circuit of the present invention, a PIN diode PD and an inductor L are connected in parallel to a first terminal 61, and a capacitor C1 is connected in series to the inductor L, while the PIN diode PD and the capacitor C1 are connected in parallel to a second terminal 62. The isolation trap circuit is characterized in that a capacitor C2 is further connected and grounded between the first terminal 61 and the inductor L, or between the inductor L and the capacitor C1, or between the capacitor C1 and the second terminal 62.

Abstract: An ultra-high-frequency notch filter (100) comprises a capacitor (102) defining a conductive trace (106) on its body (103) and extending between its terminals (104). The trace has an inductance that forms a parallel LC circuit with the capacitance of the capacitor. When mounted on a printed circuit board (120) to connect two segments of a signal line (124), the notch filter and a ground plane (122) of the PCB form a virtual conductive loop having an inductance and a capacitance whose product is the center frequency of the notch of the notch filter. The center frequency is tuned by varying the width of the trace.

Abstract: A dual bandstop filter affects frequencies in a lower passband, first and second stopbands separated by a middle passband, and an upper passband. The filter includes two legs. In one version, one leg is a highpass filter while the other leg is a bandstop filter outputting into a lowpass filter. In a second version, one leg is a lowpass filter while the other leg is highpass filter outputting into a bandstop filter. The first version is preferred when the upper value of the lower passband is around 100 MHz or less, while the second version is preferred when the upper value of the lower passband is around 100 MHz or more. In a third version, one leg is a highpass filter while the other leg is a bandstop filter sandwiched between two lowpass filters, preventing second resonances from the lowpass filter from interfering with desired frequencies in the upper passband.

Abstract: A radio frequency (“RF”) harmonic filter circuit as disclosed herein is fabricated using integrated passive device (“IPD”) technology. The RF harmonic filter circuit is configured to provide second, third, and fourth harmonic rejection while providing good input and output impedance matching. The RF harmonic filter circuit employs only one IPD loop inductance (preferably used for a second harmonic resonance circuit), which results in a significant die/package size reduction. The RF harmonic filter circuit also employs a combined circuit that performs input and/or output impedance matching and third harmonic rejection.

Abstract: A tank filter is provided for a lead wire of an active medical device (AMD). The tank filter includes a capacitor in parallel with an inductor. The parallel capacitor and inductor are placed in series with the lead wire of the AMD, wherein values of capacitance and inductance are selected such that the tank filter is resonant at a selected frequency. A passageway through the tank filter permits selective slidable passage of a guide wire therethrough for locating the lead wire in an implantable position. The Q of the inductor may be relatively maximized and the Q of the capacitor may be relatively minimized to reduce the overall Q of the tank filter to attenuate current flow through the lead wire along a range of selected frequencies. In a preferred form, the tank filter is integrated into a TIP and/or RING electrode for an active implantable medical device.

Abstract: A cancellation circuit to remove the anti-resonance signal from a resonator. Micro-mechanical and surface and bulk acoustic wave resonators include an anti-resonance in an output signal. This has an undesirable effect on certain types of systems in their function and performance. An anti-resonance cancellation circuit removes the anti-resonance from the output of the resonators by providing a signal which is subtracted from the output of the resonator. The cancellation circuit includes a capacitor which is matched to the static capacitance of the resonator. The loads of the resonator and cancellation network are also matched.

Abstract: A HIFU compatible receiving coil for MRI radio-frequency signals has an antenna and an amplifier connected to each other, each for receiving and amplifying MRI radio-frequency signals, and a filter positioned in front of the amplifier for filtering the HIFU low frequency signals received by the antenna at the same time as receiving the MRI radio-frequency signals. In a method for receiving the MRI radio-frequency signals and then for amplifying the same, the received MRI radio-frequency signals are filtered before being amplified, so as to filter out the HIFU signals received at the same time as the MRI radio-frequency signals. By this filtering, the HIFU signals among the HIFU signals and MRI radio-frequency signals simultaneously received by the antenna are filtered out at the same time as the HIFU treatment, and the remaining MRI radio-frequency signals are connected into the MRI system after being amplified by the amplifier for real-time imaging.

Abstract: A printed circuit board (PCB) including a notch filter, or other suitable filter, is implemented in a communication device for attenuating RFI in transmissions sent from the communication device. The filter includes filter line that runs between at least two conductor layers on the PCB, in a substantially repeating pattern, which maximizes the space available on each conductor layer for additional uses.

Abstract: Method and apparatus for protecting a filter trap that is utilized in a coaxial cable system against theft of service. A barrier is mounted inside a filter housing which includes a pair of end connectors that are aligned along a common axis. The barrier is mounted on one or both end faces plate or isolation shield for intercepting a cutting tool moving along the axis to direct the tool away from the axis. At least one opening in the plate adjacent to the barrier engages the intercepted cutting tool and further directs the tool away from the axis causing the tool to break or to prevent the formation of a passage between the end connectors.

Abstract: The present invention is to provide a narrow bandpass filter installed on a circuit board for suppressing a high-frequency harmonic wave, which uses a metal microstrip method to directly build a microstrip circuit corresponding to a narrow bandpass filter on a circuit board of a wireless communication product and uses an interdigital finger method to lay a capacitor microstrip of the microstrip circuit on the circuit board to avoid the capacitor microstrip occupying too much area of the circuit board and maximizes the usable space of the circuit board, so that the wireless communication product can suppress a second or higher harmonic spurious noise of the wireless communication product without using an additional high-frequency filter, and thus can greatly lower the manufacturing cost of the wireless communication product and effectively reduce the electromagnetic interference.

Abstract: The present invention provides a tunable bandpass filter and method thereof. In a preferred embodiment, the tunable bandpass filter uses variable ferro-electric capacitors to adjust both the passband and the notch across the normal operating range of a wireless communications device. The tunable bandpass filter is capable of providing a tuning range over a desired frequency range with low I.L. and high out-of-band rejections.

Abstract: A coaxial capacitor is inserted in a coaxial cable in a predetermined position. A housing is provided as a ground conductor path in order to establish conduction between two external conductors in portions of the coaxial cable which are separated by the inserted coaxial capacitor. Inside the housing, a resonator formed by a dielectric coaxial resonator or the like, the coaxial capacitor, and a connecting conductor are accommodated.

Abstract: A circuit for matching the impedance of a narrow-band resonator filter presented to a port over a broad range of frequencies employs a second resonator that has substantially the same transfer characteristic as the resonator filter. The resonator filter is isolated from the output port using a resonator having a dual characteristic that behaves as a short circuit in the pass-band of the resonator filter, and is an open circuit in the stop-band of the resonator filter. The second resonator is isolated from the port using a resistor that has a value on the order of the ideal or desired impedance to be presented at the port. The circuit provides an impedance at the port that is approximately equal to the desired impedance in the stop-band, and an impedance that is slightly degraded in the pass-band, and particularly at the on-frequency of the resonator filter.

Abstract: An electrical filter disconnects a connecting pin when uninstalled. A first filter section includes a first set of electrical filter components, while a second filter section includes a second set of electrical filter components, with the connecting pin connecting the two filter sections. An electrical isolation shield disposed between the first and second filter sections includes a first plate and a second plate which are rotatable with respect to each other, wherein the first plate includes a first cutout portion and the second plate includes a second cutout portion. The first plate is locked to the first filter section while the second plate is locked to the second filter section. When the electrical filter is unscrewed from the port, the first filter section rotates with respect to the second filter section such that the connecting pin breaks electrical connection between the first filter section and the second filter section.

Abstract: Method and apparatus for protecting a filter trap that is utilized in a coaxial cable system against theft of service. A shield is mounted inside the filter trap which contains a pair of end connectors that are aligned along a common axis. The shield has two parallel end faces that are perpendicularly aligned with regard to the common axis. A barrier is mounted on one or both end faces for intercepting a cutting tool moving along the axis to direct the tool away from the axis causing the tool to break or to prevent a passage to be completed between the end connectors.

Abstract: A novel transceiver is provided which allow for either a transmitter or receiver to be dynamically switched between two different frequency bands by use of a novel switchable lowpass filter.

Abstract: An integrated RF filter for use at microwave frequencies comprising: an integrated circuit inductor with connected integrated circuit capacitors, arranged as a tank circuit, and an integrated circuit shunt resistor; the inductor, capacitors and resistor being interconnected in a bridge-T filter arrangement.

Abstract: A high-frequency module is connected to a transmitting circuit (TX), a receiving circuit (RX) and an antenna (ANT) to control the connections between the transmitting circuit (TX) and the antenna (ANT) and between the receiving circuit (RX) and the antenna (ANT). The module comprises means (2) for controlling transmitted signals, which includes a first phase-shift circuit (5) and a high-frequency amplifier (4) provided between the antenna (ANT) and the transmitting circuit (TX). The high-frequency amplifier (4) and the first phase-shift circuit (5) are integrated into a module composed of a plurality of dielectric layers.

Abstract: An “inside out” process is used to make RF antennas and components or higher frequency components and/or optics. An electroformed single or multi layer of metal, such as copper, is applied to a reusable or disposable mandrel. Additional metal or composite components and/or pieces may be attached to the electroform by means of further electroforming, and/or applying adhesive and/or soldering. Any composite material (for example, fiberglass or carbon fiber reinforced plastic) is then applied selectively or uniformly around the electroform and/or additional components for structural reinforcement, and/or enhancement of thermal stability and/or thermal conductivity. The mandrel is then removed by physical or chemical means. Adhesion over temperature and humidity extremes, surface finish, uniform metalization thickness, and surface electrical conductivity are all vastly improved over equivalent electroplated composites.

Abstract: The present invention relates to a control system for selectively supplying electrical power in a remote environment. The system comprises a plurality of electrical circuits, each designed to operate over a unique frequency passband. Power transmitted within the frequency passband of a circuit is filtered through that circuit to power a corresponding remote device. One or more remote devices can be simultaneously powered by transmitting power within the frequency passbands of the corresponding circuits. It is advantageous to design relatively narrow passbands to accommodate a relatively large number of circuits and corresponding devices for remote operation and a triac, rectifier or other suitable turn-on gate can be incorporated into each circuit to effectively control the width of the frequency passband of each circuit. Alternatively, an operational amplifier could be used.

Abstract: A filter assembly for use in the CATV industry includes a circuit formed by components mounted upon at least one circuit board with a plurality of paths or traces on the board connecting each section of the circuit to a member at ground potential. The grounding member may be a grounding bus on the circuit board which is in contact with a housing wherein the circuit board is mounted, or the paths may extend from a circuit component to contact the housing directly. The paths are kept to a very short length, preferably not more than 2.5 millimeters and in no case longer than 5 millimeters. This avoids the presence of inductive and/or resistive parasitics in the paths, thereby avoiding the degradation of performance typical in comparable prior art filter circuits, particularly at higher frequencies, e.g., above about 300 MHz. In the preferred embodiment grounding buses in the form of elongated strips extend along opposite edge portions of the board.

Abstract: A filter circuit directed primarily to use in the CATV industry includes at least one frequency dependent component, such as an RF choke, capacitor or inductor, for attenuating signals over at least a portion of the frequency range of signals which pass through the filter. In a typical application, signals are transmitted and received in both forward and return paths at each end of a multi-channel, two-way communication system. Signals in the frequency range of the return path, or of both paths, are attenuated by a desired amount, which is essentially constant over the frequency range of attenuation. In any case, the circuit component providing the attenuation is frequency dependent, thus providing a number of advantages, such as reducing the number of circuit components, reducing filter size and cost, and/or increasing the filter's electric surge and power handling capabilities.

Abstract: An LC high-pass filter circuit device includes an inductor defined by via holes formed in adjacent insulating sheets which are connected in the direction of stacking of the sheets so as to define a single trap inductor. Inductor via holes formed in another insulating sheet define separate high-pass filter inductors. The trap inductor and the high-pass filter inductors have axes which extend substantially perpendicularly to the planes of the insulating sheets. Each of the high-pass circuit inductors defines, in combination with a high-pass filter capacitor, a high-pass filter circuit, while the trap inductor defines, in combination with a capacitor, a trap circuit. The high-pass filter circuits and the trap circuit in combination define a small-sized LC high-pass filter circuit device which exhibits high Q value and which excels in frequency characteristics, as well as a laminated LC high-pass filter device, a multiplexer and a radio communication apparatus incorporating the LC high-pass filter circuit device.

Abstract: A bandstop filter for use in CATV applications is formed by a pair of diplexers, a lowpass filter and a highpass filter. Signals having a frequency range of, e.g., 0-3 GHz enter at a first node connected to the inputs of both the lowpass and highpass filters. Signals having frequencies below a first, predetermined value pass through the lowpass filter, and signals having frequencies above a second, predetermined value pass through the highpass filter with signals having frequencies between the first and second values being blocked, i.e., “stopped.” The outputs of both the lowpass and highpass filters are connected to the second diplexer at a second node which is connected to the single output.

Abstract: A filter circuit directed primarily to use in the CATV industry includes at least one frequency dependent component, such as an RF choke, capacitor or inductor, for attenuating signals over at least a portion of the frequency range of signals which pass through the filter. In a typical application, signals are transmitted and received in both forward and return paths at each end of a multi-channel, two-way communication system. Signals in the frequency range of the return path, or of both paths, are attenuated by a desired amount, which is essentially constant over the frequency range of attenuation. In any case, the circuit component providing the attenuation is frequency dependent, thus providing a number of advantages, such as reducing the number of circuit components, reducing filter size and cost, and/or increasing the filter's electric surge and power handling capabilities.

Abstract: A multi-layer wiring board comprises an insulating substrate having, on a central part of its top surface, a semiconductor device mounting portion and having, on its under surface, an external electrode. The insulating substrate includes a multilayered wiring having a first group of parallel wiring lines; a second group of parallel wiring lines arranged orthogonal thereto; and a group of through conductors for providing electrical connection therebetween. Power is supplied from the external electrode to the semiconductor device through built-in capacitors formed therewithin. The built-in capacitors are connected in parallel that have different resonance frequencies within a range from an operating frequency band for the semiconductor device to a frequency band for a harmonic component, and at an anti-resonance frequency occurring between the different resonance frequencies, a composite impedance is equal to or below a predetermined value.

Abstract: A multilayer band separator with a grounding parasitic capacitor. The separator includes a quasi-highpass filter, a semi-lumped lowpass filter and a phase shifter. The quasi-highpass filter includes a third capacitor connected to an input signal, a fourth capacitor with one end connected to the third capacitor and the other end connected to ground, an inductive element with one end connected to ground and the other end connected to the connection point of the third and fourth capacitors, and a second capacitor with one end connected to the connection point of the third capacitor, the fourth capacitor and the inductive element and the other end connected to a second output to pass a high-frequency output signal. The phase shifter is a transmission line element connected to the input signal.