Abstract: A signal processing device includes a first acoustic resonator, a second acoustic resonator disposed on the first acoustic resonator, and a coupling layer between the first and the second acoustic resonators. The first acoustic resonator has a first electrical impedance and a first resonance frequency and includes a first set of electrodes, and a first piezoelectric layer having a first thickness, disposed between the first set of electrodes. The second acoustic resonator has a second electrical impedance and a second resonance frequency, and includes a second set of electrodes, and a second piezoelectric layer having a second thickness, wherein the second piezoelectric layer is disposed between the second set of electrodes. The first electrical impedance at a passband frequency of the device substantially differs from the second electrical impedance at the passband frequency of the device. The first and second resonance frequencies are substantially different from each other.

Abstract: A component is designed to work with acoustic waves. Embodiments have an improved temperature gradient of the frequency range and have increased performance strength. To this end, the component includes a stack of layers having a lower bonding layer, an electrode layer, an upper bonding layer, a compensation layer, and a trimming layer.

Abstract: A ladder filter including a series arm resonator and a parallel arm resonator disposed on the same common piezoelectric substrate achieves improved miniaturization. The ladder filter includes series arm resonators and parallel arm resonators, which include elastic wave resonators, and are disposed on the same common piezoelectric substrate, at least one parallel arm resonator of the series arm resonators and the parallel arm resonators includes a first resonator and a second resonator electrically connected in parallel to each other, and the first resonator and the second resonator are arranged in parallel or substantially in parallel in a direction perpendicular or substantially perpendicular to an elastic wave propagation direction, on one side outside one series arm resonator of remaining resonators in the elastic wave propagation direction thereof.

Abstract: A bank of nano electromechanical integrated circuit filters. The bank of integrated circuit filters comprising a silicon substrate; a sacrificial layer; a device layer including at least two resonators, wherein the at least two resonators include sub-micro excitable elements and wherein the at least two resonators posses a fundamental mode frequency as well as a collective mode frequency and wherein the collective mode frequency of the at least two resonators is determined by the fundamental frequency of the sub-micron elements. At least one switch connects to the bank of integrated circuit filters.

Abstract: A surface acoustic wave (SAW) filter device includes an input port for receiving an unbalanced signal, a pair of input/output ports, a first SAW filter for receiving the unbalanced signal from the input port and outputting balanced signals to the pair of input/output ports, a second SAW filter for receiving the balanced signals output from the pair of input/output ports and outputting balanced signals, and a pair of output ports for outputting the balanced signals output from the second SAW filter. The first SAW filter includes a first longitudinally-coupled SAW resonator having a first unbalanced signal input port and first and second balanced signal output ports, and a second longitudinally-coupled SAW resonator having a second unbalanced signal input port and third and fourth balanced signal output port. The first and second unbalanced signal input ports are electrically connected to the input port.

Abstract: A circuit substrate includes: a laminate substrate in which a conductive layer and an insulating layer are laminated; a filter chip that has an acoustic wave filter and is provided inside of the laminate substrate; and a chip component that is provided on a surface of the laminate substrate and is connected to the filter chip, at least a part of the chip component overlapping with a projected region that is a region of the filter chip projected in a thickness direction of the laminate substrate.

Abstract: A ladder-type surface acoustic wave filter includes a first series resonator having the lowest resonance frequency among a plurality of series resonators; and a second series resonator having a resonance frequency higher than the first series resonator. The film thickness of a dielectric film in the region where the first series resonator is formed is larger than that of a dielectric film in the region where the second series resonator is formed.

Abstract: An elastic wave surface acoustic wave duplexer includes an antenna terminal, a transmission filter, a reception filter, and a plurality of elastic wave resonators connected in series between the antenna terminal and the reception filter. The reception filter is a longitudinally coupled resonator-type surface acoustic wave filter including a plurality of IDT electrodes and arranged along a propagation direction of elastic wave. A combined capacitance of the plurality of surface acoustic wave resonators is smaller than a capacitance of the IDT electrodes and included in the plurality of IDT electrodes and connected to the antenna terminal.

Abstract: A filter includes: a plurality of piezoelectric thin film resonators, each having a multilayered film including a lower electrode located on a substrate, a piezoelectric film located on the lower electrode, and an upper electrode located on the piezoelectric film so as to face the lower electrode, wherein at least two piezoelectric thin film resonators have thick film portions, in each of which the multilayered film is thicker in at least a part of an outer peripheral portion than in an inner portion of a resonance region in which the lower electrode and the upper electrode face each other across the piezoelectric film, and lengths of the thick film portions from edges of the resonance regions are different from each other in the at least two piezoelectric thin film resonators.

Abstract: A duplexer includes: a first filter of which first and second ends connect to a common terminal and a first terminal respectively; and a second filter having a passband higher than that of the first filter, a first end and second end thereof connecting to the common terminal and a second terminal respectively, wherein a phase shifter is located neither between the first filter and the common terminal nor between the second filter and the common terminal, the second filter is a ladder-type filter including piezoelectric thin film resonators connected in a ladder shape, a propagation constant in a direction perpendicular to a thickness direction of a piezoelectric thin film in the piezoelectric thin film resonator is a real number at frequencies lower than a resonance frequency of the piezoelectric thin film resonator, and a resonator at a first stage is a parallel resonator in the second filter.

Abstract: A filter includes: a coupled multi-mode acoustic wave filter connected between an input terminal and an output terminal; a first inductor connected between the coupled multi-mode acoustic wave filter and a ground terminal; an acoustic wave resonator, one end of which is connected between the input terminal or the output terminal and the coupled multi-mode acoustic wave filter; and a second inductor connected between another end of the acoustic wave resonator and the ground terminal.

Abstract: An acoustic wave filter device includes plural filter circuits between an input terminal and an output terminal. Plural inductors are connected in series in a series arm that connects the input terminal and the output terminal, and plural first acoustic wave resonators are connected between the series arm and a ground potential. Each of the filter circuits includes at least one of the inductors and one of the first acoustic wave resonators. A second acoustic wave resonator in the series arm connects adjacent filter circuits. The acoustic wave filter device has a pass band lower than a trap band, steep attenuation characteristics in a range from the pass band to the trap band, and is capable of providing a large amount of attenuation in the trap band.

Abstract: A duplexer includes a transmission filter and a reception filter having different passbands, wherein: first resonators that are series resonators or parallel resonators included in the transmission and reception filters so as to form a skirt characteristic at a guard band side are a temperature compensated type piezoelectric thin film resonator or a surface acoustic wave resonator using Love waves, and second resonators that form a skirt characteristic at an opposite side to the guard band are one of a temperature non-compensated type piezoelectric thin film resonator, a surface acoustic wave resonator using a lithium tantalate substrate or a substrate made by bonding a lithium tantalate substrate on a sapphire substrate, and a surface acoustic wave resonator using Love waves.

Abstract: A filter includes: first series resonators and first parallel resonators that are connected in a ladder shape between an input terminal and an output terminal; a first inductor that is connected in parallel to at least one first series resonator; one or more second parallel resonators that are provided separately from the first parallel resonators, are connected between the input terminal and the output terminal, and have a resonance frequency and an anti-resonance frequency at frequencies lower than a passband formed by the first series resonators and the first parallel resonators; wherein an attenuation region is formed by a first attenuation pole formed by the at least one first series resonator and the first inductor and a second attenuation pole formed by a resonant response of the one or more second parallel resonators.

Abstract: A duplexer includes: a transmit filter that is connected between an antenna terminal and a transmit terminal and has a plurality of acoustic wave resonators; a receive filter that is connected between the antenna terminal and a receive terminal and has a plurality of acoustic wave resonators; and a delay line or a longitudinal coupling type resonator that is connected in parallel with at least one of the plurality of acoustic wave resonators of the transmit filter and the plurality of acoustic wave resonators of the receive filter and has at least two IDTs (Interdigital Transducers).

Abstract: An antenna duplexer includes a transmission filter and a reception filter both coupled with an antenna terminal. A pass band of the transmission filter is lower than a pass band of the reception filter. The transmission filter includes a first series resonator coupled with a first terminal, a second series resonator connected to the first series resonator at a first node, a first parallel resonator connected to a first port of the first series resonator, a second parallel resonator connected to a first node and the first parallel resonator at a second node, a third parallel resonator connected to the first node, a fourth parallel resonator connected to the third parallel resonator at a third node, a first inductance element coupled with the second node and a ground, and a second inductance element coupled with the third node and the ground. The first and second parallel resonators and the first inductance element produce an attenuation pole at a frequency lower than a pass band of the transmission filter.

Abstract: Carbon nanofiber resonator devices, methods for use, and applications of said devices are disclosed. Carbon nanofiber resonator devices can be utilized in or as high Q resonators. Resonant frequency of these devices is a function of configuration of various conducting components within these devices. Such devices can find use, for example, in filtering and chemical detection.

Abstract: A small-sized surface acoustic wave filter device having favorable filter characteristics includes a transmission-side surface acoustic wave filter chip including a ladder surface acoustic wave filter unit located on a piezoelectric substrate. The ladder surface acoustic wave filter unit includes a series arm connected between an input pad and an output pad and a plurality of resonators and including at least one first resonator connected to the input pad or the output pad. A die-attach surface is provided with an inductor connected to the first resonator. The inductor is arranged such that at least a portion thereof faces the first resonator and does not face any of the plurality of resonators and other than the first resonator.

Abstract: On a piezoelectric board, a SAW element has first to fifth IDT electrodes and reflector electrodes with first to fourth electrode-finger narrow-pitch portions N1-N4 being formed in the respective ones of adjoining portions of the respective first to fifth IDT electrodes. An unbalanced signal terminal and balanced signal terminals are connected to the SAW element. The electrode finger pitches of the first to fourth electrode-finger narrow-pitch portions N1-N4 are formed symmetrically with respect to the third, central IDT electrode in such a manner that the electrode finger pitch of the first electrode-finger narrow-pitch portion N1 is narrower than that of the second electrode-finger narrow-pitch portion N2, while the electrode finger pitch of the fourth electrode-finger narrow-pitch portion N4 is narrower than that of the third electrode-finger narrow-pitch portion N3.

Abstract: An acoustic wave device includes: a multilayer structure that has plural surfaces which principal surfaces of plural layers provide; a chip including an acoustic wave filter and mounted on a first surface; a resin unit sealing the chip; a wiring pattern that is formed on a second surface and electrically connected to at least one of resonators; a ground pattern that is formed on the second surface along a part of the wiring pattern, and is away from the wiring pattern; and an external terminal that is formed on a third surface and electrically connected to the wiring pattern and the ground pattern, the third surface being disposed on an opposite side of the first surface with respect to the second surface; wherein a part of the wiring pattern that comes closest to the ground pattern is substantially formed in parallel with the ground pattern.

Abstract: A power device comprises an output port and at least one first acoustic pathway and one second acoustic pathway, each acoustic pathway comprising at least one first input acoustic wave transducer connected to an input port, and an output acoustic wave transducer connected to the output port. Each acoustic pathway further comprises a floating acoustic wave transducer connected to a floating port; the input transducer and the output transducer being separated by a distance equal to (2m+1)?/4 with m an integer and ? the propagation wavelength; the input transducer and the floating transducer being separated by a distance equal to (2n+1) ?/2 with n an integer; each output transducer being connected to the output port, said power device being a combiner.

Abstract: The present invention is an acoustic wave device including first and second acoustic wave resonators. A first tilt angle that is an angle formed between a direction perpendicular to a direction in which electrode fingers of the first acoustic wave resonator extend and a direction along which the electrode fingers are arranged is different from a second tilt angle that is an angle formed between a direction perpendicular to a direction in which electrode fingers of the second acoustic wave resonator extend and a direction along which the electrode fingers are arranged.

Abstract: An SAW device includes: a piezoelectric substrate 1; a first and a second SAW elements 2, 3 having three or more odd-number IDT electrodes 4-9 and reflector electrodes 10-13 arranged on the piezoelectric substrate 1; lines 16 which cascade-connect the first and the second SAW elements 2, 3; a first unbalanced signal terminal 14 connected to the IDT electrodes 4, 6 arranged at the both ends of the first SAW elements 2; and a second unbalanced signal terminal 15 connected to the IDT electrodes 7, 9 arranged at the both ends of the second SAW element 3. In each of the first and the second SAW elements 2, 3, one bus bar electrode 17 of each of center IDT electrodes 5, 8 is split into two, and non-split bus bar electrodes 18, 19 of at least one center IDT electrode of the first and the second SAW elements 2, 3 are connected to a reference potential electrode and the lines 16 are made to be balanced signal lines.

Abstract: A filtering device comprises an analogue quadrature splitter together with a first filtering element and a second filtering element. The filtering device is adapted to transform filtering characteristics of the first filtering element and filtering characteristics of the second filtering element into an effective filtering characteristic present in an output signal at an output terminal of the analogue quadrature splitter. The first filtering element and the second filtering element comprise filtering elements of high accuracy, with a steep roll-off but poor power handling capabilities. Using a high power quadrature splitter it is possible to transform the filtering characteristics of the first filtering element and/or the second filtering characteristic of the second filtering element into the effective filtering characteristics.

Abstract: To provide a receiving side filter of a duplexer and a duplexer capable of preventing a leakage of an electric field and a magnetic field to the outside. In a receiving side filter having a longitudinal mode resonator type filter including cross finger electrodes and reflectors respectively formed on a piezoelectric substrate and an unbalanced input signal path and balanced output ports respectively provided on an input side and on an output side of the longitudinal mode resonator type filter, and used on a receiving side of a duplexer, a shield electrode connected to a ground electrode side of the cross finger electrode is disposed to surround a periphery of the receiving side filter so that an electric field and a magnetic field leaked to the outside from the receiving side filter are short-circuited by the shield electrode.

Abstract: A ladder acoustic wave filter device is constructed such that ripples in the pass band are suppressed, and insertion loss is small in both of a high frequency side portion and a low frequency side portion of the pass band. Apodization weighting is applied to a series-arm-side IDT electrode. Busbars of the series-arm-side IDT electrode are configured so that in an acoustic wave propagation direction, a distance in an overlap width direction between the busbars becomes shorter as the overlap width of electrode fingers becomes smaller. Each of a pair of comb-shaped electrodes of a parallel-arm-side IDT electrode further includes a plurality of dummy electrodes that extend from a busbar and are opposed to electrode fingers of the other comb-shaped electrode in the overlap width direction. The parallel-arm-side IDT electrode is a normal IDT electrode in which the overlap width is constant.

Abstract: A branching filter includes a longitudinally-coupled-resonator-type elastic wave filter having a balanced-unbalanced transformation function and the branching filter has excellent balance characteristics and a small size. The branching filter includes a ladder elastic wave filter chip and a longitudinally-coupled-resonator-type elastic wave filter chip. An antenna back-surface electrode and an antenna electrode pad are connected to each other via a first wiring provided in a wiring substrate. The antenna electrode pad and a longitudinally-coupled-resonator-type elastic wave filter are connected to each other via a second wiring provided on a piezoelectric substrate. The second wiring extends in a first direction and a first functional electrode and a second functional electrode provided on the piezoelectric substrate are axisymmetrically arranged with respect to each other about a central axis that extends in the first direction of the second wiring.

Abstract: The present invention relates to a component (BE) which has a first duplexer operating with acoustic waves and a second duplexer operating with acoustic waves, wherein the first and second duplexers are arranged in a single SMD housing. In addition, the invention relates to a module (MO), which interconnects such a component (BE) and at least three 90° hybrids (HYB1-HYB3) to form an enhanced duplexer. A further aspect of the invention relates to a 2in1 hybrid, in which two 90° hybrids (HYB3, HYB4) or one 90° hybrid (HYB3) and one 180° hybrid (BAL) are arranged on a single chip.

Abstract: A SAW filter includes a piezoelectric body, an IDT electrode on the piezoelectric body, and signal wiring electrically connected to the IDT electrode. The signal wiring has a thickness not less than a skin depth specified based on the frequency of a signal passing through the signal wiring and the electrical conductivity of the signal wiring. As a result, the signal wiring has low propagation loss of the signal passing through it, so that the SAW filter has excellent transmission characteristics.

Abstract: An elastic wave filter device includes first and second inductance elements included in a laminated substrate and first and second elastic wave filter chips mounted on the laminated substrate by flip-chip bonding. The first and second inductance elements provided in the laminated substrate include first and second coil patterns, respectively, which are provided in a plane located at a certain height level in the laminated substrate. The second coil pattern is arranged in a region in which the first coil pattern is provided.

Abstract: In accordance with a representative embodiment, a BAW resonator structure, comprises a first BAW resonator, comprising: a first lower electrode having a first electrical resistance; a first upper electrode having a second electrical resistance; and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode. The BAW resonator structure also comprises a second BAW resonator, comprising: a second lower electrode having the second electrical resistance; a second upper electrode having the first electrical resistance; and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises an acoustic coupling layer disposed between the first BAW resonator and the second BAW resonator. The first electrical resistance is less than the second electrical resistance. An communication device comprising a coupled resonator filter (CRF) is also disclosed.

Abstract: A communication module includes a plurality of duplexers, wherein at least either IDT electrodes of transmit filters of at least two of the plurality of duplexers having a different transmit band or IDT electrodes of receive filters of at least two of the plurality of duplexers having a different receive band are composed of a same material, have a same thickness and are provided on a single piezoelectric substrate.

Abstract: An acoustic wave duplexer includes a piezoelectric substrate, a first filter and a second filter whose center frequency is higher than that of the first filter, the first and second filters being provided on the piezoelectric substrate. The first filter is structured as a ladder type. A resonator positioned nearest to an antenna terminal out of series-arm resonators is designated as a first resonator. A pitch of a comb-shaped electrode structuring the first resonator is set such that a bulk wave emission frequency of the first resonator becomes higher than a passband of the second filter.

Abstract: A duplexer includes first and second filters, and a first shielding bondwire. The first filter includes a first bondwire connecting the first filter to a printed circuit board, the first bondwire forming a portion of a first virtual loop having a first virtual area, where first current passing through the first bondwire generates a first magnetic field. The second filter includes a second bondwire connecting the second filter to the printed circuit, the second bondwire forming a portion of a second virtual loop having a second virtual area. The first shielding bondwire includes first and second ends connected to a conductor of the printed circuit board to form a closed electrical first shielding loop having a corresponding first shielding area. The magnetic field induces shielding current in the first shielding loop, which generates a first compensating magnetic field that attenuates the first magnetic field.

Abstract: Provided are improvements to photo detecting devices and methods for enhancing the sensitivity of photo detecting devices. A photo detecting device generates an electronic signal in response to a received light pulse. An electro-mechanical acoustic resonator, electrically coupled to the photo detecting device, damps the electronic signal and increases the signal noise ratio (SNR) of the electronic signal. Increased photo detector standoff distances and sensitivities will result.

Abstract: A duplexer includes an unbalanced transmitting filter; a balanced receiving filter; a transmitting port connected to the transmitting filter; and a first receiving port and a second receiving port connected to the receiving filter. The duplexer also includes an electromagnetic coupling portion connected between the transmitting port and the first receiving port and between the transmitting port and the second receiving port. The electromagnetic coupling portion adjusts the phase between electric power that flows from the transmitting port to the first receiving port and electric power that flows from the transmitting port to the second receiving port.

Abstract: A circuit module includes a duplexer and a circuit substrate. A first signal path connects a first external electrode to a second external electrode. A second signal path connects a third external electrode to a fourth external electrode. A third signal path connects a fifth external electrode to a sixth external electrode. A first ground path connects a seventh external electrode to an eighth external electrode. A second ground path is connected to a ninth external electrode and is capacitively coupled to the second signal path.

Abstract: An acoustic wave device includes: a substrate; a lower electrode formed on the substrate; at least two piezoelectric films formed on the lower electrode; an insulating film located between the at least two piezoelectric films; and an upper electrode formed on the at least two piezoelectric films, wherein an outer periphery of an uppermost piezoelectric film out of the at least two piezoelectric films in a region in which the lower electrode and the upper electrode face each other is positioned further in than an outer periphery of the upper electrode.

Abstract: An acoustic wave filter including piezoelectric thin film resonators, in which at least two of the piezoelectric thin film resonators including: a substrate; a piezoelectric film located on the substrate; a lower electrode and an upper electrode located across at least a part of the piezoelectric film; a mass load film for a frequency control located in a resonance region where the lower electrode and the upper electrode face each other, and having a shape different from that of the resonance region; and a temperature compensation film having a temperature coefficient of an elastic constant opposite in sign to that of the piezoelectric film, at least a part of the temperature compensation film being located between the lower electrode and the upper electrode in the resonance region, and areas of mass load films of said at least two of the piezoelectric thin film resonators are different from each other.

Abstract: A duplexer includes an acoustic wave element having a first terminal and a second terminal; a substrate; a first columnar conductor electrically connected to the first terminal, and drawn to a back surface of the substrate while partially in the substrate; a second columnar conductor electrically connected to the second terminal, and drawn to the back surface of the substrate while partially in the substrate. Additionally, a first ground pattern region is between the first columnar conductor drawn part and the second columnar conductor drawn part on the back surface of the substrate; a second ground pattern region is electrically connected to the first ground pattern region and arranged in the part not including the part between the first columnar conductor drawn part and the second columnar conductor drawn part; and a third columnar conductor electrically is connected to the first ground pattern region while partially in the substrate.

Abstract: A bulk acoustic wave resonator (BAWR) includes a bulk acoustic resonance unit and at least one compensation layer. The bulk acoustic resonance unit includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode. The first electrode, the second electrode, and the piezoelectric layer each include a material that modifies a resonance frequency based on a temperature, and the at least one compensation layer includes a material that adjusts the resonance frequency modified based on the temperature in a direction opposite to a direction of the modification.

Abstract: A branching filter includes an antenna terminal, a transmission signal terminal, a reception signal terminal, a transmission filter element, and a reception filter element. At least one of the transmission filter element and the reception filter element includes a longitudinally coupled resonator filter element having first and second IDT electrodes arranged along a direction of propagation of an elastic wave. The first IDT electrode includes a first end connected to the antenna terminal. The second IDT electrode includes a first end connected to one of the transmission signal terminal and the reception signal terminal. The longitudinally coupled resonator filter element further includes an inductor connected in series between a second end of the first IDT electrode and a ground potential.

Abstract: Disclosed is a miniaturized duplexer having a good isolation characteristic. A duplexer having a high band side filter and a low band side filter that are each formed in a ladder-type filter provided on a common piezoelectric substrate is provided with a first elastic wave resonator to be included in one of these filters, a second elastic wave resonator to be included in the other of the filters, and a first additional grating reflector provided between these resonators to reflect an elastic wave leaked from a grating reflector of the first elastic wave resonator, and in which an additional grating reflector is not provided on a side opposite to the second elastic wave resonator in the first elastic wave resonator.

Abstract: In a high frequency device, resonators (IDT capacitors) that function as capacitors are included in a lumped constant balun included in a filter or duplexer, and furthermore, the resonance frequency of the IDT capacitors is set higher than the passband frequency of the filter. This improves the capacitor Q value, thus enabling the realization of a low-loss balance filter.

Abstract: A ladder filter including a series arm resonator and a parallel arm resonator disposed on the same common piezoelectric substrate achieves improved miniaturization. The ladder filter includes series arm resonators and parallel arm resonators, which include elastic wave resonators, and are disposed on the same common piezoelectric substrate, at least one parallel arm resonator of the series arm resonators and the parallel arm resonators includes a first resonator and a second resonator electrically connected in parallel to each other, and the first resonator and the second resonator are arranged in parallel or substantially in parallel in a direction perpendicular or substantially perpendicular to an elastic wave propagation direction, on one side outside one series arm resonator of remaining resonators in the elastic wave propagation direction thereof.

Abstract: An acoustic wave device includes an input terminal; a balun that is connected to the input terminal, converts a signal input from the input terminal into two anti-phase signals, and outputs the two anti-phase signals; and a filter that is connected to the balun, and outputs the two anti-phase signals input from the balun as balanced output signals. An output impedance of the balun is equal to an input impedance of the filter, and is larger than an output impedance of the filter.

Abstract: A duplexer includes an acoustic wave element having a first terminal and a second terminal; a substrate; a first columnar conductor electrically connected to the first terminal, and drawn to a back surface of the substrate while partially in the substrate; a second columnar conductor electrically connected to the second terminal, and drawn to the back surface of the substrate while partially in the substrate. Additionally, a first ground pattern region is between the first columnar conductor drawn part and the second columnar conductor drawn part on the back surface of the substrate; a second ground pattern region is electrically connected to the first ground pattern region and arranged in the part not including the part between the first columnar conductor drawn part and the second columnar conductor drawn part; and a third columnar conductor electrically is connected to the first ground pattern region while partially in the substrate.

Abstract: A duplexer formed on a piezoelectric substrate includes a low band side filter and a high band side filter, and has an improved isolation characteristic in a pass frequency band of the high band side filter. Transmission and reception of signals are respectively performed from either of the low band side filter and the high band side filter and the other filter with respect to an input/output port. Series arms and parallel arms each formed of an elastic wave resonator form the low band side filter. A shield electrode is disposed close to either of the input/output port and a low band side filter port, and is grounded for capacitive coupling with same.

Abstract: The present disclosure provides a duplexer for separating a transmit signal and a receive signal. The duplexer comprises a transmit filter, a receive filter and an analogue quadrature splitter, a first filtering element and a second filtering element. By choosing the first filtering element and the second filtering element substantially identical, it is possible to transform filtering characteristics of the first and second filtering element such that stop bands are substantially transformed into an effective pass band, and vice versa. The analogue quadrature splitter is adapted to increase an attenuation of the transmit signals outside the transmit band, such as in the receive band. Therefore out-of-band emissions by the transmitter will be substantially reduced. The present disclosure further provides a method for separating a transmit signal and a receive signal, and computer program products for the manufacture for carrying out the method of separating transmit signals and receive signals.

Abstract: Provided are a first filter 63a and a second filter 63b each having a pass band in the range of a frequency band that is obtained by, for example, substantially bisecting a frequency band of f1 to f4. In that case, the regions of the first filter 63a and the second filter 63b partially overlap with each other with the center frequency f5 interposed therebetween. In practice, even if the division is not bisection, a configuration is adopted in which a frequency region of the wider band (the first frequency band 61a) closer to a second frequency band 61b side is covered by the second filter 63b. Accordingly, it is possible to suppress the influence of load fluctuation in a multiband-compatible radio communication device.