Abstract: A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 ?mRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.

Abstract: A duplexer (1) comprises a chip (10) including a transmission filter (97) for passing a transmission signal therethrough and interrupting a reception signal and a reception filter (98) for passing a reception signal therethrough and interrupting a transmission signal. Each of the transmission filter (97) and the reception filter (98) includes thin-film piezoelectric resonators (16 and 17) each of which has a piezoelectric thin film that exhibits a piezoelectric property and two excitation electrodes that are disposed on both surfaces of the piezoelectric thin film and apply an excitation voltage to the piezoelectric thin film. All of the thin-film piezoelectric resonators (16 and 17) that the transmission filter (97) and the reception filter (98) include are disposed on a single base.

Abstract: A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23. are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 ?mRMS Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.

Abstract: A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23 are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 ?mRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.

Abstract: A thin-film piezoelectric resonator including a piezoelectric thin film having piezoelectric characteristic, and an upper electrode and a lower electrode arranged on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film, wherein: each of the upper electrode and the lower electrode includes a resonant portion, and a lead-out portion; and the electrode thickness of at least one part of the lead-out portion in at least one of the upper electrode and the lower electrode is larger than the electrode thickness of the resonant portion formed to be continued from the lead-out portion.

Abstract: A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23 are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 &mgr;mRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.

Abstract: A duplexer (1) comprises a chip (10) including a transmission filter (97) for passing a transmission signal therethrough and interrupting a reception signal and a reception filter (98) for passing a reception signal therethrough and interrupting a transmission signal. Each of the transmission filter (97) and the reception filter (98) includes thin-film piezoelectric resonators (16 and 17) each of which has a piezoelectric thin film that exhibits a piezoelectric property and two excitation electrodes that are disposed on both surfaces of the piezoelectric thin film and apply an excitation voltage to the piezoelectric thin film. All of the thin-film piezoelectric resonators (16 and 17) that the transmission filter (97) and the reception filter (98) include are disposed on a single base.

Abstract: A piezoelectric resonant filter comprises a chip having a plurality of thin-film piezoelectric resonators, and a mounting substrate on which the chip is mounted. The chip is mounted on the mounting substrate by flip chip bonding. A plurality of bumps provided on the chip are bonded to a plurality of conductors on the mounting substrate by interdiffusion between atoms, in a solid phase, of the respective metals of which the bumps and the conductors are made, without involving melting of the respective metals of which the bumps and the conductors are made. The chip has a series resonator and a parallel resonator each formed of a thin-film piezoelectric resonator. These resonators constitute a ladder filter circuit.

Abstract: A thin-film piezoelectric resonator including a piezoelectric thin film having piezoelectric characteristic, and an upper electrode and a lower electrode arranged on opposite surfaces of the piezoelectric thin film for applying an excitation voltage to the piezoelectric thin film, wherein: each of the upper electrode and the lower electrode includes a resonant portion, and a lead-out portion; and the electrode thickness of at least one part of the lead-out portion in at least one of the upper electrode and the lower electrode is larger than the electrode thickness of the resonant portion formed to be continued from the lead-out portion.

Abstract: A basic portion layer 21 of a substrate electrode 12a connected to a projecting electrode 13 electrically and mechanically on a substrate member of ceramics. The substrate member on which the basic portion layer 21 is formed is subjected to sintering. A surface of the basic portion layer 21 in the sintered substrate member is polished. On the polished basic portion layer 21, the plating layers 22, 23, are formed, so that surface roughness of the substrate electrode 12a may be, for example, not larger than 0.1 &mgr;mRMS. Accordingly, junction strength of an integrated circuit element mounted on a packaging substrate by a flip-chip method can be improved.

Abstract: A piezoelectric resonant filter comprises a chip having a plurality of thin-film piezoelectric resonators, and a mounting substrate on which the chip is mounted. The chip is mounted on the mounting substrate by flip chip bonding. A plurality of bumps provided on the chip are bonded to a plurality of conductors on the mounting substrate by interdiffusion between atoms, in a solid phase, of the respective metals of which the bumps and the conductors are made, without involving melting of the respective metals of which the bumps and the conductors are made. The chip has a series resonator and a parallel resonator each formed of a thin-film piezoelectric resonator. These resonators constitute a ladder filter circuit.

Abstract: In a mobile communication device, a power amplifier amplifies the power of a signal to be transmitted. A transmitter filter limits the frequency band of the amplified signal to a predetermined frequency band for transmission. The signal limited in frequency band is transmitted via an antenna. Output power control circuitry controls the output power of the signal to be transmitted and has an output power sensor and an automatic power control circuit. The output power sensor succeeds the transmitter filter in the direction of flow of the signal to be transmitted, and senses the output power of the signal. The automatic power control circuit controls the gain of the power amplifier such that the output power sensed by the output power sensor coincides with a preselected reference value.

Abstract: A stripline resonator is constructed of a dielectric plate having a ground electrode formed on a side surface thereof, an open-ended .lambda./2 long stripline arranged on a top surface of the dielectric plate, an input terminal to which signals are inputted, said input terminal is connected to one end of the open-ended .lambda./2 long stripline, a first reactance element connected either in series or in parallel between the input terminal and the open-ended .lambda./2 long stripline, and a second reactance element connected at one end thereof to an opposite end of the open-ended .lambda./2 long stripline and at an opposite end to a ground electrode.

Abstract: An LC-type dielectric filter includes a plurality of substrate layers which are arranged in a stack and laminated to form a multi-layer substrate. Strip line resonators are provided on some of the substrate layers. The filter has a plurality of terminals, which are connected to resonators. The terminals are also capacitively or inductively coupled to each other. At least one grounding layer is included in the stack for electrically isolating the resonators. Coupling between the resonators can be obtained by forming a plurality of resonators close to one another on the same substrate layer. Further, a duplexer can be made from filters of this type. The duplexer may include a matching circuit and a power amplifier for RF transmission.

Abstract: A compact, high performance strip line filter which may be made thinner than a dielectric filter having comparable performance characteristics. The strip line filter includes a rectangular box-shaped, dielectric block having parallel grooves, formed in a front face with a predetermined spacing therebetween, the grooves extending from a top face to a bottom face of the block. A thin film outer conductive layer covers the side faces, the back face, and the bottom face. Resonator conductors, each formed of a thin film of conductive material, cover the respective surfaces of the grooves and are connected to the outer conductor. According to a further aspect, a substrate, with capacitor formed thereon, opposes a face of the dielectric block to provide capacitive coupling. The capacitors may be arranged to provide attenuation poles at finite frequencies. In accordance with another aspect, such strip line filters are used as the transmitting and receiving filters of a duplexer filter.

Abstract: A branching filter in which an input/output port, a first dielectric filter for use in transmission and a second dielectric filter for use in reception are coupled with each other through a branching filter circuit. The branching filter circuit includes a first line provided between the input/output port and an input port of the second dielectric filter, a second line provided between the input/output port and an output port of the first dielectric filter, and a third line provided between the input/output port and the ground. In the filter, conductor lines for use in connection between ports are used for the first and second lines.

Abstract: A dielectric filter includes a unitary dielectric block formed of a uniform, single dielectric material and having electrically conductive metallized patterns formed on front, rear and lateral walls, and on an outer bottom surface thereof. A plurality of coaxial dielectric resonators each including an open end and a central conductor are longitudinally arranged along the center of a top surface of the block and are spaced apart a predetermined distance. Frequency adjusting patterns are formed on the top surface of the block, each frequency adjusting pattern extending around an open end of a respective one of the resonators. Coupling amount adjusting patterns are also disposed on the top surface of the block, each connected to the front and rear walls and disposed between adjacent ones of the frequency adjusting patterns. At least one additional coupling amount adjusting pattern is disposed on the top surface of the block.

Abstract: A dielectric filter includes a homogeneous monolithic block of dielectric material having a plurality of parallel extending dielectric resonators formed therein. A plurality of first electrodes extend alond the top surface of the monolithic block, each encompassing an opening in the monolithic block defined by a corresponding one of the plurality of dielectric resonators. Either the distance between adjacent dielectric resonators or the configuration of the first electrodes is established to cause an overcoupling based on the coupling impedance, thereby tuning an attenuation pole of the dielectric filter to a finite frequency. Additionally, second electrodes are provided along the top surface of the monolithic block extending between and spaced from the first electrodes and connected to a ground electrode.

Abstract: An LC-type dielectric filter which includes strip lines on a dielectric plate forming distributed constant type resonators. The strip lines and other elements of the filter, such as coupling capacitances are plated onto the dielectric plate as printed circuits to realize a small, high-Q dielectric filter which is suitable for mass-production.

Abstract: A microstrip line type resonator includes a rectangular parallelapiped dielectric plate, and a conductive microstrip line disposed on a top surface of the dielectric plate. The microstrip line has opposite ends respectively spaced from front and rear edges of the dielectric plate. The resonator further includes a first grounding layer disposed on an entirety of the bottom surface of the dielectric plate, and a second grounding layer disposed an entirety of the front, rear and side surfaces of the dielectric plate. The first grounding layer is electrically connected to the second grounding layer at the edges of the bottom surface of the dielectric plate. The microstrip line type resonator is a 1/2 wavelength resonator.