Abstract: A radio-frequency circuit module includes a multilayer body and a surface-mount component mounted on a front surface of the multilayer body. The surface-mount component includes variable capacitance elements integrated therein. Inductors including conductor patterns are provided in the multilayer body. On a back surface of the multilayer body, a first external connection terminal and a second external connection terminal are sandwiched between ground connection terminals. Ground via-conductors connected to ground connection terminals extend to the front surface of the multilayer body. The ground via-conductors are connected to each other in a layer near the front surface by a ground connection conductor which extends in a direction perpendicular or substantially perpendicular to the extending direction.

Abstract: A high frequency circuit module includes a variable inductance circuit portion and a reactance circuit portion. The variable inductance circuit portion is connected between an antenna port and ground. The variable reactance circuit is connected between the antenna port and a front-end port. The variable inductance circuit portion includes a first inductor, a second inductor, and a switch. The first inductor is connected between the antenna port and the ground. The second inductor and the switch are connected in series, and this series circuit is connected in parallel to the first inductor.

Abstract: A radio-frequency circuit module includes a multilayer body and a surface-mount component mounted on a front surface of the multilayer body. The surface-mount component includes variable capacitance elements integrated therein. Inductors including conductor patterns are provided in the multilayer body. On a back surface of the multilayer body, a first external connection terminal and a second external connection terminal are sandwiched between ground connection terminals. Ground via-conductors connected to ground connection terminals extend to the front surface of the multilayer body. The ground via-conductors are connected to each other in a layer near the front surface by a ground connection conductor which extends in a direction perpendicular or substantially perpendicular to the extending direction.

Abstract: A high frequency circuit module includes a variable inductance circuit portion and a reactance circuit portion. The variable inductance circuit portion is connected between an antenna port and ground. The variable reactance circuit is connected between the antenna port and a front-end port. The variable inductance circuit portion includes a first inductor, a second inductor, and a switch. The first inductor is connected between the antenna port and the ground. The second inductor and the switch are connected in series, and this series circuit is connected in parallel to the first inductor.

Abstract: In a variable capacitance module capable of achieving necessary variable capacitance ranges, a variable capacitance circuit includes a variable capacitance element and fixed capacitance elements. A first variable capacitance element and a first fixed capacitance element are connected in series, and the series circuit thereof and a second fixed capacitance element are connected in parallel. Accordingly, with reference to the capacitance of the second fixed capacitance element, the range of the combined capacitance of the variable capacitance circuit is provided by a step size of capacitance based on the combined capacitance of the variable capacitance element and the first fixed capacitance element. The first and second fixed capacitance elements are defined by inner-layer flat-plate electrodes in a laminated substrate, and the variable capacitance element is defined by an MEMS element mounted on a top surface of the laminated substrate.

Abstract: In a variable capacitance module capable of achieving necessary variable capacitance ranges, a variable capacitance circuit includes a variable capacitance element and fixed capacitance elements. A first variable capacitance element and a first fixed capacitance element are connected in series, and the series circuit thereof and a second fixed capacitance element are connected in parallel. Accordingly, with reference to the capacitance of the second fixed capacitance element, the range of the combined capacitance of the variable capacitance circuit is provided by a step size of capacitance based on the combined capacitance of the variable capacitance element and the first fixed capacitance element. The first and second fixed capacitance elements are defined by inner-layer flat-plate electrodes in a laminated substrate, and the variable capacitance element is defined by an MEMS element mounted on a top surface of the laminated substrate.

Abstract: A series resonance circuit defined by a series circuit including an inductor and a capacitor and a series resonance circuit defined by a series circuit including an inductor and a capacitor are connected in shunt to a signal line. A diode is disposed between the grounding end of the series resonance circuit and the ground, and a diode is disposed between the grounding end of the series resonance circuit and the ground. The connection point between the grounding end of the series resonance circuit and the diode is connected to the ground via a frequency shifting inductor in a conductive state at high frequency, and the connection point between the grounding end of the series resonance circuit and the diode is connected to the ground via a frequency shifting inductor in a conductive state at high frequency. A matching circuit defined by a multistage T-shape LCL circuit is disposed between the series resonance circuits.

Abstract: A high-frequency composite component for selectively switching a GSM-system signal path and a DCS-system signal path for a signal transmitted to or received from an antenna terminal by a diplexer. Transmission-side input terminals and reception-side balanced output terminals to be switched by high-frequency switches are included in the GSM and the DCS systems. Matching elements include inductors and capacitors that are inserted between the reception-side balanced output terminals and the output side of surface acoustic wave filters.

Abstract: A series resonance circuit defined by a series circuit including an inductor and a capacitor and a series resonance circuit defined by a series circuit including an inductor and a capacitor are connected in shunt to a signal line. A diode is disposed between the grounding end of the series resonance circuit and the ground, and a diode is disposed between the grounding end of the series resonance circuit and the ground. The connection point between the grounding end of the series resonance circuit and the diode is connected to the ground via a frequency shifting inductor in a conductive state at high frequency, and the connection point between the grounding end of the series resonance circuit and the diode is connected to the ground via a frequency shifting inductor in a conductive state at high frequency. A matching circuit defined by a multistage T-shape LCL circuit is disposed between the series resonance circuits.

Abstract: In a filter module, a common input/output portion of a switch circuit is set as a first port. A first filter arranged to pass a signal in a first frequency band is connected between a first input/output portion of the switch circuit and a second port. A second filter arranged to pass a signal in a second frequency band is connected between a second input/output portion and the second port. A phase adjusting circuit is provided such that an impedance in the second frequency band as seen from the first port while the switch circuit selects the first input/output portion is in a substantially short-circuited state. This arrangement prevents leakage of unwanted signals from a signal path used in a communication system not in operation among two communication systems for different frequency bands while the other communication system is engaged in communication.

Abstract: A high frequency front-end module includes an antenna terminal ANT, a diplexer, high frequency switches, LC filters, and SAW duplexers. The SAW duplexer is defined by SAW filters and high-pass filters disposed at input sides thereof. The high-pass filters function as phase-matching elements having an anti-surge function against a surge coming from the antenna terminal ANT.

Abstract: A balanced/unbalanced filter module includes a switch including a first port that inputs and outputs unbalanced signals in a first frequency band, a second port that inputs and outputs unbalanced signals in a second frequency band, and a third port that inputs and outputs unbalanced signals in these two frequency bands. The switch switches a signal path. An unbalanced I/O port of a first filter that passes signals in the first frequency band is connected to the port. A port of a second filter that passes signals in the second frequency band is connected to the port. Individual balanced I/O ports of each of the first and second filters are connected to first and second branch ports with substantially the same electrical length. A balance coil for impedance matching is provided between the first and second branch ports.

Abstract: In a filter module, a common input/output portion of a switch circuit is set as a first port. A first filter arranged to pass a signal in a first frequency band is connected between a first input/output portion of the switch circuit and a second port. A second filter arranged to pass a signal in a second frequency band is connected between a second input/output portion and the second port. A phase adjusting circuit is provided such that an impedance in the second frequency band as seen from the first port while the switch circuit selects the first input/output portion is in a substantially short-circuited state. This arrangement prevents leakage of unwanted signals from a signal path used in a communication system not in operation among two communication systems for different frequency bands while the other communication system is engaged in communication.

Abstract: A high-frequency composite component for selectively switching a GSM-system signal path and a DCS-system signal path for a signal transmitted to or received from an antenna terminal by a diplexer. Transmission-side input terminals and reception-side balanced output terminals to be switched by high-frequency switches are included in the GSM and the DCS systems. Matching elements include inductors and capacitors that are inserted between the reception-side balanced output terminals and the output side of surface acoustic wave filters.

Abstract: A high frequency front-end module includes an antenna terminal ANT, a diplexer, high frequency switches, LC filters, and SAW duplexers. The SAW duplexer is defined by SAW filters and high-pass filters disposed at input sides thereof. The high-pass filters function as phase-matching elements having an anti-surge function against a surge coming from the antenna terminal ANT.

Abstract: A high-frequency module includes a diplexer, first and second high-frequency switches, a SAW duplexer, first and second LC filters functioning as first and second filters, and an SAW filter functioning as a third filter, the module defines a unit that integrates front-end sections of first to third communication systems, a digital cellular system (1.8 GHz band), a personal communication service (1.9 GHz band) and a global system for mobile communications (900 MHz band).

Abstract: A high-frequency composite component for selectively switching a GSM-system signal path and a DCS-system signal path for a signal transmitted to or received from an antenna terminal by a diplexer. Transmission-side input terminals and reception-side balanced output terminals to be switched by high-frequency switches are included in the GSM and the DCS systems. Matching elements include inductors and capacitors that are inserted between the reception-side balanced output terminals and the output side of surface acoustic wave filters.

Abstract: A balanced/unbalanced filter module includes a switch including a first port that inputs and outputs unbalanced signals in a first frequency band, a second port that inputs and outputs unbalanced signals in a second frequency band, and a third port that inputs and outputs unbalanced signals in these two frequency bands. The switch switches a signal path. An unbalanced I/O port of a first filter that passes signals in the first frequency band is connected to the port. A port of a second filter that passes signals in the second frequency band is connected to the port. Individual balanced I/O ports of each of the first and second filters are connected to first and second branch ports with substantially the same electrical length. A balance coil for impedance matching is provided between the first and second branch ports.

Abstract: A high-frequency module includes a switching circuit having a phase-shift circuit. The phase-shift circuit matches only PCS/DCS reception signals so as to be passed therethrough by setting a control-voltage input terminal to a Low level when receiving PCS/DCS signals, and attenuates PCS/DCS transmission signals to the PCS/DCS reception circuit side by setting the control-voltage input terminal to a Hi level when transmitting PCS/DCS signals. Also, another phase-shift circuit, which further attenuates the PCS transmission signal when transmitting the PCS signal, is provided in the DCS Rx terminal side of the phase-shift circuit.

Abstract: A high-frequency composite component for selectively switching a GSM-system signal path and a DCS-system signal path for a signal transmitted to or received from an antenna terminal by a diplexer. Transmission-side input terminals and reception-side balanced output terminals to be switched by high-frequency switches are included in the GSM and the DCS systems. Matching elements include inductors and capacitors that are inserted between the reception-side balanced output terminals and the output side of surface acoustic wave filters.