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 switch is constructed by connecting a first diode and a second diode that function as switching elements, inductors, capacitors, and resistors. One end of the resistor is connected between the first diode and the second diode, and the other end of the resistor is connected to the ground. Thus, charges accumulated in the diodes in the ON states are immediately released to ground via the resistor. Accordingly, quick switching from the transmission mode to the reception mode by switching of a control power supply terminal from ON to OFF is achieved.

Abstract: A high frequency switch includes electrically connected switching elements, such as a first diode, a second diode, inductors, capacitors, and a resistor. A diode having a smaller charge capacity in the ON state is used as the first diode, while a diode having a larger charge capacity in the ON state is used as the second diode. That is, the first and second diodes utilize different part number diodes. A diode part number having a smaller charge capacity is used as the first diode, while a diode part number having a larger charge capacity is used as the second diode. Alternatively, the charge capacity of diodes that belong to the same lot may be measured and classified, so that a smaller charge capacity diode is used as the first diode, while a larger charge capacity diode is used as the second diode.

Abstract: The invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.

Abstract: A high frequency switching component for being connected to a transmission circuit, a reception circuit, and an antenna to be used for switching to either a state in which the transmission circuit is connected to the antenna, or a state in which the reception circuit is connected to the antenna, comprising: a multilayer circuit board, on which there is formed a circuit including: a transmission circuit terminal to be connected to the transmission circuit; a reception circuit terminal to be connected to the reception circuit; an antenna terminal to be connected to be the antenna; a ground terminal; a first diode whose anode is connected to the transmission circuit terminal and the cathode thereof is connected to the antenna terminal; a second diode whose anode is connected to the reception circuit terminal and the cathode thereof is connected to the ground terminal; a signal line for connecting the transmission circuit terminal, the reception circuit terminal, and the antenna terminal via the first diode; and

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 mobile communication device, preferably in the form of a dual-band cellular phone, includes two communications systems supporting different frequency bands, such as DCS in the 1.8 GHz band and GSM in the 900 MHz band. The mobile communication device includes an antenna, a high-frequency composite unit, DCS and GSM transmitters, and DCS and GSM receivers. The high-frequency composite unit contains a diplexer, DCS and GSM high-frequency switches, DCS and GSM high-frequency filters or notch filters, and a directional coupler.

Abstract: A high frequency switching component for being connected to a transmission circuit, a reception circuit, and an antenna to be used for switching to either a state in which the transmission circuit is connected to the antenna, or a state in which the reception circuit is connected to the antenna, comprising: a multilayer circuit board, on which there is formed a circuit including: a transmission circuit terminal to be connected to the transmission circuit; a reception circuit terminal to be connected to the reception circuit; an antenna terminal to be connected to be the antenna; a ground terminal; a first diode whose anode is connected to the transmission circuit terminal and the cathode thereof is connected to the antenna terminal; a second diode whose anode is connected to the reception circuit terminal and the cathode thereof is connected to the ground terminal; a signal line for connecting the transmission circuit terminal, the reception circuit terminal, and the antenna terminal via the first diode; and

Abstract: The invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.

Abstract: A high frequency switching component for being connected to a transmission circuit, a reception circuit, and an antenna to be used for switching to either a state in which the transmission circuit is connected to the antenna, or a state in which the reception circuit is connected to the antenna, comprising: a multilayer circuit board, on which there is formed a circuit including: a transmission circuit terminal to be connected to the transmission circuit; a reception circuit terminal to be connected to the reception circuit; an antenna terminal to be connected to be the antenna; a ground terminal; a first diode whose anode is connected to the transmission circuit terminal and the cathode thereof is connected to the antenna terminal; a second diode whose anode is connected to the reception circuit terminal and the cathode thereof is connected to the ground terminal; a signal line for connecting the transmission circuit terminal, the reception circuit terminal, and the antenna terminal via the first diode; and

Abstract: The invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.

Abstract: The invention provides a composite high frequency component constituting a part of a microwave circuit having plural signal paths corresponding to their respective frequencies, comprising: a diplexer for coupling transmitting signals from the plural signal paths for transmission and distributing receiving signals into said plural signal paths for reception; plural high frequency switches for separating the plural signal paths into a transmission section and a reception section, respectively; plural filters introduced in the signal paths; said diplexer, said high frequency switch, and said filters being integrated into a ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers. According to the above described composite high frequency component, the diplexer, the high frequency switches, and the filters which constitute the composite high frequency component are integrated into the ceramic multi-layer substrate formed by lamination of plural ceramic sheet layers.

Abstract: A composite high frequency component and a mobile communication apparatus incorporating the same which needs no matching circuits and can easily be miniaturized. The composite high frequency component is constituted of a diplexer, high frequency switches, high frequency filters, and surface acoustic wave filters. The diplexer is formed by first inductors and first capacitors. The high frequency switches are formed by diodes, second inductors, and second capacitors. The high frequency filters are formed by third inductors and third capacitors.

Abstract: A composite high frequency component and a mobile communication apparatus incorporating the same which needs no matching circuits and can easily be miniaturized. The composite high frequency component is constituted of a diplexer, high frequency switches, high frequency filters, and surface acoustic wave filters. The diplexer is formed by first inductors and first capacitors. The high frequency switches are formed by diodes, second inductors, and second capacitors. The high frequency filters are formed by third inductors and third capacitors.

Abstract: A composite high frequency component and a mobile communication apparatus incorporating the same which needs no matching circuits and can easily be miniaturized. The composite high frequency component is constituted of a diplexer, high frequency switches, high frequency filters, and surface acoustic wave filters. The diplexer is formed by first inductors and first capacitors. The high frequency switches are formed by diodes, second inductors, and second capacitors. The high frequency filters are formed by third inductors and third capacitors.

Abstract: A mobile communication device, preferably in the form of a dual-band cellular phone, includes two communications systems supporting different frequency bands, such as DCS in the 1.8 GHz band and GSM in the 900 MHz band. The mobile communication device includes an antenna, a high-frequency composite unit, DCS and GSM transmitters, and DCS and GSM receivers. The high-frequency composite unit contains a diplexer, DCS and GSM high-frequency switches, DCS and GSM high-frequency filters or notch filters, and a directional coupler.

Abstract: A high frequency composite component is miniaturized and included in a mobile communication apparatus. The high frequency composite component includes a diplexer, a duplexer, and a high frequency switch. The diplexer is defined by first inductors and first capacitors. The duplexer is defined by second inductors and second capacitors, and the high frequency switch is defined by a first diode and a second diode, third inductors, and third capacitors.