Abstract: Provided is a compact high frequency power amplifier having a high degree of freedom of design with respect to a gain fluctuation immediately after start-up of an amplifier. The high frequency power amplifier includes a speed-up circuit that transiently increases a reference voltage during rise of a control voltage to increase an amount of bias supplied to an amplification transistor from a bias circuit. The speed-up circuit includes a capacitor and an overshoot control circuit. The overshoot control circuit determines an increasing amount of the reference voltage when the reference voltage is transiently increased according to a charge amount charged in the capacitor, and the overshoot control circuit also determines a time constant in charging and discharging the capacitor.

Abstract: Provided is a compact high frequency power amplifier having a high degree of freedom of design with respect to a gain fluctuation immediately after start-up of an amplifier. The high frequency power amplifier includes a speed-up circuit that transiently increases a reference voltage during rise of a control voltage to increase an amount of bias supplied to an amplification transistor from a bias circuit. The speed-up circuit includes a capacitor and an overshoot control circuit. The overshoot control circuit determines an increasing amount of the reference voltage when the reference voltage is transiently increased according to a charge amount charged in the capacitor, and the overshoot control circuit also determines a time constant in charging and discharging the capacitor.

Abstract: The present invention provides a radio frequency switch and a radio frequency module having excellent distortion characteristics without causing a further insertion loss and a greater chip size. The radio frequency switch includes: input-output terminals which are for inputting and outputting a radio frequency signal; a basic switching unit provided between two of the input-output terminals; and a control terminal which receives a control voltage for controlling conduction and interruption of the basic switching unit. The basic switching unit includes field effect transistors (FETs) connected in multiple stages, each of the FETs being a meandered FET having a meandered gate electrode, and among the FETs, one of the FETs has a finger length shorter than finger lengths of rest of the FETs, the one of the FETs electrically located closest to one of the input-output terminals.

Abstract: Provided are a detector circuit which has a simple circuit configuration, is capable of indicating an accurate power according to a load fluctuation of a radio frequency power amplifier or a difference in a modulation mode, and can be easily incorporated in the radio frequency power amplifier, and a wireless communication system using the detector circuit. The detector circuit 10 includes a detecting resistor 11 for detecting a part of a current flowing from a bias circuit 6, and a current-voltage conversion circuit 12 for converting a current obtained through the detecting resistor 11 into a voltage.

Abstract: Provided are a detector circuit which has a simple circuit configuration, is capable of indicating an accurate power according to a load fluctuation of a radio frequency power amplifier or a difference in a modulation mode, and can be easily incorporated in the radio frequency power amplifier, and a wireless communication system using the detector circuit. The detector circuit 10 includes a detecting resistor 11 for detecting a part of a current flowing from a bias circuit 6, and a current-voltage conversion circuit 12 for converting a current obtained through the detecting resistor 11 into a voltage.

Abstract: A small, high performance high frequency power amplifier enables easily adjusting and switching the impedance. The high frequency power amplifier module includes a first semiconductor chip including one or a plurality of high frequency amplification devices, and a second semiconductor chip including one or more high frequency matching circuit devices and one or more switching devices. The second semiconductor chip includes the matching circuit for a high frequency amplifier device. The second semiconductor chip also includes a circuit composed of a capacitance and a switching device connected in series or parallel to the capacitance. The switching device switches on or off so that the capacitance is connected or is not connected as a part of the matching circuit.

Abstract: A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a first amplification stage having a first hetero bipolar transistor of which collector output is detected; a second amplification stage which is prior to the first amplification stage and which has a second hetero bipolar transistor in which the detection result is reflected; a first resistor provided between a collector of the second hetero bipolar transistor and a power supply; and a protection circuit which is connected between a collector of the first hetero bipolar transistor and the collector of the second hetero bipolar transistor, detects output from the collector of the first hetero bipolar transistor, and reduces a voltage of the collector of the second hetero bipolar transistor in accordance with the detected output.

Abstract: A small, high performance, multifunctional high frequency circuit that is multiband and multimode compatible reduces loss from a switch formed on the output side of a final stage amplification unit. The final stage amplification unit power amplifies an input signal and outputs an amplified signal. A first matching circuit impedance converts the amplified signal input thereto at a first input impedance, and outputs a first impedance-converted signal at a first output impedance. A control unit that generates a control signal denoting signal path selection information. A switch unit selects one of at least two signal paths based on the control signal, passes the first impedance-converted signal at an on impedance through the selected path, and outputs the pass signal. A second matching circuit impedance converts a pass signal input thereto at a second input impedance, and outputs a second impedance-converted signal at a second output.

Abstract: Provided are a detector circuit which has a simple circuit configuration, is capable of indicating an accurate power according to a load fluctuation of a radio frequency power amplifier or a difference in a modulation mode, and can be easily incorporated in the radio frequency power amplifier, and a wireless communication system using the detector circuit. The detector circuit 10 includes a detecting resistor 11 for detecting a part of a current flowing from a bias circuit 6, and a current-voltage conversion circuit 12 for converting a current obtained through the detecting resistor 11 into a voltage.

Abstract: A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a first amplification stage having a first hetero bipolar transistor of which collector output is detected; a second amplification stage which is prior to the first amplification stage and which has a second hetero bipolar transistor in which the detection result is reflected; a first resistor provided between a collector of the second hetero bipolar transistor and a power supply; and a protection circuit which is connected between a collector of the first hetero bipolar transistor and the collector of the second hetero bipolar transistor, detects output from the collector of the first hetero bipolar transistor, and reduces a voltage of the collector of the second hetero bipolar transistor in accordance with the detected output.

Abstract: A small, high performance, multifunctional high frequency circuit that is multiband and multimode compatible reduces loss from a switch formed on the output side of a final stage amplification unit. The final stage amplification unit power amplifies an input signal and outputs an amplified signal. A first matching circuit impedance converts the amplified signal input thereto at a first input impedance, and outputs a first impedance-converted signal at a first output impedance. A control unit that generates a control signal denoting signal path selection information. A switch unit selects one of at least two signal paths based on the control signal, passes the first impedance-converted signal at an on impedance through the selected path, and outputs the pass signal. A second matching circuit impedance converts a pass signal input thereto at a second input impedance, and outputs a second impedance-converted signal at a second output.

Abstract: A radio frequency signal RF is input to a base of each of transistors TR1 through TRn via a corresponding capacitor among capacitors C1 through Cn, is amplified, and is output from a collector of each of the transistors TR1 through TRn. An emitter of each of the transistors TR1 through TRn is grounded. A bias voltage DC given from a bias circuit Bias is supplied to the base of each of the transistors TR1 through TRn via a corresponding resistor among resistors Ra1 through Ran. A signal line for the bias voltage DC is connected to an input line for the radio frequency signal RF via the bridge resistor R in a direct current manner.

Abstract: A high-frequency power amplifier with a temperature compensation function for power amplifying a high-frequency signal, includes: a power amplifying transistor having an emitter grounded; a high power output bias circuit that supplies a high power output current corresponding to a high power output of the high-frequency power amplifier to the power amplifying transistor; and a low power output bias circuit that supplies a low power output current corresponding to a low power output of the high-frequency power amplifier to the power amplifying transistor.

Abstract: An output level of a transmission apparatus 1 is determined, depending on an attenuation amount of an attenuator 30, a gain of one of a high output level amplification section 17 and a low output level amplification section 18, which is used. A reference voltage Vref(H) is discontinuously changed. Depending on the magnitude of the reference voltage Vref(H), it is determined which of the amplification sections 17, 18 is used, and the attenuation amount of the attenuator 30 and the gain of the amplification section 17, 18 are also determined. When the magnitude of the reference voltage Vref(H) is changed, a sum of the attenuation amount of the attenuator 30 and a gain change amount of a switch amplification section 19 is substantially zero.

Abstract: A small, high performance high frequency power amplifier enables easily adjusting and switching the impedance. The high frequency power amplifier module includes a first semiconductor chip including one or a plurality of high frequency amplification devices, and a second semiconductor chip including one or more high frequency matching circuit devices and one or more switching devices. The second semiconductor chip includes the matching circuit for a high frequency amplifier device. The second semiconductor chip also includes a circuit composed of a capacitance and a switching device connected in series or parallel to the capacitance. The switching device switches on or off so that the capacitance is connected or is not connected as a part of the matching circuit.

Abstract: A high-frequency power amplifier with a temperature compensation function for power amplifying a high-frequency signal, includes: a power amplifying transistor having an emitter grounded; a high power output bias circuit that supplies a high power output current corresponding to a high power output of the high-frequency power amplifier to the power amplifying transistor; and a low power output bias circuit that supplies a low power output current corresponding to a low power output of the high-frequency power amplifier to the power amplifying transistor.

Abstract: A high frequency amplifier circuit has a bias supplying transistor for supplying a bias current to an amplifying transistor, and first and second temperature compensating transistors for compensating the temperature properties of the base voltage of the bias supplying transistor. The base of the bias supplying transistor and the base of the first temperature compensating transistor are connected by a resistor in order to keep the base voltage of the bias supplying transistor approximately constant without following a change in the base voltage of the first temperature compensating transistor, even in the case where such a change occurs. The temperature compensating transistors, the bias supplying transistor and the resistor are formed in one multi-emitter type transistor.

Abstract: A radio frequency signal RF is input to a base of each of transistors TR1 through TRn via a corresponding capacitor among capacitors C1 through Cn, is amplified, and is output from a collector of each of the transistors TR1 through TRn. An emitter of each of the transistors TR1 through TRn is grounded. A bias voltage DC given from a bias circuit Bias is supplied to the base of each of the transistors TR1 through TRn via a corresponding resistor among resistors Ra1 through Ran. A signal line for the bias voltage DC is connected to an input line for the radio frequency signal RF via the bridge resistor R in a direct current manner.

Abstract: An output level of a transmission apparatus 1 is determined, depending on an attenuation amount of an attenuator 30, a gain of one of a high output level amplification section 17 and a low output level amplification section 18, which is used. A reference voltage Vref(H) is discontinuously changed. Depending on the magnitude of the reference voltage Vref(H), it is determined which of the amplification sections 17, 18 is used, and the attenuation amount of the attenuator 30 and the gain of the amplification section 17, 18 are also determined. When the magnitude of the reference voltage Vref(H) is changed, a sum of the attenuation amount of the attenuator 30 and a gain change amount of a switch amplification section 19 is substantially zero.

Abstract: A high frequency amplifier circuit has a bias supplying transistor for supplying a bias current to an amplifying transistor, and first and second temperature compensating transistors for compensating the temperature properties of the base voltage of the bias supplying transistor. The base of the bias supplying transistor and the base of the first temperature compensating transistor are connected by a resistor in order to keep the base voltage of the bias supplying transistor approximately constant without following a change in the base voltage of the first temperature compensating transistor, even in the case where such a change occurs. The temperature compensating transistors, the bias supplying transistor and the resistor are formed in one multi-emitter type transistor.