Semiconductor device and power amplifier
AssigneeMurata Manufacturing Co., Ltd.
InventorsMitsuo Ariie, Yasutaka Sugimoto
Life of this patent
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Abstract
A semiconductor device 1 includes a plurality of amplifier circuits 2 connected in parallel between an input terminal RFin and an output terminal RFout. Each of the amplifier circuits 2 includes an HBT 3, an oscillation stabilizing circuit 4 connected between the input terminal RFin and a base B of the HBT 3, and a ballast resistor 5 connected between a bias terminal Bin and the base B of the HBT 3. The oscillation stabilizing circuit 4 includes a resistor 6 and a capacitor 7 connected in parallel. Thus, thermorunaway of the HBT 3 can be prevented using the ballast resistor 5, and the stability against oscillation can be improved using the oscillation stabilizing circuit 4 even at low frequencies.
Claims16
A semiconductor device comprising a plurality of high frequency amplifier circuits connected in parallel between an input terminal and an output terminal,
- wherein each of the amplifier circuits includes a bipolar transistor, a collector of the bipolar transistor being connected to the output terminal,
- an oscillation stabilizing circuit connected between the input terminal and a base of the bipolar transistor, the oscillation stabilizing circuit having a resistive component for low frequency signals and a substantially short-circuited component for high frequency signals, and
- a ballast circuit for preventing thermorunaway of the bipolar transistor, one end of the ballast circuit being connected to a bias terminal, the other end being connected to a point between the oscillation stabilizing circuit and the base of the bipolar transistor,
- wherein a distortion reducing resistor for reducing distortion of high frequency signals at the output terminal is connected between the input terminal and the bias terminal.
A semiconductor device comprising a plurality of high frequency amplifier circuits connected in parallel between an input terminal and an output terminal,
- wherein each of the amplifier circuits includes a bipolar transistor, a collector of the bipolar transistor being connected to the output terminal,
- an oscillation stabilizing circuit connected between the input terminal and a base of the bipolar transistor, the oscillation stabilizing circuit having a resistive component for low frequency signals and a substantially short-circuited component for high frequency signals, and
- a ballast circuit for preventing thermorunaway of the bipolar transistor, one end of the ballast circuit being connected to a bias terminal, the other end being connected to a point between the oscillation stabilizing circuit and the base of the bipolar transistor,
- wherein the oscillation stabilizing circuit includes an RC parallel circuit in which a resistor and a capacitor are connected in parallel,
- wherein the ballast circuit includes a ballast resistor connected between the bias terminal and the base of the bipolar transistor, and
- wherein a distortion reducing resistor for reducing distortion of high frequency signals at the output terminal is connected between the input terminal and the bias terminal.
A semiconductor device comprising a plurality of high frequency amplifier circuits connected in parallel between an input terminal and an output terminal,
- wherein each of the amplifier circuits includes a bipolar transistor, a collector of the bipolar transistor being connected to the output terminal,
- an oscillation stabilizing circuit connected between the input terminal and a base of the bipolar transistor, the oscillation stabilizing circuit having a resistive component for low frequency signals and a substantially short-circuited component for high frequency signals, and
- a ballast circuit for preventing thermorunaway of the bipolar transistor, one end of the ballast circuit being connected to a bias terminal, the other end being connected to a point between the oscillation stabilizing circuit and the base of the bipolar transistor;
- wherein a distortion reducing resistor for reducing distortion of high frequency signals at the output terminal is connected between the input terminal and the bias terminal;
- wherein the ballast circuit includes a ballast resistor connected between the bias terminal and the base of the bipolar transistor;
- wherein the resistance of the oscillation stabilizing resistor is at least twice the resistance of the ballast resistor.
A semiconductor device comprising a plurality of high frequency amplifier circuits connected in parallel between an input terminal and an output terminal,
- wherein each of the amplifier circuits includes a bipolar transistor, a collector of the bipolar transistor being connected to the output terminal,
- an oscillation stabilizing circuit connected between the input terminal and a base of the bipolar transistor, the oscillation stabilizing circuit having a resistive component for low frequency signals and a substantially short-circuited component for high frequency signals, and
- a ballast circuit for preventing thermorunaway of the bipolar transistor, one end of the ballast circuit being connected to a bias terminal, the other end being connected to a point between the oscillation stabilizing circuit and the base of the bipolar transistor;
- wherein a distortion reducing resistor for reducing distortion of high frequency signals at the output terminal is connected between the input terminal and the bias terminal;
- wherein the ballast circuit includes a ballast resistor connected between the bias terminal and the base of the bipolar transistor;
- wherein the resistance of the ballast resistor is greater than that of the distortion reducing resistor.
Dependencies are inferred from the claim text.