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US 8,253,485 B2Granted
Power amplifier
AssigneeSony Europe Limited
InventorJohn Christopher Clifton
Life of this patent
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Abstract
A power amplifier comprises a series stack of power amplifier devices, connected in parallel to the amplifier input for receiving an RF input signal, and having output terminals being connected in series to the amplifier output. An intermediate coupling capacitor is connected between each adjacent pair of power amplifier devices in the series stack of power amplifier devices for DC isolation of said power amplifier devices. This reduces the required DC supply voltage, as well as allowing shorting of individual power amplifier devices in response to variation in the DC supply voltage.
Claims16
A power amplifier for amplifying an RF input signal, the power amplifier comprising:
- an amplifier input for receiving the RF input signal, and an amplifier output for outputting an amplified RF output signal;
- a series stack of power amplifier devices, each arranged to amplify a signal supplied to an input terminal thereof and to generate an amplified signal across two output terminals thereof, the input terminals of each power amplifier being connected in parallel to the amplifier input for receiving the RF input signal, and the output terminals of the power amplifier devices being connected in series to the amplifier output;
- and
- a respective intermediate coupling capacitor connected between the output terminals of each adjacent pair of power amplifier devices in said series stack of power amplifier devices for DC isolation of said power amplifier devices, the output terminals of each power amplifier device being connected to respective DC bias voltage supply lines, and
- wherein, in respect of at least one of the power amplifier devices, the respective DC bias voltage supply lines to which the output terminals are connected include a switch arrangement capable of disconnecting the DC bias voltage, and the respective DC bias voltage supply line to which the input terminal is connected is itself connected to a variable DC bias voltage supply capable of being controlled to provide a normal DC bias voltage or a high DC bias voltage.
2 more elements
A method of controlling a power amplifier that comprises:
- an amplifier input for receiving the RF input signal, and an amplifier output for outputting an amplified RF output signal;
- a series stack of power amplifier devices, each arranged to amplify a signal supplied to an input terminal thereof and to generate an amplified signal across two output terminals thereof, the input terminals of each power amplifier being connected in parallel to the amplifier input for receiving the RF input signal, and the output terminals of the power amplifier devices being connected in series to the amplifier output;
- and
- a respective intermediate coupling capacitor connected between the output terminals of each adjacent pair of power amplifier devices in said series stack of power amplifier devices for DC isolation of said power amplifier devices, the output terminals of each power amplifier device being connected to respective DC bias voltage supply lines,
- the method comprising selectively shorting out at least one of the power amplifier devices in response to either the DC supply voltage supplied to the power amplifier or the output power of transmission.
2 more elements
A power amplifier for amplifying an RF input signal, the power amplifier comprising:
- an amplifier input for receiving the RF input signal, and an amplifier output for outputting an amplified RF output signal;
- a series stack of power amplifier devices, each arranged to amplify a signal supplied to an input terminal thereof and to generate an amplified signal across two output terminals thereof, the input terminals of each power amplifier being connected in parallel to the amplifier input for receiving the RF input signal, and the output terminals of the power amplifier devices being connected in series to the amplifier output;
- a respective intermediate coupling capacitor connected between the output terminals of each adjacent pair of power amplifier devices in said series stack of power amplifier devices for DC isolation of said power amplifier devices, the output terminals of each power amplifier device being connected to respective DC bias voltage supply lines;
- and
- a plurality of amplifier output channels for outputting amplified signals of different RF frequencies to respective impedance matching circuits and a transmit multi-through switch arrangement connected between said amplifier output and said plurality of amplifier output channels for supplying the amplified signal to one of the amplifier output channels in accordance with its RF frequency.
2 more elements
Dependencies are inferred from the claim text.