| 摘要 |
Simplified, efficient multiple-transistor power amplifiers provide high power and high impedance while avoiding the use of RF power divider and combiner circuits. The input signal is directly applied to a first transistor, amplified, and supplied to the succeeding transistor, and so on, for amplification in series. Feedback is provided between the drain of the last transistor and the gates of all the transistors. Series connection of the transistors allows their power outputs and their output impedances to be summed, such that no RF output combiner is required. In a first high voltage embodiment of the amplifier of the invention, e.g., as used for satellite transmission, bias voltage is provided in series. In a second low voltage embodiment, suitable for use in cordless telephones and other battery-powered equipment, bias voltage Vds is provided separately across the drain and source terminals of each transistor, through paired chokes.
|
