| 摘要 |
<p>A method for increasing the maximum useable supply voltage in an amplifier circuit is presented. A self-biased cascode amplifier circuit includes a first MOSFET and a second MOSFET connected in series and coupled between a DC voltage source terminal and a common terminal. An RF input signal terminal is coupled to a gate electrode of the first MOSFET, and the gate of the second MOSFET is connected between a resistor and a capacitor connected in series between the drain of the second MOSFET and the source of the first MOSFET. In preferred embodiments a unidirectionally-conducting boosting sub-circuit is coupled between a drain electrode and the gate electrode of the second MOSFET, which may comprise a diode-resistive sub-circuit, or a third MOSFET connected across a resistive voltage divider. The output of the amplifier circuit is taken from the drain electrode of the second MOSFET. These configuration permits the first and second MOSFETs to withstand a larger output voltage swing, thus permitting the use of a higher supply voltage and increased output power, without the necessity of complex biasing voltages.</p> |
