| 摘要 |
<p>An output power control circuit of a power amplifier connected to the power amplifier comprises a first operational amplifier (AMP0), a first PMOS transistor, and a current sampling module (102). A negative input end of the first operational amplifier (AMP0) receives a power control signal. A gate of the first PMOS transistor is connected to an output end of the first operational amplifier (AMP0), a source is connected to an external power supply, and a drain is grounded by means of a first voltage offloading network (104). A power supply end of the power amplifier is connected to the drain of the first PMOS transistor, an input end accesses a signal to be amplified and an output end amplifies a signal. The current sampling module (102) samples a current of the first PMOS transistor to form a sampled current, and provides a negative feedback signal to a positive input end of the first operational amplifier (AMP0) according to the sampled current, so that a total power of the power amplifier is unchanged. The technical solutions can maintain a total power of a power amplifier unchanged, so that a correspondence between a load impedance change and an output power is weakened and power control is more accurate.</p> |
