| 摘要 |
A novel and useful load compensation circuit and associated pre-power amplifier constructed therefrom. The load compensation circuit functions to maintain a nearly constant output impedance of the pre-power amplifier by use of a switch matrix comprising a plurality of transistors. The switch matrix is placed in parallel with the output of the pre-power amplifier (PPA). Transistors are turned on or off within the load compensation switch matrix so as to maintain a nearly constant output impedance of the PPA throughout the entire modulation range. At maximum PPA output power, all transistors in the load compensation switch matrix are turned off thereby minimizing the extra output loading and reducing the overall power output. As output power decreases, additional numbers of transistors in the load compensation switch matrix are turned on so as to maintain a constant output impedance of the PPA.
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