| 摘要 |
A high-efficiency configurable power amplifier (50) suitable for use in amplifying a signal (58) for wireless transmission by a portable unit provides a variable power output level, maximum efficiency of operation and battery power savings for the portable unit. The configurable power amplifier (50) includes a plurality of amplifier stages (51,52,53) with each stage having its own output configuration so that a selected number of desired output power levels for the power amplifier may be obtained directly from a selected amplifier stage. The amplifier stages also may be configured in tandem (by 54,55,56) such that the output of a first amplifier stage serves as an input to a second amplifier stage, and so forth, in order to obtain a broad range of selectable power output levels while maintaining the desired efficiency of operation. When not part of the amplifying circuitry, each one of unused amplifier stages is switched to an OFF state (by 57) wherein essentially no operating power is consumed by an amplifier stage when in this state. By employing the configurable power amplifier, the size, cost, and weight of the portable unit may be substantially reduced through use of a smaller capacity and less expensive battery or, alternatively, the talk time may be substantially increased if the same capacity battery is used. <IMAGE> |
