| 摘要 |
<p>A transmitter for a portable electronic device comprises a mixer, a digital-to- analogue converter (204), a driver stage (210) and a power amplifier (212). The transmitter comprises furthermore a control circuit (220, 228) that is connected to the output of the power amplifier and to a look-up table (226) including values corresponding to ramp functions. By comparing the level of the transmitter output signal with target values provided eg. by said look-up table, an error signal is generated which in turn is used to adjust the gain and bias settings of at least one of the transmitter stages, eg. the power amplifier (212) or its driver stage (210).</p> |
