| 摘要 |
The present invention generally relates to the field of automatic power control (APC) circuitries used in the analog front end of a mobile transmitter. It particularly refers to a power control circuitry (101M, 101N) and a corresponding method for controlling the power level (Pout) of an RF signal (x(t)) to be transmitted at the output port of a variable-gain power amplifier (105) by performing an additional regulation of the APC loop's reference signal (Vref). Thereby, it is proposed to increase the radiated RF power (Pout) in case a transmitting antenna (110) is mismatched to said power amplifier (105) in order to not release an ongoing call. In case there is a subject very close to the terminal antenna, the antenna load is changed and the increased reflected signal is measured. In a closed loop this increased reflected signal is mixed with a reference ramp signal (Vramp) which is used to calculate (S1A) a reference signal (Vref) representing the nominal power level (Pref) for the power (Pout) of the RF signal (x(t)) to be transmitted, which leads to an increasing of the radiated power and prevents said call from being released. The step of calculating (S1A) the reference signal (Vref) as a function of the reference ramp signal (Vramp) and a DC feedback signal (VPD) is realized by the substeps of multiplying (S1a′) a processed version (K·GOP·VPD) of the DC feedback signal (VPD) by the reference ramp signal (Vramp) and adding (S1a″) the output signal (Vramp·K·GOP·VPD) of the multiplication step (S1a) to the reference ramp signal (Vramp), thereby yielding said reference signal (Vref).
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