Patent ID: 8792579

Claim:
A transmission circuit, comprising: a variable gain amplifier configured to receive a radio frequency (RF) modulated signal, wherein an output power of the RF signal is adjusted in an open loop mode control by changing a gain of the variable gain amplifier in accordance with a pre-specified reference value; a subtraction block configured to receive an output of the variable gain amplifier and a scaled-up version of the RF modulated signal generated by modifying the RF modulated signal, and to generate a measurement loop error as the difference between the output of the variable gain amplifier and the scaled-up version of the RF modulated signal; a controller configured to receive and measure the measurement loop error in the open loop mode control, and to generate a correction applied to prevent error when transitioning to the closed loop mode control; an absolute value generator configured to receive the RF modulated signal and to generate an absolute representation of the RF modulated signal; and a programmable amplifier located downstream of the absolute value generator and configured to scale up a received signal to generate the scaled-up version of the RF modulated signal based upon the pre-specified reference value.