Patent ID: 7532869

Claim:
A radio frequency transmitter comprising: a baseband frequency stage including a digital to analog converter having an input for receiving an adjustable control voltage, inputs for receiving an in-phase (I) signal and a quadrature (Q) signal and outputs for corresponding analog signal components; a radio frequency output stage; and a power level control circuit including: a detector circuit having a detector input and a detector output, the detector input being connected to said radio frequency output stage; and a comparator circuit having a comparator input and a comparator output, said comparator input being configured to receive an output signal from said detector output and a reference signal, wherein said comparator output is connected to said digital analog converter to provide the adjustable control voltage on the basis of the detector output signal and the reference signal, wherein the comparator circuit includes a digital to analog converter control circuit and a comparator section, wherein the comparator section is configured to provide a comparison result in the form of at least one digital signal to said digital to analog converter control circuit, wherein said digital signal indicates when an output power of said output stage exceeds a first threshold, and wherein said digital signal indicates when an output power of said output stage is lower than a second threshold, wherein the second threshold is lower than said first threshold.