A mean square power detector, comprising: (a) a variable gain amplifier, comprising: a plurality of amplification elements arranged to generate amplified representations of an RF input signal at a plurality of nodes; a plurality of controllable response elements each having an input coupled to a different one of the plurality of nodes to receive a different one of the amplified representations of the RF input signal; a scale factor generator coupled to each of the controllable response elements, the scale factor generator receiving a gain control signal and generating scale factor signals for varying the response of each of the controllable response elements such that as the scale factor generator sweeps through a full range of the gain control signal, the response of each of the controllable response elements is, in succession, increased smoothly to a peak and thereafter decreased smoothly to a lower level to produce a scaled output; and a summing element coupled to the plurality of controllable response elements for combining the scaled outputs of the plurality of controllable response elements to generate an output of the variable gain amplifier having a given gain range, the mean square power detector further comprising: (b) a squaring power detector coupled to the variable gain amplifier for producing a detected signal from the output of the variable gain amplifier; and (c) an integrator coupled to the squaring power detector for integrating the difference between the detected signal received from the squaring power detector and a reference signal to provide an output representative of the mean square or root mean square of the RF input signal. (a) a variable gain amplifier, comprising: a plurality of amplification elements arranged to generate amplified representations of an RF input signal at a plurality of nodes; a plurality of controllable response elements each having an input coupled to a different one of the plurality of nodes to receive a different one of the amplified representations of the RF input signal; a scale factor generator coupled to each of the controllable response elements, the scale factor generator receiving a gain control signal and generating scale factor signals for varying the response of each of the controllable response elements such that as the scale factor generator sweeps through a full range of the gain control signal, the response of each of the controllable response elements is, in succession, increased smoothly to a peak and thereafter decreased smoothly to a lower level to produce a scaled output; and a summing element coupled to the plurality of controllable response elements for combining the scaled outputs of the plurality of controllable response elements to generate an output of the variable gain amplifier having a given gain range, the mean square power detector further comprising: (b) a squaring power detector coupled to the variable gain amplifier for producing a detected signal from the output of the variable gain amplifier; and (c) an integrator coupled to the squaring power detector for integrating the difference between the detected signal received from the squaring power detector and a reference signal to provide an output representative of the mean square or root mean square of the RF input signal. a plurality of amplification elements arranged to generate amplified representations of an RF input signal at a plurality of nodes; a plurality of controllable response elements each having an input coupled to a different one of the plurality of nodes to receive a different one of the amplified representations of the RF input signal; a scale factor generator coupled to each of the controllable response elements, the scale factor generator receiving a gain control signal and generating scale factor signals for varying the response of each of the controllable response elements such that as the scale factor generator sweeps through a full range of the gain control signal, the response of each of the controllable response elements is, in succession, increased smoothly to a peak and thereafter decreased smoothly to a lower level to produce a scaled output; and a summing element coupled to the plurality of controllable response elements for combining the scaled outputs of the plurality of controllable response elements to generate an output of the variable gain amplifier having a given gain range, (b) a squaring power detector coupled to the variable gain amplifier for producing a detected signal from the output of the variable gain amplifier; and (c) an integrator coupled to the squaring power detector for integrating the difference between the detected signal received from the squaring power detector and a reference signal to provide an output representative of the mean square or root mean square of the RF input signal.