A Low-Power Ultra-Wideband CMOS True RMS Power Detector

This paper introduces a low-power ultra-wideband true root-mean-square power detector with a 0.13-mum CMOS process operating from 125 MHz to 8.5 GHz. The detector utilizes the MOS transistor's square-law characteristic in the strong inversion region to obtain the power information of the input RF signal, and its exponential characteristic in the weak inversion region to realize the linear-in-decibel output. Measured dynamic ranges are 20 dB at 125 MHz and 18 dB at 8.5 GHz, respectively, with tolerances of plusmn0.5-dB error. WiMedia-ultrawideband and wireless local area network 802.11a signals with different modulation techniques and data rates are measured. The integrated detector operates at 1.2-V supply voltage, and its static power consumption is 0.18 mW.