A 55-dB dynamic range wideband RF logarithmic power detector with temperature and DC offset compensation

Abstract

A wideband RF logarithmic power detector with large dynamic range is presented in this work. The power detector fabricated in 180-nm SiGe process employs the successive approximation technique over a 6-stage cascaded amplifier chain. A cross-coupled cascode amplifier architecture is proposed to expand bandwidth up to 8GHz. With a temperature compensation circuit and a DC offset compensation loop, the detector provides consistent logarithmic performance at different temperatures in band, which can be applied in highly reliable RF systems. The measured input dynamic range is larger than 50dB in 1MHz∼8GHz with less than ±1dB error and 55dB at 8GHz with less than ±3dB error. The measured temperature drift is less than ±1.0dB at 5GHz over the temperature range from -40 to 85℃.