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

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 8 GHz. 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 50 dB in 1MHz similar to 8 GHz with less than +/- 1 dB error and 55 dB at 8 GHz with less than similar to 3 dB error. The measured temperature drift is less than similar to 1 :0 dB at 5 GHz over the temperature range from 40 to 85.