The Design of a Wide-Dynamic-Range and High-Linearity RMS Power Detector for mm-Wave Applications in 65 nm CMOS

In this paper, a wide dynamic range RMS power detector with an operating frequency from 24 GHz to 35 GHz mm-wave frequency is presented. The power detector is fabricated in a 65 nm CMOS process. It is composed of a power detector unit, a radio frequency signal attenuator and a linear proportional voltage adder. The equalization technique is used to achieve a good linearity performance. The input dynamic range of the power detector is expanded by using one radio frequency signal attenuator and five power detector units. The simulation results show the slope of VOUT versus input power remaining constant at around 0.06 V/dBm when the input signal power varies from -10 dBm to 10 dBm. The difference in output voltage varies by only 0.03 V when the input power varies from -10 to 0 dBm and 0 to 10 dBm. These all indicate that the proposed power detector achieves a good linearity performance. The measured results also show that the proposed power detector achieves a wide dynamic range and a high linearity performance from -10 dBm to 10 dBm. The detectable dynamic range is enhanced by 3.3 times compared to that achieved when only using one single power detector unit, while it only consumes about 0.75 mW under a 1.2 V supply voltage.