A RF/DC current-mode detector for BiST and digital calibration of current-driven mixers

Abstract

This paper presents a CMOS RF/DC current-mode detector as an essential requirement to realize Built-in Self Test (BiST) and calibration functionalities for current-mode based RFICs and demonstrates its application on the calibration of a current-driven passive mixer. A method is presented to extract test friendly DC features from the RF signal, without deteriorating the performance of test blocks in the transceiver. Simulation performance with IBM 90-nm process using 1.2 V power supply shows that the proposed detector is able to provide an RF to DC conversion gain of 35 mV/dB in a dynamic range of 25 dB from 900 MHz to 10 GHz. The current-mode detector is then applied in the IP2 digital calibration technique on the downconversion mixer under several corner conditions. Simulation results confirm the feasibility of the calibration as IIP2 improves more than 20 dBm.