Design of a Wideband Compact CMOS Integrated Attenuator with Low Insertion Loss and High Accuracy

This paper presents an integrated attenuator (IATT) with 40nm bulk COMS process. The IATT that works from 15GHz to 20GHz can be used in phased array system and it only employs MOSFET rather than poly silicon resistors in the main signal path and can cover attenuation range up to 14 dB by step of 2 dB. Furthermore, the root-mean-square (RMS) attenuation error can be less than 0.15dB. Due to the integrated structure the IATT only occupies 0.167 mm2 including inductors (inds) and 0.0158 mm2 excluding inductors. Besides, the IATT also shows a relative low insertion loss less than 3dB. By adopting the shunt capacitor (cap) compensation technique the RMS phase error of the IATT can be less than 0.5°.