A 1.2V-21dBm OIP3 4/sup th/-order active-g/sub m/-RC reconfigurable (UMTS/WLAN) filter with on-chip tuning designed with an automatic tool

Abstract

A 4/sup th/ order low-pass continuous-time filter for a UMTS/WLAN receiver of a reconfigurable terminal is presented. The filter uses two active-g/sub m/-RC biquad cells, where a single opamp is used for two poles and its unity-gain-bandwidth is comparable to the filter cut-off frequency. Thus, the opamp power consumption is strongly reduced with other closed-loop filter configuration. The cut-off frequency deviation due to the technological spread, aging and temperature variation is adjusted by an on-chip tuning circuit. The device in a 0.13/spl mu/m CMOS technology occupies a 0.9mm/sup 2/ area and consumes 3.4mW and 14.2mW for the UMTS and WLAN, respectively. The full chip has been designed using an automatic design tool and the experimental results agree with the expected performance.