A 1.2-V 30.4-dBm OIP3 reconfigurable analog baseband channel for UMTS/WLAN transmitters

This paper presents a reconfigurable universal mobile telecommunication systems [(UMTS) and wireless local area network (WLAN) mode)] analog baseband transmitter channel composed of a current steering digital-analog converter (DAC), a transimpedance stage, and a low-pass reconstruction filter. The device operates from a single 1.2-V supply voltage while guaran teeing the high-linearity UMTS/WLAN standard requirements. It can be digitally programmed to process WLAN 802.11a/b/g and UNITS signals, by adjusting the DAC conversion frequency and the low-pass filter cutoff frequency. For them WLAN mode, the DAC operating frequency and the filter bandwidth are set to 100 and 11 MHz, respectively, while for the UNITS mode, they are equal to 50 and 2.11 MHz. The device is realized in a 1.2-V 0.13-mu m standard CMOS technology. The die area occupation, equal to 0.9 mm(2), has been minimized by optimizing the component sharing for the two operation modes. The proposed circuit achieves a 30.4 dBm third-order output referred intermodulation intercept point (OIP3) for the WLAN mode, and a 31.5 dBm-OIP3 when configured for the UNITS mode, while the spurious-free dynamic range is 58 dB for WLAN mode, and 60 dB for UNITS mode. The power consumption is optimized according to the operation mode and is 19.44 mW in WLAN mode and 16.8 mW in UNITS mode.