A low-power CMOS digital transmitter for IEEE 802.15.4a applications

The proposed CMOS digital-to-RF transmitter with filtering, which is designed in TSMC 0.18 um CMOS technology, merges RF functions, including pulse shape filtering and frequency up-mixing into a simple DAC (digital-to-analog converter) circuit building block, named as DRFC (digital-to-RF with filtering converter). Moreover, the capability to handle data with wide bandwidth is added to DRFC without high frequency sampling signal. The DRFC transmitter module is applied to IR UWB systems for verifying the reliability in performance, and the simulation shows that the transmitter achieves ACPR of 5 and 15 dB. It means that the proposed circuit can achieve the required spectrum mask performance of the IEEE 802.15.4a UWB PHY.