A CMOS digital-to-RF transmitter with filtering for IEEE 802.15.4a applications

Abstract

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 current-scaling digital-to-analog converter (DAC) circuit building block, named as digital-to-RF with filtering converter (DRFC). Moreover, the capability to handle data with high datarate is added to DRFC. Specifically, digital finite impulse response (FIR) filtering can be realized without high frequency sampling signal, and therefore, system integrity is enhanced. 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 17 and 40 dB. It means that the proposed circuit can achieve the required spectrum mask performance of the IEEE 802.15.4a UWB PHY.