求帮忙下载IEEE关于RF-DAC的文章

fengsui

A full D-band multi-Gbit RF-DAC in 90 nm SiGe BiCMOS based on passive vector aggregation
Ultrawideband RF-IQ Modulator Using Segmented Nonlinearly Scaled RF-DACs and Nonoverlap LO Signals
A 6-bit 56-GSa/s DAC in 55 nm SiGe BiCMOS
A 13.2-dBm, 138-GHz I/Q RF-DAC with 64-QAM and OFDM free-space constellation formation

多谢！