An FPGA-based all-digital transmitter with 28-GHz time-interleaved delta-sigma modulation

An FPGA-based all-digital transmitter with 28-GHz ΔΣ-modulation is presented. For improving the operation frequency of ΔΣ modulator (DSM), a multi-channel look-ahead time-interleaved ΔΣ modulator is proposed. By implementing the proposed DSM in an FPGA, 28-GHz operation of DSM has been achieved. Furthermore, FPGA-based all-digital transmitter integrating the proposed DSM can satisfy the spectral mask of IEEE 802.11a WLAN standard in 5.2-GHz band. To the best of our knowledge, this is the first demonstration of an FPGA-based all-digital transmitter which can directly generate 5-GHz band WLAN signal.