A 2.6-GHz Partial-Envelope Delta-Sigma-Digitized Carrier-Bursting Transmitter

This letter presents the implementation and measurement results of a partially digitized envelope-based carrier-bursting transmitter operating at 2.6 GHz. The transmitter consists of two chips, in this case: a partial-envelope delta–sigma modulator (PEDSM) and an up-conversion mixer with 130-nm CMOS technology. A second-order continuous-time delta–sigma modulator with a 622-MHz sampling clock is designed as an envelope digitizer in the PEDSM. With a long-term evolution signal with a peak-to-average power ratio of 8.7 dB, the fabricated transmitter showed a coding efficiency of 90.4% and an error vector magnitude (EVM) of 3.44% for a PEDSM threshold level of 1/3.