A Direct Digital Synthesis Transmitter for 5G Applications With Low-Resolution DACs

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 71; no. 9; pp. 4166 - 4170
• Main Authors: Chang, Yu-Chen, Chen, You-Huei, Chen, Jau-Horng, Chen, Yi-Jan Emery
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2024; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: 5G mobile communication; Digital to analog converters; Digital-to-analog converter; direct digital synthesis; Frequency modulation; High resolution; Nonlinearity; Power amplifiers; Power harmonic filters; Pulse duration modulation; Quantization (signal); Radio frequency; Radio transmitters; Signal resolution; Synthesis; transmitter; Transmitters; Wireless communication systems
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2024.3381527

Conventional radio frequency (RF) transmitters frequently necessitate a pair of high-resolution, high-speed digital-to-analog converters (DACs) to ensure a specific level of linearity in wireless communication systems. Nevertheless, the high-resolution DACs escalate power consumption and area requirements and intensify the need for heat dissipation mechanisms. This brief presents a direct digital synthesis (DDS) transmitter using a pair of RF DACs with just 2 bits of resolution. The DDS transmitter, which uses a proposed digital pulse-width modulation signal with dithering, is resistant to power amplifier (PA) nonlinearity. Tested with 5G uplink signals and a pair of nonlinear PAs at 836.5 MHz, the transmitter could pass the stringent spectral requirements for 5G applications without using any digital predistortion or calibration techniques.