An all-digital RF transmitter architecture based on jitter-enhanced PWM for flexible frequency applications

We propose a novel flexible jitter-enhanced pulse width modulation(PWM) hardware architecture, which aims to improve the modulation resolution while reducing the requirement of PWM frequency. The architecture creatively distributes the jitter effect uniformly to every radio frequency(RF) cycle corresponding to the same baseband cycle by controllable jitter, which provides a new modulation resolution growth method in the time domain. The architecture provides flexibility to adapt to different basebands and radio frequencies. By using jitter, the modulation resolution of this paper can improve 5.32 bit at most, and the EVM performance can reach -41.21dB. The architecture proposed in this paper can use lower PWM frequency of 400MHz, which greatly reduces the frequency requirement of switching power amplifier in RF transmitting system. The jitter method proposed in this paper significantly improves the low modulation resolution of the traditional PWM all-digital RF transmitter and greatly changes the efficiency of all digital transmitters in the wireless communication system.