Parallel PWMs Based Fully Digital Transmitter With Wide Carrier Frequency Range

With the rapid development of multi-standard wireless communication and radiosoftware, handheld devices that support low power, low cost, high linearity, wide carrierfrequency, high energy efficiency, multimode and multiband have gradually developed intokey technologies of wireless transmitters.In this paper, by combining intermediate-frequency pulse-width modulators(IF-PWMs) for high CF and pre-corrected carrier-frequency pulse-width modulators(CF-PWMs) for low CF, a fully digital transmitter is presented with wide CF range, highlinearity, low power and high efficiency.First, the paper briefly introduces the background of the topic, and illustrates thearrangement of the contents.Second, the paper makes some descriptions of the basic principle of the transmitter,introduces several common transmitter architecture, and analysis the advantages anddisadvantages of various transmitter architecture.Third, according to the recent as well as the future development trend of radiotransmitter estimates, the author presents the architecture design ideas. By the design ofparallel IF-PWM and CF-PWM, a wide frequency range is covered. Polar coordinates andquadrature up conversion technology can ensure the accuracy of the modulation. Using theswitching power amplifier and full digital circuit can reduce system power consumptionand improve the efficiency. Digital envelope pre-correction algorithm and90°phase shiftoperation can ensure that the CF-PWM modulation linearity. Inductive differential powercombiner with2-level quadrature operation is proposed under single-supply processsupporting only0and1levels to achieve the3-level up conversion. Unit-delayauto-calibration is proposed to ensure the high robustness.Finally, the key sub module design of the circuit is proposed and designed in180nmCMOS. According to the deviation of the entire system, deep data analysis is done. Proposesolutions for problems detecting in the test and the later outlook.