Title
A 1.5–1.9-GHz All-Digital Tri-Phasing Transmitter With an Integrated Multilevel Class-D Power Amplifier Achieving 100-MHz RF Bandwidth
Abstract
We present a prototype RF transmitter with an integrated multilevel class-D power amplifier (PA), implemented in 28-nm CMOS. The transmitter utilizes tri-phasing modulation, which combines three constant-envelope phase-modulated signals with coarse amplitude modulation in the PA. This new architecture achieves the back-off efficiency of multilevel outphasing, without linearity-degrading discontinuities in the RF output waveform. Because all signal processing is performed in the time domain up to the PA, the entire system is implemented with digital circuits and structures, thus also enabling the use of synthesis and place-and-route CAD tools for the RF front end. The effectiveness of the digital tri-phasing concept is supported by extensive measurement results. Improved wideband performance is validated through the transmission of orthogonal frequency-division multiplexing (OFDM) bandwidths up to 100 MHz. Enhanced reconfigurability is demonstrated with non-contiguous carrier aggregation and digital carrier generation between 1.5 and 1.9 GHz without a frequency synthesizer. For a 20-MHz 256-QAM OFDM signal at 3.5% error vector magnitude (EVM), the transmitter achieves 22.6-dBm output power and 14.6% PA efficiency. Thanks to the high linearity enabled by tri-phasing, no digital predistortion is needed for the PA.
Year
DOI
Venue
2019
10.1109/JSSC.2019.2902753
IEEE Journal of Solid-State Circuits
Keywords
Field
DocType
Radio frequency,Phase modulation,Radio transmitters,Bandwidth,Linearity
RF front end,Computer science,Radio transmitter design,Electronic engineering,Frequency synthesizer,Modulation,Amplitude modulation,Predistortion,Orthogonal frequency-division multiplexing,Amplifier
Journal
Volume
Issue
ISSN
54
6
0018-9200
Citations 
PageRank 
References 
1
0.36
0
Authors
10
Name
Order
Citations
PageRank
Jerry Lemberg162.96
Mikko Martelius232.14
Enrico Roverato3124.20
Yury Antonov422.45
Tero Nieminen552.24
Kari Stadius66823.73
Lauri Anttila774561.19
Mikko Valkama81567175.51
Marko Kosunen95118.09
Jussi Ryynänen105719.17