TY - GEN
T1 - A 30GHz 4-way Series Doherty Digital Polar Transmitter Achieving 18% Drain Efficiency and-27.6dB EVM while Transmitting 300MHz 64-QAM OFDM Signal
AU - Mortazavi, Mohsen
AU - Shen, Yiyu
AU - Mul, Dieuwert P.N.
AU - De Vreede, Leo C.N.
AU - Spirito, Marco
AU - Babaie, Masoud
PY - 2021
Y1 - 2021
N2 - Fifth-generation (5G) mm-wave communication systems support high-order modulation schemes with large peak-to-average power ratios (PAPR). This demands transmitter (TX) operation in deep power back-off (PBO), thus degrading its average efficiency. Hence, several mm-wave Doherty PAs have been proposed [1], [3] to address this issue. However, the number of their peaking amplifiers (PAP) has been limited to two, mainly due to poor scalability, and high losses in the Doherty power combiner. Therefore, the efficiency enhancement was restricted to the 10dB PBO range. Furthermore, prior-art chiefly employed an analog class-AB amplifier for the main PA (PAM), degrading the system efficiency (SE) for two reasons. First, the conduction angle of an analog amplifier increases with a reduction of the drive signal amplitude, resulting in a Class-A-type efficiency roll-off that severely degrades the achievable PBO efficiency. Second, the output impedance of analog PAs is almost constant while the PAs' load significantly increases in PBO Doherty operation. This results in a load mismatch at PBO, degrading the PAs' gain and efficiency while giving rise to AM-AM and AM-PM distortion.
AB - Fifth-generation (5G) mm-wave communication systems support high-order modulation schemes with large peak-to-average power ratios (PAPR). This demands transmitter (TX) operation in deep power back-off (PBO), thus degrading its average efficiency. Hence, several mm-wave Doherty PAs have been proposed [1], [3] to address this issue. However, the number of their peaking amplifiers (PAP) has been limited to two, mainly due to poor scalability, and high losses in the Doherty power combiner. Therefore, the efficiency enhancement was restricted to the 10dB PBO range. Furthermore, prior-art chiefly employed an analog class-AB amplifier for the main PA (PAM), degrading the system efficiency (SE) for two reasons. First, the conduction angle of an analog amplifier increases with a reduction of the drive signal amplitude, resulting in a Class-A-type efficiency roll-off that severely degrades the achievable PBO efficiency. Second, the output impedance of analog PAs is almost constant while the PAs' load significantly increases in PBO Doherty operation. This results in a load mismatch at PBO, degrading the PAs' gain and efficiency while giving rise to AM-AM and AM-PM distortion.
UR - http://www.scopus.com/inward/record.url?scp=85107223152&partnerID=8YFLogxK
U2 - 10.1109/CICC51472.2021.9431396
DO - 10.1109/CICC51472.2021.9431396
M3 - Conference contribution
AN - SCOPUS:85107223152
T3 - Proceedings of the Custom Integrated Circuits Conference
BT - 2021 IEEE Custom Integrated Circuits Conference, CICC 2021 - Proceedings
PB - Institute of Electrical and Electronics Engineers (IEEE)
T2 - 2021 IEEE Custom Integrated Circuits Conference, CICC 2021
Y2 - 25 April 2021 through 30 April 2021
ER -