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ICT – MILLIMETRE WAVE TECHNOLOGY

If 3 dB EIRP improvement is achieved Conclusion
by applying the DPD, the number of DPD implementation in 5G mmWave arrays brings new challenges relative to sub-6 GHz
required elements is reduced by almost frequencies. Wrapping a DPD loop around the beam, as opposed to individual PAs that
30% and the power dissipation drops form a beam, makes array DPD feasible and beneficial. Our analysis has shown that
by about 20%. Compared to our sub-6 there are tangible benefits in terms of higher output powers, system power saving
GHz example, where applying the DPD and hardware reduction. We would, however, urge caution: mmWave DPD in both its
reduces the power consumption of application and its evaluation needs to be viewed through a different perspective than
the PAs by a factor of 4, the power that of legacy sub-6 GHz. As mmWave PA architectures mature, that positioning may
savings in the mmWave array is not shift, but for now we need to reinvent the application of DPD as well as our positioning
as significant. However, in the case on the benefits. n
of mmWave, we get an additional
dividend in that the 30% reduction in References
the number of elements represents a - 38.104: Base Station (BS) Radio Transmission and Reception. 3GPP, March 2017.
1
considerable saving in the cost and size - Delos, Peter, Bob Broughton, and Jon Kraft. “Phased Array Antenna Patterns—Part 1: Linear
of the array hardware. In the future, it Beam Array Characteristics and Array Factor.” Analog Dialogue, Vol. 54, No. 2, May 2020.
will be possible to use more efficient PA - Delos, Peter, Bob Broughton, and Jon Kraft. “Phased Array Antenna Patterns—Part 2:
architectures in mmWave beam formers Grating Lobes and Beam Squint.” Analog Dialogue, Vol. 54, No. 2, June 2020.
to further improve the power efficiency - Delos, Peter, Bob Broughton, and Jon Kraft. “Phased Array Antenna Patterns—Part 3:
with DPD. Sidelobes and Tapering.” Analog Dialogue, Vol. 54, No. 3, July 2020.

About the authors
Hossein Yektaii began his career at Analog Devices in November 2016. Before joining ADI, he worked at Nortel, Alcatel-Lucent, and
Nokia, where he held different positions ranging from RF design engineer to radio system designer. In his current role as a wireless
system architect, he leverages his end-to-end radio system knowledge to better understand customer requirements and shape the
architecture and specifications of increasingly sophisticated ADI solutions in the wireless market. He studied electrical engineering at
Sharif University of Technology and received his master’s degree in telecommunications from Tehran University. He can be reached at
hossein.yektaii@analog.com.

Patrick Pratt is a senior research scientist in the communication system team of Analog Devices. His career spans over 30 years and
encompasses algorithm research and development activity, both in private organisations and academic institutions. Patrick holds a Ph.D.
in electronic engineering from Cork Institute of Technology. He can be reached at patrick.pratt@analog.com.

Frank Kearney joined Analog Devices after graduating in 1988. During his time with the company, he has held a diversity of engineering
and management roles. He currently manages a team of architects and algorithm developers in the wireless systems group. The
group’s focus is on transmit path efficiency and system level enhancements for O-RAN radio architectures. Frank holds a doctorate from
University College Dublin. He can be reached at frank.kearney@analog.com.

Hossein Yektaii Patrick Pratt Frank Kearney

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