Design considerations for 5G mm-wave receivers

Abstract

To meet yet higher speed and capacity demands, 5G will turn to mm-waves for more bandwidth. In this paper some receiver design issues occurring when moving from current 4G bands to mm-wave frequencies are discussed. The local oscillator phase noise increases by 6dB/octave with frequency and will ultimately limit spectrum efficiency. To analyze this, a phase noise model, based on a test chip designed in 28 nm FD-SOI, is presented. Provided is also a thorough analysis on the wideband receiver noise figure evolution that shows an expected noise figure increase from 5.1 dB to 9.1 dB when shifting from 2 GHz to 30 GHz carriers. By taking advantage of the anticipated improvements from CMOS scaling, it is shown that 10 years from now, the receiver noise figure will improve to 7.7 dB at 30 GHz. The presented mm-wave integration aspects also account for beamforming and array antennas, and how this relates to building practice, power consumption and area.