By Paul A. Moakes, CommAgility
Looking at 5G’s technical challenges, we see the frequencies and spectrum supported now include a sub-6 GHz range, FR1, with bandwidths up to 100 MHz as well as a mmWave band, FR2, with bandwidths up to 400 MHz. This requires high bandwidth transceivers, resulting in interfaces such as JESD204 becoming faster and more expensive in power [Ref. 1]. A more integrated platform becomes preferable.
To meet the higher RF power demands and increased crest factor of 5G, IC designers are turning to more efficient technologies such as Gallium Arsenide for the RF power amplifiers (PAs). This amplifier class has highly non-linear characteristics with a memory effect, meaning that digital pre-distortion (DPD) techniques are required to maintain signal integrity. At higher bandwidths, the digital front end (DFE) that handles DPD requires a proportionate increase in processing performance.