25.2 A 19.7-to-43.8GHz Power Amplifier with Broadband Linearization Technique in 28nm Bulk CMOS

5G mm-wave systems in the frequency-range-2 (FR2) band (ranging from 24.25 to 43.5GHz) are expected to provide multi-gigabit-per-second (mGb/s) data-rates. Different FR2 bands are employed to build 5G wireless networks in different countries/regions around the world. Thus, a broadband/multiband 5G mm-wave systems are expected to economically support 5G international/cross network roaming. To overcome the high free-space path loss (FSPL), phased arrays integrating a large number of transmit/receive channels are adopted, which require a large on-chip area and lead to high cost [1], [2]. Moreover, spectrum-efficient modulations with a high peak-to-average power ratio (PAPR) and a large RF bandwidth, such as high-order QAM are employed in 5G systems to enable mGb/s-link throughput revolution [3], [4]. These requirements call for compact, broadband, high-linearity, high-efficiency PAs to cover multiple 5G bands. Thus, this paper presents a 19.7 to 43.8GHz broadband ultra-compact linear PA.