5G and InP HBT MMIC technology – the Prospects and Opportunities at mm-Wave
The superior electron transport properties associated with the InP-based transistors significantly exceeds those of its SiGe HBT, CMOS, and GaN counterparts. Since 2000, the transistor and MMIC community has witnessed the bandwidths of InP HBTs and HEMTs skyrocket past 100-GHz to where they now exceed 1-THz operation. With this rapid increase in bandwidth, amplifiers and MMICs were designed for similarly higher bandwidth and operate at G-band, sub-millimeter wave (>300-GHz), and THz frequencies where a world-class suite of results has been generated and are well known to high-frequency community. However, only recently have these THz devices been used for amplifier and MMIC development at lower Ka-, Q-, E-, and W-band frequencies, where state-of-the-art performance has been demonstrated as well. This InP-transistor technology advancement is very different than what has transpired for SiGe HBT, CMOS, and GaN – instead, these technologies have incrementally increased their bandwidths, and in doing so, so have the circuits employing such devices – this is a key reason why InP is overshadowed by these other technologies when amplifiers and MMICs operating below 100-GHz are discussed and reviewed.
With the emergence of 5G and its proposed frequency standards exceeding 28-GHz, it is assumed that SiGe, CMOS, and GaN will be the technologies of choice – before this becomes a foregone conclusion, it would be wise to examine InP more closely and identify its potential contribution to 5G. With that background, the objective of this talk will be to present the current state-of-the-art for InP HBT based amplifiers and MMICs covering Ka-band up to G-band. The different HBT technology scaling nodes will be reviewed to understand tradeoffs between bandwidth and voltage breakdown, as well as amplifier topologies that have been employed. Lastly, some discussion will be included to address the InP technology cost and challenges associated with mass production related to 5G.