A 150–175-GHz 30-dB S ₂₁ Power Amplifier With 125-mW P _out and 16.2% PAE Using InP HBT

High-Efficiency 200-GHz Neutralized Common-Base Power Amplifiers in 250-nm InP HBT

“…Transistor configurations have a dramatic impact on performance above 100 GHz due to the role of parasitics. In general, higher gain is desired for compensating input matching losses of PA. Common-emitter (CE) is commonly selected for CMOS and SiGe PA designs in millimeter-wave bands [14] but CB [12] is also a candidate for the InP HBT process due to the relatively small base-collector capacitance.…”

“…PA designs in SiGe HBT processes have shown decent power gain with multi-stage design and high output power with power combining at lower G-band range [8], [9] but the efficiency is limited to single digits above 200 GHz [10], [11]. Compared to the SiGe HBT, the 250-nm InP HBT process has superior collector-emitter voltage breakdown, higher f max for G-band PAs, and higher output power with higher small-signal gain across 140-220 GHz [12], [13], [14], [15], [16], [17]. InP HEMT or GaN HEMT are processes that can achieve high f T /f max but PA performance at G-band is still not competitive compared to SiGe or InP HBT due to increased loadline matching conditions [18], [19], [20].…”