A 190-210GHz Power Amplifier with 17.7-18.5dBm Output Power and 6.9-8.5% PAE

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

“…The large signal discrepancy is most likely due to self-heating that is not incorporated into HBT devices model. Similar discrepancy is also observed in [12].…”

“…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.…”

“…1, CB does not offer unconditional stability across G-band and requires additional stabilization circuitry. In [12], the authors leverage the sizing of base capacitance to linearize and stabilize CB stages as shown in Fig. 2(a).…”

“…Finite base capacitance is designed in [12] without revealing the design consideration or parameters. To understand the reasonable design parameters, simulation of stability factor and With the insight for determining Q at the base, the sweep of capacitance for 140, 180, and 220 GHz is shown in Fig.…”

“…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].…”