A 28/38 GHz Dual-Band Power Amplifier for 5G Communication

This work presents a 28/38 GHz dual-band power amplifier (PA) for fifth-generation (5G) communication. In this work, a T-topology-matching network is proposed at the output for its dual-band operation and low insertion loss. Also, a modified dual-LC tank-matching method is proposed for the input and interstage part due to its wideband performance and large-impedance transformation capability. This modified dual-LC tank boosts the transformation ratio to 30 at the interstage matching without trading bandwidth for the 28/38 GHz operation. Furthermore, circular inductors are applied to the matching networks for low insertion loss. This design is fabricated in a 0.25-μm SiGe:C BiCMOS technology with a core area of 300 × 770 μm2. In combination with the proposed methods, this PA achieves 28/38 GHz dual-band operation with high power-added efficiency (PAE). At 28 GHz, the measured peak power-added efficiency (PAEpeak) is 25%, the saturated output power (Psat) is 18.8 dBm, and 1-dB compressed power (P1 dB) is 17.8 dBm. At 38 GHz, those are 17.5%, 17 dBm, and 15.8 dBm, respectively.