Frequency Reconfigurable Dual-Band CMOS Power Amplifier for Millimeter-Wave 5G Communications

A frequency reconfigurable dual-band power amplifier (PA) with reconfigurable transmission line transformers (TLT) is presented, which can be operated at both the n257 (26.5-29.5 GHz) and n260 (37–40 GHz) 5G communication bands. The PA utilizes reconfigurable TLTs for output and input matching networks to reconfigure the PA between the n257 and n260 bands with optimal performance in both bands. The reconfigurable TLTs provide frequency reconfigurability to the PA by changing both the primary and secondary side inductances of the TLTs. The switches for the TLTs are located in the space inside the TLTs, which results in a small overall chip area. The dual-band PA is fabricated using a 28-nm bulk CMOS process. It achieves 20.2 and 19.1 dBm saturated output powers, 18.7 and 18.6 dBm 1-dB compressed output powers and 33.6% and 32% peak power added efficiencies at 26.5 and 37 GHz, respectively. The dual-band PA has a core size of 0.11 mm ² .