A 0.4-1.2 GHz Reconfigurable CMOS Power Amplifier for 802.11ah/af Applications

A reconfigurable broadband linear power amplifier (PA) for long-range WLAN applications fabricated in a 180 nm RF CMOS process is presented here. The proposed reconfigurable in/output matching network provides the PA with broadband capability at the two center frequencies of 0.5 GHz and 0.85 GHz. The output matching network is realized by a switchable transformer which shows maximum peak passive efficiencies of 65.03% and 73.45% at 0.45 GHz and 0.725 GHz, respectively. With continuous wave sources, a 1-dB bandwidth (BW1-dB) according to saturated output power is 0.4-1.2 GHz, where it shows a minimum output power with a power added efficiency (PAE) of 25.62 dBm at 19.65%. Using an adaptive power cell configuration at the common gate transistor, the measured PA under LTE 16-QAM 20MHz (40 MHz) signals shows an average output power with a PAE exceeding 20.22 (20.15) dBm with 7.42 (7.35)% at an ACLR(E-UTRA) of -30 dBc, within the BW1-dB.