A Multi-Band CMOS Power Amplifier Using Reconfigurable Adaptive Power Cell Technique

A reconfigurable adaptive power cell configuration for a multi-band CMOS power amplifier (PA) is presented, for long-range WLAN applications. The common gate (CG) transistor of a CMOS cascode power cell consists of four differently biased 4-transistor cells to have good linearity, two of which are subsidiary cells and are turned off to cover the higher frequency band. This allows the PA to operate in multi-band properly without any additional switches or paths for multi-band. The chip is fabricated in 40 nm CMOS technology, and its size including the ESD-protected pad is 1.985 × 1.61 mm
²
. The measurement results show that the proposed PA achieves the output power of 27.8 (28.2) dBm with the PAE of 52% (53%) at a high (low) frequency band.