A 3.3V broadband linear power amplifier module for IEEE 802.16e (Wimax) applications using E-mode pHEMT technology

This paper describes, for the first time, the design and realization of a linear power amplifier for the newly-ratified IEEE 802.16e WMAN (WiMax) applications using a proprietary 0.25 um enhancement-mode pHEMT (EpHEMT) technology. When tested using a 10MHz bandwidth IEEE802.16e signal with 64-QAM modulation, the amplifier exhibits a linear power output of (22.5-23)dBm across the full (3.3-3.8)GHz band with less than 2.5% EVM on a single 3.3V supply while consuming 420 mA of total current. A 20 dB bypass gain attenuator that is activated by a CMOS-compatible voltage pin is included on-chip. Output power detection is achieved by the use of an on-chip power detector and a bias shutdown voltage shuts down the complete amplifier. At 3.6 V supply tuned to (3.3-3.6)GHz operation, the amplifier outputs 24 dBm of linear output power. The complete module is packaged in a molded chip-on-board (MCOB) 5 mm times 5 mm module.