A 3.5-GHz THREE-STAGE DOHERTY POWER AMPLIFIER WITH BIAS CONTROLLER USING POWER TRACKING METHOD

作者：Lee Mun Woo; Kam Sang Ho; Jeong Yoon Ha^*

来源：Microwave and Optical Technology Letters, 2012, 54(1): 23-26.

DOI：10.1002/mop.26474

• Doherty power amplifier
• efficiency
• driving amplifier
• GaN HEMT
• power tracking

This letter represents a three-stage Doherty power amplifier with a bias controller. The driving amplifier controls the input power of the carrier cell to eliminate the gate current of the carrier cell at high input power levels. The gate bias voltage of the driving amplifier is controlled by a power tracking method according to input power levels. For verifications, the driving amplifier, carrier, and peaking cells are fabricated using 10-W, 15-W, 35-W gallium nitride high electron mobility transistors, respectively, at 3.5 GHz. From a continuous wave, the power-added efficiencies (PAEs) of 34.4 and 39.6% are achieved at similar to 9.5-and 4.3-dB back-off powers, respectively. For a worldwide interoperability for microwave access signal, the proposed DPA has the PAE of 37.1 % at an output power of 41.5 dBm.

• 出版日期2012-1