The Need

In an era of rapid growth in modern communication, there is an increasing demand for multi-band and broadband power amplifiers (PA) for signals with large peak-to-average power ratio (PAPR). The PA, being one of the most power-consuming components in a transmitter system, needs to achieve high average power efficiency for signals with large PAPR.

The conventional Doherty power amplifier faces significant challenges to achieve high average efficiency. In recent years, efforts have been made to improve the average efficiency to meet the needed high average efficiency.

The Technology

Dr. Patrick Roblin, along with other researchers at The Ohio State University have developed a new architecture and design methodology for a new multi-band Doherty power amplifier (DPA) designed for applications such as cellular phone base stations. This dual-band Doherty power amplifier (DB-DPA) is based on a 3-way architecture and includes a main amplifier for each band and an auxiliary amplifier handling both bands. The 3-Way DB-DPA improves the average drain efficiency in concurrent dual-band operation compared to the traditional 2-Way DB-DPA. It avoids early clipping in the main amplifiers while benefiting from load-pulling from the auxiliary power amplifier.

Commercial Applications

• Cellular phone base stations
• Broadband communication systems
• Multi-band transmitter systems

Benefits/Advantages

• Improved average drain efficiency in concurrent dual-band operation
• Avoidance of early clipping in the main amplifiers
• Beneficial load-pulling from the auxiliary power amplifier
• Efficient use of spectrum for increasing data rate
• High average power efficiency for signals with large PAPR