Mitsubishi Electric has developed a new technology to realize a GaN power amplifier module for 5G base-stations that offers a combination of compact (6 mm x 10 mm) footprint and extra high power efficiency, according to Mitsubishi Electric research as of July 14, 2020, the latter exceeding an unprecedented rating of 43 percent, using the 5G frequency range of 3.4 to 3.8 GHz. The module, which uses a minimum number of chip components in the matching circuit to control high-quality signal output, is expected to help realize 5G base-stations that are widely deployable and highly power efficient. Technical details of the new module will be presented during the IEEE International Microwave Symposium Technical Session (session ID: We2G-3) this coming August.

Key Features

1) High density mounting technology to realize compact (6 mmx10 mm) power amplifier module for more widely deployable 5G base-stations

o    In 4G base-stations, which do not usemMIMO antennas, power amplifiers use metal-foil transmission lines for the matching circuit. While this lowers power loss, resulting in high efficiency operation, transmission lines take up space and make it difficult to realize base stations that are both extra small and extra power efficient. Mitsubishi Electric's new technology eliminates the need for transmission lines in 5G power amplifiers.
o    The new amplifier module's matching circuit is integrated with surface mount devices (SMDs), such as capacitors and inductors. By introducing a highly accurate electromagnetic field analysis method and applying a unique technology for the dense arrangement of SMDs, Mitsubishi Electric was able to reduce the amplifier's size to just one-ninetieth that of conventional power amplifiers, Mitsubishi Electric's 4G power amplifiers released on January 12, 2017.

2) World's highest power efficiency reduces 5G base-station's power consumption

o    High efficiency GaN transistors help to increase the efficiency of the power amplifier.
o    Using SMDs for the matching circuit can reduce the amplifier's size but also can decrease power efficiency because SMDs tend to have high power loss. Mitsubishi Electric's new technology, however, creates a matching circuit using a small number of SMDs. Furthermore, the SMDs offer the same electrical characteristics as those of metal-foil transmission lines. The resulting power amplifier module achieves a leading power efficiency rating of more than 43 percent in the 3.4 to 3.8 GHz bands used for 5G communications.