High-performance GaN power transistors target wireless basestations

February 22, 2016 // By Jean-Pierre Joosting
M/A-COM Technology Solutions has announced its highly-anticipated MAGb series of GaN power transistors for use in wireless macro basestations, boasting the ability to displace LDMOS in cellular bands between 1.8 to 3.8 GHz.

Leveraging MACOM’s Gen4 GaN technology, the MAGb series claims to be the industry’s first commercial basestation-optimized family of GaN transistors to achieve leadership efficiency, bandwidth and power gain with a linearity and cost structure like LDMOS, and a path to better than LDMOS cost at scaled volume production levels.

The MAGb series of power transistors target all cellular bands within the 1.8 GHz to 3.8 GHz frequency range. Initial entries in the product series include single-ended transistors providing up to 400 W peak power in small packages, dual-transistors and single-package Doherty configuration providing up to 700 W peak power in both symmetric and asymmetric power options. This product series delivers power efficiency improvement of up to 10% and package size reduction greater than 15% over legacy LDMOS offerings. Based on linear Gen 4 technology, the MAGb is easy to linearize and correct with digital-pre-distortion (DPD) schemes compared to other GaN technologies.

The power transistors in the MAGb family cover much wider bandwidth than LDMOS, reducing the number of parts needed to cover the major cellular bands. The product family delivers these advantages while simplifying the Doherty implementation over LDMOS-based transistors and maintaining over 200 MHz of video bandwidth. The MAGB-101822-120B0S is the first product in this family and covers 500 MHz of RF bandwidth between 1.7 GHz to 2.2 GHz. It is housed in a small AC-400 ceramic package and delivers over 160 W of peak power and a peak efficiency of 74% with fundamental tuning only and linear gain over 19 dB across the 500 MHz band.

Second in this series is the MAGB-101822-240B0S, which has double the output power of the MAGB-101822-120B0S with peak power over 320 W, 19 dB of linear gain and peak efficiency over 72% with fundamental tuning only across the 500 MHz RF bandwidth, housed in the AC-780 ceramic package. The peak efficiency of both parts can be further improved to well above 80% when the devices are presented with the proper harmonic terminations.

The MAGb series compliments MACOM's expanded portfolio of wireless infrastructure products.