MaxLinear, Cree partner on 5G power amplifiers

MaxLinear, Inc. and Cree, Inc. through its Wolfspeed business, claimed breakthrough performance when combining MaxLinear’s ultra-wideband linearization solution (MaxLin) and Cree’s Wolfspeed gallium nitride (GaN) on silicon carbide (SiC) mid-band power amplifiers. The new solution increases wireless capacity of a 5G base station to support more simultaneous users and higher speed of data transmissions.

The use of GaN on SiC with effective linearization accelerates the rollout of 5G by enabling significant power, thermal, and cost savings through more efficient wireless transmission, said the companies. They estimate the power savings can be hundreds of watts for massive MIMO radios.

The new solution targets a big challenge, implementing radio units with 5G massive MIMO arrays such as 64×64 or 32×32, without increasing cost, power, and size. What makes it more of a challenge to achieve higher power efficiency for the radio units is that the newer 5G spectrum has a higher carrier frequency and wider bandwidths.

“High power efficiency for radio units is more difficult to achieve because the newer 5G spectrum is at a higher carrier frequency, in addition to wider bandwidths,” said Gerhard Wolf, senior vice president and general manager of RF at Cree.

“Compared to other solutions, GaN on SiC has several advantages, including better thermal conductivity, increased efficiency at higher frequencies and higher power density to meet demands of 5G,” he added. “In addition, the power per device and achieved efficiency can be much higher compared to traditional technologies.”

Cree’s GaN on SiC power amplifiers are designed to achieve high efficiency in a small form factor, while MaxLinear’s wideband, power-efficient linearization solution combined with its low-power 400-MHz transceivers reduce the heat dissipated by massive MIMO arrays.

Thus, by using GaN on SiC, MaxLinear’s solution, is said to deliver breakthrough linearization performance for a 280-MHz channel to support U.S. 5G spectrum (3.7-3.98 GHz) and a 400-MHz channel to support Asian and European 5G mid-band spectrum (3.4-3.8 GHz). At 280 MHz of instantaneous bandwidth, Cree’s WS1A3940 power amplifier achieves about 50% efficiency for the average output power of 39.5 dBm, MaxLinear’s MxL1600 transceiver provides a sampling rate of 983 MSPS, and MaxLin improves linearity by >20 dB to exceed 3rd Generation Partnership Project (3GPP) and Federal Communications Commission (FCC) requirements with margin, according to the companies.

In addition, using the Wolfspeed WS1A3640 power amplifier, MaxLin also demonstrates a >20 dB linearization improvement at 400 MHz of instantaneous bandwidth.

Cree’s WS1A3940 and WS1A3640 GaN on SiC power amplifier modules, MaxLinear’s MxL15xx and MxL16xx 400MHz transceivers, and MaxLinear’s MaxLin linearization technology can be used for both traditional and Open RAN applications.