GaN-on-SiC Transistor for 2.45GHz RF Surpasses Efficiency of Most Magnetrons

June 05, 2019 by Scott McMahan

NXP Semiconductors N.V. announced what the company claims to be the first RF power transistor using GaN-on-SiC. Taking advantage of GaN's high efficiency, the MRF24G300HS exceeds the efficiency of most magnetrons at 2.45GHz, and the high thermal conductivity of SiC helps to ensure continuous wave operations. (See image above of NI-780S-4L package).

The 300W CW GaN transistors, MRF24G300HS is designed for industrial, scientific and medical (ISM) applications at 2450MHz. This device is suitable for use in CW, pulse, cycling, and linear applications. According to NXP, this high gain and high-efficiency device can replace industrial magnetrons and will provide longer life and ease of use. Target applications for the GaN-on-SiC transistors include industrial heating, welding and heat sealing, plasma generation, lighting, and scientific instrumentation, as well as medical applications such as microwave ablation and diathermy.

For more than 50 years, 2.45GHz magnetrons have been widely adopted in consumer and industrial applications ranging from microwave ovens to high power welding machines. Solid-state solutions emerged several years ago, bringing advanced control, reliability, and ease of use.

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The ability to dynamically adjust the power, frequency, and phase can help optimize the energy transmitted to the material or food being heated. The long lifetime of transistors at full rated performance reduces the need for replacements.

However, until the appearance of GaN-on-SiC for RF energy, solid-state devices lacked the efficiency needed to meet the performance standards of incumbent magnetrons.

The GaN-on-SiC transistor demonstrates 73% drain efficiency at 2.45GHz, which, according to NXP, is five points higher than the latest LDMOS technologies. The high power density of GaN enables the device to reach high output power in a small footprint.

GaN technology offers an inherently high output impedance that allows broadband matching compared to LDMOS. This matching reduces the design time and ensures consistency on the manufacturing line. So no more hand tuning is needed.

Also, the simplified gate biasing of the MRF24G300HS RF transistor eliminates another step of the otherwise complex power-up sequence that is typical of GaN devices.

This component is characterized and NXP guarantees its performance for applications operating in the 2400MHz to 2500MHz band.

However, the company does not guarantee the performance of the component when it is used in applications designed outside of these frequencies.

"The smart control, low maintenance, and ease of use of solid-state open the door to new use cases, such as smart cooking and industry 4.0 heating machines," said Paul Hart, senior vice president and general manager of NXP's Radio Power Solutions. "By breaking the efficiency barrier of vacuum tubes, we enable our customers to unlock innovation without any compromise on performance."


  • Advanced GaN-on-SiC, for optimal thermal performance
  • Characterized for CW, long pulse (up to several seconds) and short pulse operations
  • Device can be used in a single-ended or push-pull configuration
  • Input matched for simplified input circuitry
  • Qualified up to 55V
  • Suitable for linear application
  • RoHS Compliant


NXP's MRF24G300HS RF transistor is sampling now and production is scheduled for Q3 2019. The 2400MHz to 2500MHz reference circuit is available now, under order number MRF24G300HS-2450MHZ. As part of the NXP Partner Program, Prescient Wireless, Inc. designed a 2-up, 550W power amplifier pallet with 45 dB of gain.