My Gallium Nitride (GaN) is fully on the scene and in the market, but Gallium Arsenide (GaAs) is still being used. Why is the old technology still in use? One is the present and foreseable future of high-power RF, while the other remains indispensable in sensitive front-end designs. The reality is that both GaN and GaAs are shaping radar, electronic warfare (EW), and communications systems in complementary ways.
Why GaN is the Game-Changer
Over the past decade, GaN technology has become the cornerstone of next-generation radar and EW systems. Its advantages stem from the physics of the material itself:
- Wide Bandgap Performance: GaN can handle higher voltages and power densities than silicon or GaAs.
- High Power Density: More watts per square millimeter translate directly into smaller, lighter, and more powerful transmitters.
- Thermal Efficiency: GaN devices run cooler at equivalent power levels, reducing the burden on bulky cooling systems.
These strengths make GaN ideal for active electronically scanned array (AESA) radars, high-power jammers, and SATCOM uplinks. Modern radar platforms rely on GaN transmit/receive modules to deliver long-range detection and simultaneous electronic attack. In short, GaN is enabling defense systems to see farther, react faster, and pack more power into smaller footprints.
Why GaAs Is Still Around
With GaN’s rise, you might expect GaAs to fade into history. Yet, it continues to be a workhorse technology across the defense spectrum. Why?
- Unmatched Low Noise
- GaAs still delivers a superior noise figure, making it the preferred material for low-noise amplifiers (LNAs) in radar receivers, SIGINT, and ELINT systems.
- GaAs still delivers a superior noise figure, making it the preferred material for low-noise amplifiers (LNAs) in radar receivers, SIGINT, and ELINT systems.
- Mature and Cost-Effective
- GaAs fabrication processes are stable, reliable, and cost-efficient.
- For certain device classes, it is more economical than GaN.
- Legacy Sustainment
- Countless deployed systems were built around GaAs.
- Sustainment, repair, and reverse engineering efforts still depend on keeping GaAs devices available.
- Ease of Integration
- Design libraries, models, and long-term supply chains make GaAs straightforward for RFIC and MMIC development in applications that don’t require GaN’s extreme power density.
- Design libraries, models, and long-term supply chains make GaAs straightforward for RFIC and MMIC development in applications that don’t require GaN’s extreme power density.
In fact, most modern defense systems combine GaN and GaAs: GaN in the transmit chain for raw power, and GaAs in the receive chain where sensitivity is paramount.
The Tradeoffs Engineers Face
Every defense RF engineer knows that material choice is rarely “one size fits all.”
- GaN excels in power amplifiers, transmit modules, and high-voltage environments.
- GaAs excels in ultra-sensitive front ends and cost-sensitive designs.
The result is hybrid architectures that balance performance with efficiency, noise, and budget constraints.
Industry and Market Perspectives
The U.S. Department of Defense continues to invest heavily in GaN foundry capabilities through DARPA, the Navy, and the Air Force. Commercial markets like 5G and satellite communications are also accelerating GaN adoption.
Yet GaAs remains a trusted workhorse, with its own foundry ecosystem, mature tooling, and global supply chain. Defense primes often pursue hybrid integrated microwave assemblies that blend both materials—because in practice, systems need both high power and low noise.
So, will GaN replace GaAs?
Not quite. GaN is redefining what’s possible in high-power defense applications, but GaAs remains unmatched in low-noise performance and cost efficiency.
For the foreseeable future, expect radar, EW, and communications systems to be hybrid by design—leveraging GaN where brute force is needed and GaAs where precision and sensitivity are critical.
We see this duality every day—whether sustaining legacy GaAs-based systems, integrating GaN upgrades, or developing test solutions that ensure both technologies continue to serve the warfighter.
References
- Cripps, S. C. GaN, GaAs, and LDMOS: A Secure Place for All. High Frequency Electronics.
- MSE Supplies. What are the Differences Between GaN and GaAs RF Power Amplifiers? (2023).
- Military Embedded Systems. The Benefits and Challenges of Using GaN Technology in AESA Radar Systems (2020).
- Power Electronics News. Benefits of GaN for RF Applications (2021).
- Wikipedia. Gallium Nitride and Gallium Arsenide.
- Qorvo. A Primer on GaN and 3 Reasons It Outperforms Other Semiconductors in RF Applications (2022).
- Wikipedia. Uttam AESA Radar.
- Qorvo. X-Band Radar: Driving Defense Applications with Beamforming GaN and GaAs Technology (2022).
