For decades, defence and aerospace programmes relied on travelling wave tube amplifiers and silicon LDMOS devices to push signals out of radar arrays, satellite uplinks and electronic warfare systems. Both technologies served their purpose, but neither was designed for the frequency, power density and reliability envelope that modern mission systems now demand. Gallium nitride has changed that equation, and across the programmes we support in Singapore and the wider Asia-Pacific, GaN RF power amplifiers have quietly become the default specification for new builds.
This guide breaks down what makes GaN technology RF different, where it fits, and what engineers and procurement teams should look for when specifying components for defence-grade builds.
A gallium nitride amplifier behaves differently from its silicon and GaAs predecessors because the material itself is different. GaN is a wide-bandgap semiconductor with a breakdown field substantially higher than silicon, which allows the device to handle far higher voltages in a smaller die. The result is more output power per square millimetre, which is why we see customers replacing legacy GaAs modules with GaN whenever a refresh cycle comes around.
Three practical advantages follow from this:
Higher power density. GaN-on-SiC transistors deliver significantly more RF power per unit area than GaAs, which means smaller modules, lighter payloads and easier integration into space-constrained platforms like UAVs and active electronically scanned array (AESA) radars.
Better thermal performance. Silicon carbide substrates conduct heat efficiently, so high-power RF amplifier designs can run harder without throttling. This matters for pulsed radar and continuous-wave satcom applications where thermal headroom defines mission duty cycles.
Wide bandwidth at high frequency. GaN devices operate cleanly from sub-1 GHz up through Ka-band and beyond, supporting multi-octave designs that older technologies simply cannot match.
In defence and aerospace, the application list is long and growing. Active phased array radars use many small GaN modules instead of one large tube transmitter, improving reliability through graceful degradation. Electronic warfare jammers take advantage of GaN’s wideband behaviour to cover threat bands without swapping hardware. Satellite ground terminals and onboard transponders use GaN solid-state power amplifiers (SSPAs) as a lighter, more efficient alternative to TWT amplifiers. Even avionics datalinks and tactical radios increasingly specify GaN front ends for their size, weight and power (SWaP) benefits.
For Singapore-based integrators serving regional defence and avionics programmes, the harder part is usually not picking the right device, it is sourcing it. Components must meet AS9120B traceability, ITAR or EU dual-use export requirements, and lead times that match programme schedules. From what we have seen across thirty years of supporting the region, working with a certified RF distributor matters as much as the device specification itself, and our leading-edge GaAs and GaN technologies portfolio is built around exactly that need, covering distributed amplifiers, low-noise amplifiers, driver stages and X-band power MMICs from Altum RF.
Specifying a GaN device is more than checking the output power figure on a datasheet. A few parameters deserve careful attention.
Frequency range and gain flatness. Wideband designs like the Altum RF ARF1300Q4 distributed amplifier offer 13 dB of linear gain across very broad bands, useful for instrumentation and EW. Narrowband X-band parts like the ARF1001C7 trade bandwidth for higher saturated output, hitting 37 dBm in a compact ceramic package. We see both styles requested regularly, and the right pick almost always comes down to how the customer plans to operate the chain rather than headline specs.
P1dB and saturated output power. P1dB tells you where linearity begins to fail. For high-order modulation schemes used in modern satcom, you generally want to back off well below saturation to preserve EVM.
Power-added efficiency. PAE drives thermal design and DC power budgets. Modern GaN-on-SiC devices deliver strong PAE figures, but this varies sharply with frequency and back-off, so always read the curves rather than the headline number.
Bias and matching. Many Altum RF amplifiers are internally matched to 50 Ω with ESD protection and require a bias tee on the RF output. Properly selected GaN drivers ahead of the final stage make a measurable difference to overall linearity and system noise figure, a detail that catches out teams designing their first GaN chain.
Compliance and packaging. RoHS compliance, air-cavity ceramic packaging for harsh environments, and dual-use export documentation should all be confirmed before procurement.
GaN is no longer exotic. It is the default choice for new radar, EW and satcom designs across the region. The bottleneck is rarely the technology itself, it is finding a supplier who understands defence-grade traceability, can support long programme lifecycles, and ships from a Southeast Asian base with the right certifications.
If you are scoping a GaN-based RF chain for an aerospace, satellite or defence application and need component-level guidance or sample evaluation, reach out to our team in Singapore. We will help you match the right Altum RF amplifiers and supporting components to your specification, with full AS9120B-backed quality assurance from our Ubi Road office.