Marten Seth, Technical Marketing Manager, Finwave Semiconductor
Finwave’s innovative GaN (Gallium Nitride) on Silicon approach is advancing RF technology by delivering the reliability and durability essential for aerospace and military applications. From high-performance defense systems to the extreme conditions of space-based platforms like satellites, Finwave’s technology is designed to meet the most demanding requirements.
Over the last few years, Finwave has been hard at work developing RF products based on a novel GaN-on-Silicon process. The use of GaN-on-Silicon for radio frequency applications provides wide ranging benefits. Essentially, it combines the considerable performance benefits of GaN as a semiconducting material—typically paired with smaller, costlier Silicon Carbide (SiC) wafers—while utilizing larger silicon wafers to enable more efficient, cost-effective manufacturing and packaging. This way, the product gets both performance from GaN and the cost and manufacturability of industry standard CMOS.
Finwave’s GaN-on-Si RF switches are transforming the landscape of RF switching, moving beyond narrowband PIN diodes and low-power silicon switches to deliver high-power, high-speed, and broadband performance. This advancement accelerates the roll-out of new applications that demand both power and efficiency in a lightweight, easy to use form factor.
Thanks to their ease of use, fully integrated design (eliminating the need for external components) and light weight, Finwave GaN-on-Si-based switches are ideal for use within space-based applications such as Low Earth Orbit (LEO) satellites and Geostationary Satellites.
Reinventing RF Switching in Space
Typical applications for RF switches in spacecraft include switching between antennas, toggling between transmit and receive functions in TDMA-based systems, and selecting different radiation patterns in phased array antenna systems.
In addition to being mechanically robust enough to withstand the considerable vibration load during launch, the RF components used in space must be immune to the unforgiving nature of the environment. Requirements such as limits on outgassing, single event upset immunity and the ability to operate in a consistently high radiation environment are crucial. The electronics of spacecraft are built to survive the harshness of the space environment.
Finwave RF switches are simple to operate and do not require a driver. In this configuration, the switches are naturally free from single event upset, as there are no gates or driver stages that can introduce an error.
When tested for radiation tolerance, the truly disruptive potential of the GaN-on-Silicon switch process becomes evident. Collaborating with NASA JPL, we tested a FW2003 SP2T switch at radiation levels up to 500 krad for both DC and RF Performance, in both biased and non-biased conditions.
Looking at the DC performance, gate leakage current before and after exposure was tested. Any damage would show up as deviation of performance in the I-V Sweep. No difference is measurable in this test.
A simple way to understand this test is that semiconductors always rely on the small dimensions and thin insulating layers within the gate structure. Any damage to the gate would appear as a delta in an I-V diagram. An identical result is shown in Figure 2 for on-resistance measurement, where no measurable delta is observed before and after exposure.
RF performance was also evaluated before and after the test. If the transistors are damaged or altered in any way by the strong radiation environment, it will be visible in the S-Parameter measurement. Overlayed plots with both the before and after measurements are shown in Figure 3, revealing identical, broadband, low loss performance before and after the exposure stress event.
The Demands of Space
Many customers are already on their way to commercialize this technology in updated design concepts using Finwave GaN-on-Silicon RF switches. This new GaN-on-Silicon technology allows applications to benefit from GaN-based performance and reliability, while maintaining the simplicity and affordability of silicon-based devices. It is a great example where new technology can both help improve existing space-based usage while also enabling new applications where the complexity and cost of the GaN of Silicon Carbide is prohibitive.
Many customers are already incorporating Finwave’s GaN-on-Silicon RF switches into their next-generation design concepts, bringing this technology closer to commercialization. By combining the performance and reliability of GaN with the simplicity and affordability of silicon-based devices, this technological innovation not only enhances existing space-based applications but also supports the development of new ones—particularly in areas where the complexity and cost of GaN on Silicon Carbide have been limiting factors.
Evaluation boards with the entire line of Finwave Switch Products are now available. Please contact Finwave directly, or reach out to one of our authorized distributors.
