High-Power Switched Filter Banks Pose Design Challenges

摘要

Switched Filter Banks (SFBs) are traditionally found in RF front ends or intermediate stages of sensitive receivers for military and defense applications, as they help reduce harmonic and spurious content which is critical to communications systems. Until recently, high-power SFBs (Fig. 1) have been limited to fixed locations or on larger mobile platforms due to their inherent large size. Gallium-nitride (GaN) power amplifiers (PAs) have reduced the size and weight of high-power transmitters in the hundreds of watts range. The demand for SFB assemblies has thus followed suit. However, the leap from traditional SFBs to high-power equivalents is not straightforward, and many tradeoffs and design considerations must be made in order to develop a suitable high-power SFB.