How High-Q Ceramic Filters Help Engineers Overcome GNSS Jamming

As Global Navigation Satellite System (GNSS) receivers are increasingly embedded into technologies like autonomous vehicles, drones, and precision agriculture systems, maintaining signal integrity in congested radio frequency (RF) environments becomes a major challenge. These receivers often operate under conditions rife with interference, making them highly susceptible to jamming—whether intentional or accidental. Even low-power jamming can degrade positioning accuracy or completely block GNSS reception.

High-Q ceramic bandpass filters provide a reliable solution to combat this interference. Unlike common Surface Acoustic Wave (SAW) filters, which are compact and cost-effective but limited in out-of-band rejection, high-Q ceramic filters offer superior performance in environments demanding greater selectivity and thermal stability. These filters effectively isolate weak GNSS signals—typically around -130 dBm—from overpowering adjacent-band noise and intentional jamming signals.

The Q factor, or quality factor, is a key performance metric for RF filters. It reflects the filter’s ability to maintain energy with minimal losses, enabling sharper frequency selectivity and lower insertion loss. Knowles' high-Q ceramic filters excel in these metrics, offering enhanced rejection of unwanted signals and preserving the integrity of critical GNSS transmissions.

Applications such as military drones operating in contested zones or autonomous farm equipment requiring sub-inch navigation precision demand resilient and accurate positioning. Knowles’ high-Q ceramic filters, including options like the GPS L1, are engineered specifically for these high-performance needs. They deliver up to 40 dB out-of-band rejection and low insertion loss (<2.0 dB), making them vital components for robust and reliable GNSS-enabled systems.