Satellite Navigation / KPS

KPS: Technology and Filter Requirements

The Korean Positioning System (KPS) represents South Korea's ambitious initiative to establish an independent regional satellite navigation system, significantly reducing reliance on global networks like GPS. The technological architecture is based on a constellation of eight satellites (3 GEO and 5 IGSO), primarily covering the Korean Peninsula and the Asia-Oceania region. KPS operates in the traditional L-band navigation frequencies (L1: 1559 MHz to 1610 MHz, L2: 1215 MHz to 1300 MHz, L5: 1164 MHz to 1215 MHz), as well as the innovative L6 band (1278.75 MHz) and the S-band (2483.5 MHz to 2500 MHz). The primary technical challenge lies in the region's massive spectral density: the Korean Peninsula features one of the highest concentrations of 5G gNodeBs (especially in the n78 band at 3.5 GHz) and Remote Radio Units (RRUs) , whose harmonics and out-of-band emissions can saturate high-sensitivity navigation front-ends. Wainwright Instruments provides specialized high-performance filters for this demanding infrastructure, tailored exactly to the narrowband signals of KPS. Since Korea leads in robotics and autonomous driving, centimeter-accurate positioning under difficult urban conditions in Seoul or Busan is essential. Our filter solutions feature extreme skirt steepness to protect high-sensitivity KPS receivers from saturation by neighboring Small Cells and Massive MIMO arrays. Exceptional group delay stability ensures the integrity of time referencing for critical infrastructures, with a focus on precision components optimized for high-performance base stations and professional test environments.

Typical Deployment Scenarios

In South Korea's high-tech environment, KPS filters function as critical protective barriers to fully exploit the benefits of regional satellite architecture under maximum RF load.

Autonomous Driving & V2X Communication: In the urban canyons of Incheon or Seoul, our filters protect KPS receivers in autonomous vehicles from overloading by the dense 5G infrastructure, ensuring lane-accurate navigation at the centimeter level.
Maritime Monitoring & Safety: In the busy coastal waters off Busan, our robust filters protect receiver front-ends on ships from saturation by powerful on-board radar systems in the S-band and X-band.
Industrial Robotics & Intralogistics: In automated warehouses and manufacturing sites, our components secure KPS signals against electromagnetic pulses from heavy-duty machinery and private 5G campus networks.
Critical Time Referencing (Timing): At national telecommunication base stations, our filters protect GNSS timing antennas from the extreme transmit power of their own gNodeBs and Remote Radio Units (RRUs) on the same mast.
Disaster Management & Emergency Alerts: KPS transmits critical messages during natural disasters; here, our filter solutions guarantee fail-safe signal detection even when terrestrial networks are burdened by extreme radio loads in the Sub-6 GHz range.
Precision Agriculture: For automated farming in rural regions, our filters effectively suppress neighboring cellular signals from rural macro cells, preventing positioning jumps.
Military & Government Communication: In protected receivers, our filter solutions prevent signal blocking from intentional jamming or atmospheric broadband interference in strategically sensitive zones.
Research & Certification Laboratories: To validate the interference immunity of new KPS components, we supply high-precision reference filters to characterize hardware performance under controlled laboratory conditions against simulated 5G interference.

Suitable Filter Categories for Satellite Navigation / KPS

The combination of extreme receiver sensitivity and massive terrestrial radio load demands filter solutions that combine extraordinary selectivity and thermal stability.

Band Pass Filters

Our KPS Band Pass filters enable precise selection of the primary carrier frequencies in the L1 band (1575.42 MHz), L2 band (1227.60 MHz), and L5 band (1176.45 MHz), as well as the Korea-specific L6 band (1278.75 MHz). In professional Remote Radio Units and stationary reference receivers, these filters eliminate unwanted signals from neighboring bands such as the Iridium spectrum or Globalstar. For the S-band (2483.5 to 2500 MHz), we offer specialized solutions that separate navigation signals from Wi-Fi 7 emissions and Bluetooth interference. The high quality factor of these filters ensures that the Signal-to-Noise Ratio (SNR) is maximized, even when utilizing correction data at the millimeter level. Manufacturers of infrastructure components benefit from the high power handling and precision of our filters.

Manually Tunable Band Pass Filters

For the development of KPS hardware in research institutions such as KARI (Korea Aerospace Research Institute), we provide manually tunable Band Pass filters covering wide ranges from 1.1 GHz to 3.0 GHz. Via high-precision mechanical tuning elements, the passband can be adjusted exactly to specific KPS signals (e.g., B1C or B2a compatible channels). This flexibility allows engineers to investigate prototype robustness against targeted broadband interference or coexistence with Galileo and BeiDou services in the lab. The mechanical precision guarantees permanent reproducibility of the filter curve for consistent test series during the validation of multi-GNSS front-ends.

Digitally Tunable Band Pass Filters

Electronically controllable filters support modern Software Defined Radio (SDR) architectures that must react agilely to various orbital constellations. Via digital interfaces, filter parameters can be adjusted in real-time, which is particularly advantageous for automated test sequences checking channel selectivity in the S-band (2492 MHz center frequency). Our digitally tunable filters combine digital control precision with the necessary RF quality and are optimized for use in test environments and development systems. They enable rapid reconfiguration of test scenarios without manual hardware swaps, supporting efficient quality assurance processes in KPS terminal manufacturing.

Band Reject Filters / Notch Filters

Our KPS notch filters serve to eliminate specific, high-energy interfering signals located immediately adjacent to or within the navigation spectrum. Particularly critical is the suppression of 5G n78 signals (3,300 MHz to 3,800 MHz), which can bleed into the L1/L5 bands via intermodulation. Strong emissions from L-band radar systems (1,215 MHz to 1,400 MHz) are also effectively masked, while the remaining passband for navigation data remains virtually unaffected. This protection is fundamental to prevent saturation of high-sensitivity Low Noise Amplifiers (LNAs) in urban environments with a high density of gNodeBs. By using our notch filters, the robustness of the infrastructure against narrowband interferers is massively increased.

Monoplexer / Diplexer / Duplexer / Triplexer

Combining or separating various KPS bands (L1, L2, L5, L6) on a shared antenna structure requires high-performance multiplexers with extremely high isolation. Our duplexers and triplexers for GNSS applications enable the simultaneous use of GPS L1 and KPS S-band with minimal mutual interference. Wainwright Instruments manufactures these components with a focus on minimal group delay distortion, ensuring that positioning accuracy for applications such as KPPP (Kinematic Precise Point Positioning) is not compromised. Precise tuning prevents signal crosstalk and protects sensitive receiver paths from overloading by external terrestrial radiation. Our multiplexers are optimized for use in professional navigation systems and industrial infrastructure applications.

Absorptive Filters

Absorptive filters play a crucial role in the transmission infrastructure of KPS signal simulators and ground-based broadcast stations to preserve the spectral purity of the generated signal. Instead of conducting unwanted harmonics or reflections back to the power amplifier or generator, these filters safely convert them into heat, preventing signal distortion in the L-band. This is particularly important for complying with strict regulatory masks for test transmitters in the 1.1 GHz to 1.6 GHz frequency range. Our absorptive filters are designed for continuous operation and increase simulation precision by consistently minimizing thermal stress.