The 1640 MHz frequency sits in the L-Band (1–2 GHz) of the radio spectrum and plays a critical role in satellite navigation, telemetry, surveillance systems, and space-to-Earth communication. Although not as universally known as bands used for LTE or Wi-Fi, 1640 MHz is integral to aerospace and scientific applications and is often tightly regulated.
Center Frequency : 1640 MHzTypical Range : 1610–1660.5 MHzITU Band : L-Band (ITU designation: Region 1, 2, and 3 compliant)Wavelength : ~18.29 cm
This frequency range overlaps or borders bands used for satellite navigation , radionavigation-satellite services (RNSS) , and space operation systems .
🌐 Region Use of 1640 MHz Status 🌍 Region 1 Scientific and satellite services Primary or shared 🌎 Region 2 RNSS, telemetry, spectrum surveillance Shared, harmonized 🌏 Region 3 Satellite comms, telemetry (select areas) Varies by country
Application Description GNSS Downlink Channels 1640 MHz lies within ranges used by GNSS constellations like GLONASS Telemetry (Aerospace) Downlink for vehicle health monitoring and control systems Spectrum Surveillance / SIGINT Used by state and defense agencies for spectrum monitoring Space Research & Operations Receives data from spacecraft for scientific and observational missions Custom Scientific Experiments Earth-space radio signal propagation, ionospheric studies, etc.
Attribute Value Center Frequency 1640 MHz Modulation Types QPSK, BPSK, FSK, custom spread spectrum Antenna Type Helical, patch, directional arrays Typical Bandwidth Varies: 2–10 MHz allocations or narrowband Link Type Downlink or simplex (space-to-Earth) Power Levels Low-power (<10 W) to high-gain satellite class
Organization Role ITU Global coordination and regional harmonization FCC (USA) Regulates use within Region 2, especially for GNSS ESA / CNES / ISRO Space-based services using or bordering this band Military & Intel Agencies May reserve segments for non-public applications
Heavily regulated due to international coordinationNot for license-free use Subject to coordination between civil and military entities
Potential for harmful interference with GNSS and aircraft telemetry if misused
Shared spectrum with GLONASS signals (~1602–1616 MHz)
Adjacent to Earth Exploration Satellite Service (EESS) bands
Careful filtering and coordination required to prevent satellite downlink interference
Spectrum monitoring often enforced near this band for compliance
Band Frequency Range Use 1610–1626.5 MHz RNSS (e.g., GLONASS), Iridium uplinks 1626.5–1660.5 MHz Mobile satellite service (MSS), telemetry, Inmarsat 1660.5–1670 MHz Meteorological satellite, passive sensing 1670–1675 MHz Earth Exploration Satellite Service
Feature Value / Description Center Frequency 1640 MHz ITU Region 🌍 Region 1, 🌎 Region 2, 🌏 Region 3 Primary Use GNSS-related downlink, aerospace telemetry Access Licensed only, tightly regulated Notable Risks GNSS interference, satellite downlink overlaps Key Stakeholders Space agencies, defense, spectrum authorities
Ideal for long-distance downlink from LEO/MEO spacecraft
Antenna designs require high directivity for low-EIRP signals
Filtering is critical due to proximity to sensitive navigation bandsOften used in custom SDR setups for space weather and science studies
