📡
Frequency
1406 MHz
Frequency
1406 MHz
🧭
Range
1400–1427 MHz
Range
1400–1427 MHz
🧩
Band Group
Passive EESS/RAS (1401–1418 MHz) — Lower-edge guard
Band Group
Passive EESS/RAS (1401–1418 MHz) — Lower-edge guard
🌐 Summary
The 1406 MHz allocation is part of the Passive EESS/RAS (1401–1418 MHz) — Lower-edge guard spectrum. This range is used worldwide for critical applications that keep our communications and infrastructure running smoothly. On this page we highlight how each band is applied in real systems, from regulatory assignments to everyday devices. Our goal is to make spectrum data clear and practical for engineers, regulators, and enthusiasts alike.
Key uses of this band include: Globally protected passive L‑band for EESS/RAS, including the HI line at 1420.4058 MHz. No intentional emissions; harmful interference prohibited. Strict guard from adjacent active bands; deep notches and coordination required..
HI line at 1420.4058 MHz; enforce radio-quiet and measurement protocols
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📡 Band & Geometry key
| Field | Value |
|---|---|
| Wavelength (m) | 0.213224 |
| Waveforms | Not applicable (noise-like radiometry; spectral lines for astronomy) |
| Antenna Form Factor (Typical) | Satellite radiometers; large radio astronomy dishes/arrays |
| Band Family | Passive Services / L‑Band |
| Band | 1400–1427 MHz Earth Exploration Satellite (Passive) & Radio Astronomy (Passive) — Protected |
| Primary Common Name | L-band |
| FSPL @ 1 km [dB] | 95.4 |
| FSPL @ 10 km [dB] | 115.4 |
| Fresnel Radius @ 1 km (m) | 7.301 |
| Band Group | Passive EESS/RAS (1401–1418 MHz) — Lower-edge guard |
| Tax Band Family | UHF/L-band Transition |
| Tax Band Class | 1400 MHz – 1427 MHz UHF/L-band Transition Passive (EESS / RAS) |
🧩 Applications & Usage
| Field | Value |
|---|---|
| Primary Application | Passive microwave radiometry (soil moisture, ocean salinity) and radio astronomy observations |
| Lower Neighbor Use | Radiolocation / Aeronautical (≤1400 MHz) — strict OOBE into passive band |
| Upper Neighbor Use | Mobile/fixed services (≥1427 MHz) in many regions — tight masks |
| Typical Services Devices | – |
| Market Common Devices | Passive sensors and observatory receivers |
| Refarming Use | – |
| Device Ecosystem Size | – |
| Device Hotspots (MHz) | – |
| Device Category | – |
| Typical Use Cases | – |
| Modulation (Device) | – |
| Channel Width (Device) [kHz] | – |
| Device Region Profiles | – |
| Per-Region EIRP Or Duty (Device) | – |
| Allocation Relevance (Device) | – |
| Adjacent-Band Collision Risks (Device) | – |
| Example Devices Or Skus | – |
| Common Protocols | Not applicable |
🗒️ Notes
| Field | Value |
|---|---|
| Receiver Selectivity Notes | – |
| Interference Notes | – |
| Compatibility Risk Notes | Extremely sensitive passive band (EESS/RAS). Harmful interference prohibited. |
| Notes | HI line at 1420.4058 MHz; enforce radio-quiet and measurement protocols |
| Propagation Notes | Observation-driven; requires ultra‑low interference environments |
⚙️ Technical Rules
| Field | Value |
|---|---|
| Lower Band Frequency Limit | 1400 |
| Upper Band Frequency Limit | 1427 |
| EIRP Indoor Limits | – |
| EIRP Outdoor Limits | – |
| PSD Limit | – |
| Emission Mask Class | – |
| Guardband Minimum [kHz] | – |
| Typical Bandwidths | Radiometric 1–27 MHz (instrument-dependent) |
| Autocalculated Bandlimits | 1400.0–1427.0 MHz |
| Typical Bandwidths (Estimated) | Radiometric 1–27 MHz (instrument-dependent) |
| Max EIRP [dBm] | – |
| Power Source Or Duty Profile (Typical) | Receive-only instruments; duty governed by observation schedules |
| Channelization Plan | – |
| Channelization | Not applicable (radiometry/astronomy) |
| Guard Band Requirement | ≥1–3 MHz above 1400 MHz edge; aggressive OOBE control |
| OOB Emission Limit [dBm/MHz] | – |
| Spurious Emission Limit (dBm) | – |
| RX Blocking Min [dBm] | – |
| Duplexing | Not applicable |
| Duplexing Information | Receive-only scientific services; no paired links |
| Uplink Pairing | Not applicable |
| Downlink Pairing | Not applicable |
| Paired Band Info | Not applicable |
| Max EIRP [dBm] | – |
| Channelization Block Size | – |
| 3GPP Band Number | |
| Example 3GPP Bands | None (passive) |
| LTE Uplink Bands | – |
| LTE Downlink Bands | – |
| NR Uplink Bands | – |
| NR Downlink Bands | – |
| Guard Bands | Recommend ≥2–5 MHz protection near 1400 MHz and 1427 MHz edges; apply sharp filtering and site separation for adjacent allocations. |
| Protocol Or Standard | – |
🌎 Country Overrides
| Field | Value |
|---|---|
| Tax Service Category | Earth Exploration / Science |
| Tax License Type | Passive (no intentional emissions) |
| Tax Regions | Global (ITU Regions 1/2/3) — highly protected |
| ITU Region 1 (Europe, Africa, Middle East (west of Persian Gulf), Western Russia & Mongolia) | Region 1 (EMEA): Passive allocations (EESS/RAS) — very high protection; strict OOBE from neighbors. |
| ITU Region 2 (North America, South America, Central America, Caribbean, Greenland, Eastern Pacific Islands (Americas region)) | Region 2 (Americas): Passive (EESS/RAS); HI line protection emphasized; harmful interference unlawful. |
| ITU Region 3 (Asia, Australia, Pacific Islands, Oceania, Indian Subcontinent, East Asia & Southeast Asia) | Region 3 (APAC): Passive scientific services; enforce quiet bands; strong protection expectations. |
| License Type | Receive‑only / Protected (No in‑band transmissions) |
| Primary Application | Passive microwave radiometry (soil moisture, ocean salinity) and radio astronomy observations |
| Primary Services | EESS (Passive), Radio Astronomy (Passive) |
| Spurious Emission [dBm] | – |
| Lower Neighbor Use | Radiolocation / Aeronautical (≤1400 MHz) — strict OOBE into passive band |
| Upper Neighbor Use | Mobile/fixed services (≥1427 MHz) in many regions — tight masks |
| Licensing Model | Receive-only; protection from harmful interference per national/ITU rules |
| Typical Services Devices | – |
| US FCC Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited– |
| CA IC Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited– |
| UK Ofcom Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited– |
| US Ref | – |
| Typical Bandwidths | Radiometric 1–27 MHz (instrument-dependent) |
| Market Licensing Model | Not commercial spectrum; emissions prohibited in‑band |
| Market Common Devices | Passive sensors and observatory receivers |
| Fresnel Radius (1st, 1 km) [m] | 7.301 |
| Typical Bandwidths (Estimated) | Radiometric 1–27 MHz (instrument-dependent) |
| Auction Status | Not auctioned (protected passive band) |
| Refarming Use | – |
| Typical Site Spacing km | N/A; observatories/radiometers follow mission siting / N/A; radio-quiet zones for observatories |
| Device Ecosystem Size | – |
| Traffic Load Share | – |
| Device Hotspots (MHz) | – |
| Device Category | – |
| Typical Use Cases | – |
| Typical Center Frequencies [MHz] | – |
| Rule Part (Fcc Or Region) | – |
| Modulation (Device) | – |
| Channel Width (Device) [kHz] | – |
| Device Region Profiles | – |
| Per-Region EIRP Or Duty (Device) | – |
| Allocation Relevance (Device) | – |
| Adjacent-Band Collision Risks (Device) | – |
| Example Devices Or Skus | – |
| Antenna Form Factor (Typical) | Satellite radiometers; large radio astronomy dishes/arrays |
| Power Source Or Duty Profile (Typical) | Receive-only instruments; duty governed by observation schedules |
🛡️ Regulatory & Neighbors
| Field | Value |
|---|---|
| Lower Band Frequency Limit | 1400 |
| Upper Band Frequency Limit | 1427 |
| Rx Blocking Min dBm | – |
| Lower Neighbor Use | Radiolocation / Aeronautical (≤1400 MHz) — strict OOBE into passive band |
| Upper Neighbor Use | Mobile/fixed services (≥1427 MHz) in many regions — tight masks |
| Lower Neighbor Band | Radiolocation / Aeronautical |
| Lower Neighbor Range | 1300–1400 MHz |
| Upper Neighbor Label | Active services (varies by region) |
| Upper Neighbor Range | 1427–1452 MHz (varies) |
| Adjacent-Band Collision Risks (Device) | – |
| Real-World Range (Indoor/Outdoor) | – |
| US FCC Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibitedEESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited |
| CA IC Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibitedEESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited |
| UK Ofcom Alloc | EESS (passive); Space research (passive); Radio astronomy — harmful interference prohibitedEESS (passive); Space research (passive); Radio astronomy — harmful interference prohibited |
| Regulatory References | US: -; CA: -; UK: – |
| Global Harmonization | Strongly harmonized passive allocation |
| Crossborder Coordination | – |
| Sharing Mechanism | No in‑band sharing (passive only); adjacent‑band users employ geographic separation, time scheduling, and strict OOBE masks; coordination with radio observatories required. |
| Auction Status | Not auctioned (protected passive band) |
| Guard Or Pair | – |
📈 Market & Measurements
| Field | Value |
|---|---|
| Noise Floor | Extremely low required for passive sensing |
| Interference Cases | Leakage/spurious from active services below/above; satellite downlinks outside band |
| Lower Neighbor Range | 1300–1400 MHz |
| Upper Neighbor Range | 1427–1452 MHz (varies) |
| Interference Notes | – |
| Market Licensing Model | Not commercial spectrum; emissions prohibited in‑band |
| Market Commercial Value | Scientific/regulatory; not commercial spectrum |
| Market Common Devices | Passive sensors and observatory receivers |
| Market Deployment Density | Limited to scientific missions/observatories |
| Noise Floor (Estimated) | Extremely low required for passive sensing |
| Market Commercial Value (Estimated) | Scientific/regulatory; not commercial spectrum |
| Ecosystem Maturity | – |
| Indoor Penetration | – |
| Known Interference | Highly susceptible to interference from adjacent services; protect against transmitters below 1400 MHz and above 1427 MHz; avoid high‑EIRP links near observatories. |
| Device Ecosystem Size | – |
| Real-World Range (Indoor/Outdoor) | – |
| Antenna Form Factor (Typical) | Satellite radiometers; large radio astronomy dishes/arrays |
| Ecosystem Maturity | – |
| Device Ecosystem Size | – |
| Chipset Availability | – |
| Operator Deployments | – |
| Technology Generations Deployed | – |
| Roaming Support | – |
| Traffic Load Share | – |
| Indoor Penetration | – |
| Known Interference | Highly susceptible to interference from adjacent services; protect against transmitters below 1400 MHz and above 1427 MHz; avoid high‑EIRP links near observatories. |
| Occupancy | Scientific observation windows; no intentional emissions |
| Occupancy Bucket Pct | N/A (passive) |
| Latency Profile | – |
| Common Channels Or Profiles | – |
| Security Features | – |
| Lbt Or Fhss Requirement | – |
| Popularity (Installed Base) | – |
| Coexistence Tips | Deep notches; tight masks; exclusion/coordination zones; measure and log emissions near band edges. |
| Latency Class | Not applicable; science observations |
| Device Hotspots (Scoped && Tagged) | 1420.4058 MHz (HI line) |