Satellite Link Budget + EU Dual-Use Assessment
Two sections in one tool: calculates RF satellite link budget using Friis FSPL formula (client-only, D-53-07) and assesses orientation under dual-use EU Reg. 2021/821 Annex I with AI-enhanced export compliance.
The link budget satellite is the fundamental calculation to determine if a radio link between a satellite and a ground terminal is feasible. The free-space path loss (FSPL) dominates the energy balance over distances GEO (~35,786 km) or LEO (~550 km). The Friis formula - FSPL (dB) = 20·log₁₀(d_km) + 20·log₁₀(f_MHz) + 32.45 - is verified and universally used in RF engineering.
The second section addresses the dual-use assessment: Regulation (EU) 2021/821 (in force since September 9, 2021, which repeals Regulation 428/2009) governs the export of goods, software, and technologies with civilian and military applications. Annex I organizes control entries into 10 categories (0-9), with alphanumeric codes similar to those in the Wassenaar Agreement. Satellite components - high-gain antennas, VSAT terminals, propulsion systems - often fall under Categories 5, 7, or 9.
The satellite presets included in the tool (GEO Ku-band, LEO Ku-band) are assumed and must be replaced with real parameters (EIRP, G/T) provided by the satellite operator. The FSPL calculation is verified; margin thresholds (≥10 dB = adequate) are engineering rules of thumb [ASSUMED].
Fonte RF: Equazione di trasmissione di Friis; ITU-R + 3GPP TS 36.101/38.101 (preset - [ASSUMED]). Fonte dual-use: Reg. (UE) 2021/821, EUR-Lex (in vigore 9 settembre 2021). Dati dual-use: [ASSUMED - verificare Annex I EUR-Lex].
Presets Values [ASSUMED] - replace with actual satellite parameters (EIRP, G/T from datasheet).
RF Parameters
Result
No results
Enter values and press the button to calculate.
Calculation Examples
Example A - LoRaWAN 915 MHz, 15 km [Golden reference case]:
- FSPL = 20·log₁₀(15) + 20·log₁₀(915) + 32.45 = 23.52 + 59.23 + 32.45 = 115.20 dB [VERIFIED]
- Margin = Tx(+14) + Tx_ant(+2) + Rx_ant(+5) – FSPL(115.20) – Rx_sens(-137) = +42.80 dB
- Chip state: Sufficient margin (≥10 dB) [ASSUMED threshold]
LoRaWAN Preset: txPower=+14 dBm, txGain=+2 dBi, rxGain=+5 dBi, rxSensitivity=-137 dBm [all ASSUMED - Semtech SX1276 datasheet]
Example B - Dual-use classification:
- Product: "Ku-band VSAT Terminal with 256-bit AES Encryption for Broadband Satellite Communications
- Trigger: presence of "AES encryption" → potential Cat. 5 Part 2 (Information Security) [ASSUMED]
- Outcome: PROBABLY CONTROLLED Category 5 - check ANC (MIMIT for Italy) for formal classification
Glossary
- Free Space Propagation Loss
- Radio signal power loss for free-space propagation. Friis formula: FSPL (dB) = 20·log₁₀(d_km) + 20·log₁₀(f_MHz) + 32.45. Excludes atmospheric attenuation, rain, multipath.
- Effective radiated power
- Equivalent Isotropic Radiated Power = Transmit Power (dBm) + Transmit Antenna Gain (dBi). GEO satellites typically specify EIRP in dBW (add 30 to convert to dBm).
- Annex I (Reg. EU 2021/821)
- Dual-use attached control list under Reg. (EU) 2021/821. Organizes controlled items into 10 categories (0-9) with alphanumeric codes. Updated periodically to align with Wassenaar Agreement. [ASSUMED - check EUR-Lex for current version]
- NCB - National Competent Authority
- National authority responsible for issuing dual-use export licenses in each EU country. For Italy: MIMIT - Ministry of Enterprises and Italian Manufacturing [ASSUMED]. The formal classification and export license belong exclusively to the ANC.
- ECCN vs EU Annexe I
- ECCN (Export Control Classification Number) is the US system managed by BIS (Department of Commerce). Annex I EU is the European system under Reg. 2021/821. Although they use a similar structure (Wassenaar legacy), they are SEPARATE and independent regimes.
Frequently Asked Questions
What is satellite link budget and what does margin measure?
The budget link is the calculation that balances transmitted power with path loss (FSPL, Free-Space Path Loss) and receiver sensitivity to determine if the RF connection is closed. The margin is the difference in dB between received power and minimum sensitivity: a margin ≥10 dB is considered adequate for production systems [ASSUMED - engineering rule-of-thumb], 0–9 dB is marginal and <0 dB means the link is not closed.
What does FSPL mean and how is it calculated?
FSPL (Free-Space Path Loss) is the signal power loss in free space without obstacles or atmospheric attenuation. It is calculated using the Friis formula: FSPL (dB) = 20·log₁₀(d_km) + 20·log₁₀(f_MHz) + 32.45. For a GEO satellite at 35,786 km in Ku band 11.7 GHz, FSPL is approximately 205 dB [NUMERICALLY VERIFIED].
What is EU Regulation 2021/821 and what are dual-use products?
The EU Regulation 2021/821 is the European legal framework for controlling exports of "dual-use" items - goods, software, and technologies with both civilian and military applications. Annex I lists 10 categories (0-9: nuclear, materials, electronics, computers, telecommunications, sensors, navigation, marine, aerospace). The tool provides initial guidance; formal classification is the responsibility of the National Competent Authority (NCA).
What is the difference between ECCN (US) and Annex I EU?
ECCN (Export Control Classification Number) is the US system managed by BIS on the Commerce Control List. The EU Annex I system is managed by National Competent Authorities of EU Countries under Reg. 2021/821. Though sharing a similar alphanumeric structure (derived from the Wassenaar Arrangement), they are two SEPARATE and independent systems. A product may be controlled under one, both, or neither of these regimes.
Are RF calculations accurate for real systems?
The FSPL formula by Friis is accurate for free space [VERIFIED] but does not account for atmospheric attenuation, rain fade, multipath, antenna pointing, and other real-world factors. The satellite presets are [ASSUMED] and must be replaced with the actual satellite parameters (EIRP, G/T of terminal) provided by the operator. The calculation is a preliminary estimate - for production systems, a complete analysis with professional RF software is required.
How is it used?
- Select section
Choose between section A (Satellite RF Link Budget Calculation) to estimate link margin, or section B (Dual-Use Assessment) for guidance on EU Reg. 2021/821 Annex I classification.
- Section A - Configure RF Parameters
Use a satellite preset (GEO Ku-band, LEO Ku-band, LoRaWAN) or enter manually: frequency (MHz), distance (km), TX power (dBm), TX/RX antenna gain (dBi), and receiver sensitivity (dBm). FSPL + margin calculation happens in browser - no data sent to server.
- Section B - Describe the dual-use product
In section B, describe the product or technology to be verified (e.g., "Ku-band VSAT terminal with AES 256-bit encryption"). The tool provides a guidance on the potential Annex I category. For detailed AI analysis (Reg. EU 2021/821), use the "AI Analysis" button.
- Interpret the result and consult ANC
The RF margin indicates if the link is closed (≥0 dB) and by how much margin (≥10 dB = adequate). The dual-use classification is always advisory: the formal classification belongs to the National Competent Authority (NCA) of the exporting EU country.
Do you need a custom analysis?
This tool is free and informative. For in-depth AI-powered export compliance analysis locally or professional RF simulations, contact Federico.