SatCom & RF systems

Build the link. See the budget.

Start with two antennas and free-space loss, then insert RF and propagation blocks. ApertureLab propagates carrier power and tracks receiver NF, noise temperature, C/N₀, SNR, Eb/N₀, and margin.

Default model TX antenna → FSPL → RX antenna Receiver NF is calculated from blocks after the RX antenna plus the backend receiver NF.

Link setup

Core parameters

Frequency GHz Slant range km TX input power dBm Noise bandwidth MHz Data rate Mbps Backend receiver NF dB Required E_b/N₀ dB Reference temperature K

EIRP—dBm

Total path loss—dB

Received carrier—dBm

Receiver NF—dB

G/T—dB/K

C/N₀—dB-Hz

SNR—dB

E_b/N₀—dB

Link margin—dB

Block builder

Signal chain

TX chain Propagation RX chain / NF

Use the + buttons to insert blocks. Select any block to edit its parameters. Core TX antenna, FSPL, and RX antenna blocks remain in the chain.

Power ledger

Link contributions

Receiver

Noise & system metrics

Stage-by-stage

Carrier, NF, and SNR progression

Cascaded NF begins after the RX antenna. Passive loss before the first LNA is therefore visible immediately.

Stage	Region	Gain / loss	Carrier out	Stage NF	Cascade NF	SNR

Calculation model & assumptions

Free-space lossFSPL = 92.45 + 20log₁₀(fGHz) + 20log₁₀(dkm)

Cascade noise factorF = F₁ + (F₂−1)/G₁ + (F₃−1)/(G₁G₂) + …

System noise temperatureTsys = Tantenna + (Freceiver−1)T₀

SNRSNR = C/N₀ − 10log₁₀(B)

Eb/N₀Eb/N₀ = C/N₀ − 10log₁₀(Rb)

Passive block NFTe = (L−1)Tphysical; F = 1 + Te/T₀

This first version assumes a single one-way hop. Antenna gains are treated as realized gains. Atmospheric, rain, pointing, and polarization effects are entered as deterministic losses. Receiver noise is referred to the RX-antenna terminals.