Placing an LNA at the antenna instead of the receiver typically improves system noise figure by several dB, because cable loss affects the signal far less after amplification than before it. Enter your cable loss and LNA specs below to see the exact difference for your setup.
How is this calculated?
This uses the Friis cascade noise figure formula, which combines the noise contribution of each stage in a signal chain, accounting for how much gain (or loss) came before it. A cable is treated as a lossy passive stage: its noise figure equals its loss in dB, and its "gain" is negative (i.e. a loss).
The key asymmetry: a stage's noise contribution gets divided down by all the gain that came before it — but multiplied up by all the loss that came before it. That's why cable loss matters so much more when it comes before the LNA than when it comes after.
See our Remote LNA guide for the full explanation, or shop our LNAs →