Check whether a rocket mission’s telemetry link closes during a delta-v event by combining transmitter power, antenna gains, free-space path loss, other losses, and receiver sensitivity. The calculator reports received power and link margin, helping engineers screen a communications design before detailed modulation, pointing, atmospheric, and noise-temperature analysis.
Positive link margin means the estimated received power exceeds the stated sensitivity; negative margin identifies the shortfall. This power-budget result is only as complete as the losses and receiver threshold entered.
Use a receiver sensitivity defined for the intended data rate, modulation, coding, and error-rate target. A positive result is not a reliability guarantee.
For 30 dBm transmit power, 3 dBi transmit gain, 155 dB path loss, 38 dBi receive gain, 4 dB other losses, and −105 dBm sensitivity, received power is −88 dBm and link margin is 17 dB.
Use the receiver threshold specified for the intended modulation, coding, data rate, bandwidth, and target error performance.
Only if you include the expected pointing penalty in Other link losses.
It is the mathematical threshold in this model, but practical designs commonly carry project-defined allowance for uncertainty and fading.
Convert it to dBm first; this calculator keeps every additive power-budget term in decibels.
A low-efficiency or poorly oriented antenna can have gain below an isotropic reference in the relevant direction.
| Input | Unit | Role |
|---|---|---|
| Transmitter power | dBm | RF power delivered toward the transmit antenna. |
| Transmit antenna gain | dBi | Gain in the link direction. |
| Free-space path loss | dB | Loss for the chosen frequency and range. |
| Receive antenna gain | dBi | Ground or relay receive antenna gain. |
| Other link losses | dB | Pointing, cable, polarization, and atmospheric losses. |
| Receiver sensitivity | dBm | Minimum acceptable received power. |