Jammer Effectiveness Calculator
Unified J/S ratio and effective range analysis. Enter the scenario geometry to see both the jamming ratio at your current position and the maximum range at which jamming succeeds. Select a drone model to auto-fill GCS and frequency parameters.
Target Drone Model (optional)
Jammer
Omni ≈ 0–3 · Panel ≈ 9–14
Current jammer-to-drone distance — used to compute J/S at this geometry
Ground Control Station
Consumer: 0.025–0.1 W
Consumer omni ≈ 2 dBi
GCS-to-drone distance
J/S Ratio at Scenario Geometry
+13.8 dB
Effective Jamming
Max Jamming Range (J/S = 0 dB)
2.46 km
current position (500 m) is within range ✓
Jammer EIRP (rated): 46.0 dBm → effective 29.8 dBm after BW penalty
GCS EIRP: 22.0 dBm
GCS signal at drone: -78.0 dBm (Friis, 1000 m)
Bandwidth penalty: -16.2 dB — 83 MHz sweep ÷ 2 MHz channel = 2.4% effective power
Geometry: jammer 500 m · GCS 1.00 km from drone (— jammer closer ✓)
Power Sweep — 6 dBi · 2.4 GHz · BW penalty -16.2 dB
| Rated Power | Eff. EIRP | J/S @ 500 m | Max Range |
|---|---|---|---|
| 1 W | 19.8 dBm | +3.8 dB | 778 m |
| 5 W | 26.8 dBm | +10.8 dB | 1.74 km |
| 10 W | 29.8 dBm | +13.8 dB | 2.46 km |
| 20 W | 32.8 dBm | +16.9 dB | 3.48 km |
| 50 W | 36.8 dBm | +20.8 dB | 5.50 km |
| 100 W | 39.8 dBm | +23.8 dB | 7.78 km |
J/S Ratio Reference
| ≥ +6 dB | Reliable jamming — jammer has clear power advantage |
| 0 to +6 dB | Marginal — disruption possible but not guaranteed |
| < 0 dB | Insufficient — control signal dominates |
Formulas
J/S (dB) = [10·log₁₀(Pj·Bc/Bj) + Gj] − [10·log₁₀(Ps) + Gs] + 20·log₁₀(Rs / Rj)
R_max = (λ/4π) × √(Pj·(Bc/Bj)·Gj / P_gcs_at_drone)
Bc = drone control channel bandwidth · Bj = jammer sweep bandwidth · Rs = GCS-to-drone distance · Rj = jammer-to-drone distance. P_gcs_at_drone is computed from GCS parameters via Friis. All models assume free-space propagation and omnidirectional drone antenna (0 dBi). Real-world effective range is typically 30–60% of R_max.