SPRACP3D November 2019 – August 2026 AWR6843 , AWR6843AOP , IWR1443 , IWR1642 , IWR6443 , IWR6843 , IWR6843AOP
An LPR must operate with a minimum 50MHz BW, no matter which frequency band the LPR is operating under. For this section, the FCC defines the BW as the width between two points found above and below the center frequency which experience a 10dB drop of power outside. This is distinct from the ETSI regulations which use a 20dB drop.
| Permitted Band of Operation (GHz) | Avg EIRP (dBm in any 1MHz) | Peak EIRP (dBm in any 50MHz) |
|---|---|---|
|
5.925-7.250 |
-33 |
7 |
|
24.05-29.00 |
-14 |
26 |
|
75-85 |
-3 |
34 |
The FCC places a limit on both the average and the peak EIRP of an LPR. This is done in a special manner compared to other operations. The FCC doesn't use spectral density like the ETSI. Rather, for the average EIRP, the FCC requires it be computed by finding the average EIRP by finding and reporting the maximum power level found within any 1MHz BW while using a power averaging detector. You can imagine this as having an averaging detector with a 1MHz window that slides across the BW and reports only the highest power it detected as well as the frequency it was detected.
For the peak power, the FCC uses a peak power detector with a 50MHz BW centered at the location of the of the frequency with the highest average power detected. This 50MHz BW must be entirely located within the authorized BW shown above. In the case where the RBW of the detector is less than 50MHz, as is often the case, the Peak EIRP limit is reduced according to the table below. Keep in mind that the RBW must not be lower than 1MHz or greater than 50MHz. The VBW must not be less than the RBW.
| Detector RBW (MHz) | EIRP Limit Reduction |
|---|---|
| 50 | N/A |
| 1 ≥ RBW > 50 | 20 × log(RBW/50)dB |