An overview of FCC regulations

AN4378

4/19

DocID025421 Rev 1

Part 15.205 shows the bands where only spurious emissions are permitted (see Table 1).

The field strength of emissions appearing within these frequency bands shall not exceed the

limits shown in part 15.209. The tables that follow show the restricted bands as defined in

part 15.205, and the radiated and conducted emission limits are defined in part 15.209. In

Table 2 the maximum permissible electric field strength at a specific measurement distance

is reported, along with the equivalent EIRP value. To determinate the equivalent EIRP

value, the formula described in “Guidance for Performing Compliance Measurements on

Digital Transmission Systems (DTS) Operating Under Part 15.247” [3], chapter 10.2.2.1 is

used.

Table 1. Restricted bands defined in part 15.205

MHz

MHz

MHz

GHz

0.090 – 0.110

16.42 – 16.423

399.9 - 410

4.5 – 5.15

0.495 – 0.505

16.69475 – 16.69525

608 - 614

5.35 – 5.46

2.1735 – 2.1905

16.80425 – 16.80475

960 - 1240

7.25 – 7.75

4.125 – 4.128

25.5 – 25.67

1300 - 1427

8.025 – 8.5

4.17725 – 4.17775

37.5 – 38.25

1435 – 1626.5

9.0 – 9.2

4.20725 – 4.20775

73 – 74.6

1645.5 – 1646.5

9.3 – 9.5

6.215 – 6.218

74.8 – 75.2

1660 - 1710

10.6 – 12.7

6.26775 – 6.26825

108 – 121.94

1718.8 – 1722.2

13.25 – 13.4

6.31175 – 6.31225

123 - 138

2200 - 2300

14.47 – 14.5

8.291 – 8.294

149.9 – 150.05

2310 - 2390

15.35 – 16.2

8.362 – 8.366

156.52475 – 156.52525

2483.5 - 2500

17.7 – 21.4

8.37625 – 8.38675

156.7 – 156.9

2690 - 2900

22.01 – 23.12

8.41425 – 8.41475

162.0125 – 167.17

3260 - 3267

23.6 – 24.0

12.29 – 12.293

167.72 – 173.2

3332 - 3339

31.2 – 31.8

12.51975 – 12.52025

240 - 285

3345.8 - 3358

36.43 – 36.5

12.57675 – 12.57725

322 – 335.4

3600 - 4400

Above 38.6

13.36 – 13.41

Table 2. Radiated and conducted emission limits defined in part 15.209

Frequency

(MHz)

Field strength

(µV/m)

Measurement

distance (m)

Conducted

(dBm)

0.009 – 0.490

2400/f [kHz]

300

0.490 – 1.705

24000/f [kHz]

30

1.705 – 30.0

30

30

-46

30 - 88

100

3

-56

88 - 216

150

3

-52

216 - 960

200

3

-49

960

500

3

-41