Title 47
SECTION 74.536
74.536 Directional antenna required.
§ 74.536 Directional antenna required.(a) Aural broadcast STL and ICR stations are required to use a directional antenna with the minimum beamwidth necessary, consistent with good engineering practice, to establish the link.
(b) An aural broadcast STL or intercity relay station operating in the 17.7-19.7 GHz band shall employ an antenna that meets the performance standards for Category A, except that in areas not subject to frequency congestion, antennas meeting standards for Category B may be employed. However, the Commission may require the replacement, at the licensee's expense, of any antenna or periscope antenna system of a permanent fixed station that does not meet performance Standard A, which is specified in the table in paragraph (c) of this section, upon a showing that said antenna causes or is likely to cause interference to (or receive interference from) any other authorized or proposed station; provided that an antenna meeting performance Standard A is unlikely to involve such interference.
(c) Licensees shall comply with the antenna standards table shown in this paragraph in the following manner:
(1) With either the maximum beamwidth to 3 dB points requirement or with the minimum antenna gain requirement; and
(2) With the minimum radiation suppression to angle requirement.
Antenna Standards
| Frequency (GHz) | Category | Maximum beamwidth
to 3 dB points 1 (included angle in degrees) |
Minimum antenna gain (dbi) | Minimum radiation suppression to angle in degrees from centerline of main beam in decibels | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 5° to 10° | 10° to 15° | 15° to 20° | 20° to 30° | 30° to 100° | 100° to 140° | 140° to 180° | ||||
| 17.7 to 19.7 | A B |
2.2 2.2 |
38 38 |
25 20 |
29 24 |
33 28 |
36 32 |
42 35 |
55 36 |
55 36 |
1 If a licensee chooses to show compliance using maximum beamwidth to 3 dB points, the beamwidth limit shall apply in both the azimuth and the elevation planes.