§  30.406   Directional antennas.

   (a) Unless otherwise authorized upon specific request by the applicant,
   each station authorized under the rules of this subpart must employ a
   directional antenna adjusted with the center of the major lobe of
   radiation in the horizontal plane directed toward the receiving station
   with which it communicates: provided, however, where a station
   communicates with more than one point, a multi- or omni-directional
   antenna may be authorized if necessary.

   (b) Fixed stations (other than temporary fixed stations) must employ
   transmitting and receiving antennas (excluding second receiving
   antennas for operations such as space diversity) meeting the
   appropriate performance Standard A indicated in the table to this
   section, except that in areas not subject to frequency congestion,
   antennas meeting performance Standard B may be used. For frequencies
   with a Standard B1 and a Standard B2, in order to comply with Standard
   B an antenna must fully meet either Standard B1 or Standard B2.
   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.
   Frequency
   (MHz) 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°
   38,600 to 40,000^2 A n/a 38 25 29 33 36 42 55 55
       B n/a 38 20 24 28 32 35 36 36

   ^1If 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.

   ^2Stations authorized to operate in the 38,600-40,000 MHz band may use
   antennas other than those meeting the Category A standard. However, the
   Commission may require the use of higher performance antennas where
   interference problems can be resolved by the use of such antennas.