§  74.641   Antenna systems.

   (a) For fixed stations operating above 2025 MHz, the following
   standards apply:

   (1) Fixed TV broadcast auxiliary stations shall use directional
   antennas that meet the performance standards indicated in the following
   table. Upon adequate showing of need to serve a larger sector, or more
   than a single sector, greater beamwidth or multiple antennas may be
   authorized. Applicants shall request, and authorization for stations in
   this service will specify, the polarization of each transmitted signal.
   Booster station antennas having narrower beamwidths and reduced
   sidelobe radiation may be required in congested areas, or to resolve
   interference problems.

   (i) Stations must employ an antenna that meets the performance
   standards for Category B. In areas subject to frequency congestion,
   where proposed facilities would be precluded by continued use of a
   Category B antenna, a Category A antenna must be employed. The
   Commission may require the use of a high performance antenna where
   interference problems can be resolved by the use of such antennas.

   (ii) Licensees shall comply with the antenna standards table shown in
   this paragraph in the following manner:

   (A) With either the maximum beamwith to 3 dB points requirement or with
   the minimum antenna gain requirement; and

   (B) With the minimum radiation suppression to angle requirement.

   Antenna Standards
   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°
   1,990 to 2,110 A
   B 5.0
   8.0 n/a
   n/a 12
   5 18
   18 22
   20 25
   20 29
   25 33
   28 39
   36
   6,875 to 7,125 A
   B 1.5
   2.0 n/a
   n/a 26
   21 29
   25 32
   29 34
   32 38
   35 41
   39 49
   45
   12,700 to 13,250 A
   B 1.0
   2.0 n/a
   n/a 23
   20 28
   25 35
   28 39
   30 41
   32 42
   37 50
   47
   17,700 to 19,700 A
   B 2.2
   2.2 38
   38 25
   20 29
   24 33
   28 36
   32 42
   35 55
   36 55
   36

   ^1If a licensee chooses to show compliance using maximum beamwith to 3
   dB points, the beamwidth limit shall apply in both the azimuth and the
   elevation planes.

   (2) New periscope antenna systems will be authorized upon a
   certification that the radiation, in a horizontal plane, from an
   illuminating antenna and reflector combination meets or exceeds the
   antenna standards of this section. This provision similarly applies to
   passive repeaters employed to redirect or repeat the signal from a
   station's directional antenna system.

   (3) The choice of receiving antennas is left to the discretion of the
   licensee. However, licensees will not be protected from interference
   which results from the use of antennas with poorer performance than
   identified in the table of this section.

   (4) [Reserved]

   (5) Pickup stations are not subject to the performance standards herein
   stated.

   (b) All fixed stations are to use antenna systems in conformance with
   the standards of this section. TV auxiliary broadcast stations are
   considered to be located in an area subject to frequency congestion and
   must employ a Category A antenna when:

   (1) A showing by an applicant of a new TV auxiliary broadcast station
   or Cable Television Relay Service (CARS) station, which shares the
   12.7–13.20 GHz band with TV auxiliary broadcast, indicates that use of
   a category B antenna limits a proposed project because of interference,
   and

   (2) That use of a category A antenna will remedy the interference thus
   allowing the project to be realized.

   (c) As an exception to the provisions of this section, the FCC may
   approve requests for use of periscope antenna systems where a
   persuasive showing is made that no frequency conflicts exist in the
   area of proposed use. Such approvals shall be conditioned to a standard
   antenna as required in paragraph (a) of this section when an applicant
   of a new TV auxiliary broadcast or Cable Television Relay station
   indicates that the use of the existing antenna system will cause
   interference and the use of a category A or B antenna will remedy the
   interference.

   (d) As a further exception to the provision of paragraph (a) of this
   section, the Commission may approve antenna systems not conforming to
   the technical standards where a persuasive showing is made that:

   (1) Indicates in detail why an antenna system complying with the
   requirements of paragraph (a) of this section cannot be installed, and

   (2) Includes a statement indicating that frequency coordination as
   required in § 74.604 (a) was accomplished.

   [ 45 FR 78693 , Nov. 26, 1980, as amended at  49 FR 7131 , Feb. 27, 1984;
    49 FR 37778 , Sept. 26, 1984;  50 FR 7342 , Feb. 22, 1985;  51 FR 19840 ,
   June 3, 1986;  52 FR 7143 , Mar. 9, 1987;  55 FR 11587 , Mar. 29, 1990;  56 FR 50663 , Oct. 8, 1991;  62 FR 4922 , Feb. 3, 1997;  68 FR 12771 , Mar. 17,
   2003]