§  78.105   Antenna systems.

   (a) For fixed stations operating in the 12.7–13.2 GHz and 17.7–19.7 GHz
   bands, the following standards apply:

   (1) Fixed CARS stations shall use directional antennas that meet the
   performance standards indicated in the following table.

   (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) 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.

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

   (A) With either the maximum beamwidth 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 beamwidith 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°
   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 beamwidth 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
   defined in paragraph (a) of this section.

   (4) Pickup stations are not subject to the performance standards herein
   stated. The provisions of this paragraph are effective for all new
   applications accepted for filing after October 1, 1981.

   (b) Any fixed station licensed pursuant to an application accepted for
   filing prior to October 1, 1981, may continue to use its existing
   antenna system, subject to periodic renewal until April 1, 1992, After
   April 1, 1992, all licensees 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 CAR service or TV auxiliary
   broadcast, which shares the 12.7–13.20 GHz band with CARS, 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 require
   conversion 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 § 78.18a was accomplished.

   [ 45 FR 78694 , Nov. 26, 1980, as amended at  49 FR 37779 , Sept. 26, 1984;
    50 FR 7343 , Feb. 22, 1985;  51 FR 19841 , June 3, 1986;  56 FR 50664 , Oct.
   8, 1991;  62 FR 4923 , Feb. 3, 1997;  68 FR 12776 , Mar. 17, 2003]