§ 25.209   Earth station antenna performance standards.

   (a) Except as provided in paragraph (f) of this section, the gain of any
   antenna  to  be  employed in transmission from an earth station in the
   Fixed-Satellite Service shall lie below the relevant envelope defined in
   paragraphs (a)(1) through (4) of this section:

   (1) In the plane of the geostationary satellite orbit as it appears at the
   particular earth station location, for earth stations not operating in the
   20/30 GHz band or conventional Ku-band:
   29-25log10θ dBi For 1.5° ≤θ ≤7°
   8           dBi For 7° <θ ≤9.2°
   32-25log10θ dBi For 9.2° <θ ≤48°
   −10         dBi For 48° <θ ≤180°

   where θ is the angle in degrees from the axis of the main lobe, and dBi
   refers to dB relative to an isotropic radiator. For the purposes of this
   section, the peak gain of an individual sidelobe may not exceed the envelope
   defined above for θ between 1.5 and 7.0 degrees. For θ greater than 7.0
   degrees, the envelope may be exceeded by no more than 10% of the sidelobes,
   provided no individual sidelobe exceeds the gain envelope given above by
   more than 3 dB.

   (2) In the plane of the geostationary satellite orbit as it appears at the
   particular earth station location, for earth stations operating in the 20/30
   GHz band or conventional Ku-band:
   29-25log10θ dBi For 1.5° ≤θ ≤7°
   8           dBi For 7° <θ ≤9.2°
   32-25log10θ dBi For 9.2° <θ ≤48°
   −10         dBi For 48° <θ ≤85°
   0           dBi For 85° <θ ≤180°

   (3) In all other directions, or in the plane of the horizon including any
   out-of-plane  potential  terrestrial interference paths, for all earth
   stations not operating in the 20/30 GHz band or conventional Ku-band:

   Outside the main beam, the gain of the antenna shall lie below the envelope
   defined by:
   32-25log10θ dBi For 3° <θ ≤48°
   −10         dBi For 48° <θ ≤180°

   where θ and dBi are defined above. For the purposes of this section, the
   envelope may be exceeded by no more than 10% of the sidelobes provided no
   individual sidelobe exceeds the gain envelope given above by more than 6 dB.
   The region of the main reflector spillover energy is to be interpreted as a
   single lobe and shall not exceed the envelope by more than 6 dB.

   (4) In all other directions, or in the plane of the horizon including any
   out-of-plane  potential  terrestrial interference paths, for all earth
   stations operating in the 20/30 GHz band or conventional Ku-band:

   Outside the main beam, the gain of the antenna shall lie below the envelope
   defined by:
   32-25log10θ dBi For 3° <θ ≤48°
   −10         dBi For 48° <θ ≤85°
   0           dBi For 85° <θ ≤180°

   where θ and dBi are defined above. For the purposes of this section, the
   envelope may be exceeded by no more than 10% of the sidelobes provided no
   individual sidelobe exceeds the gain envelope given above by more than 6 dB.
   The region of the main reflector spillover energy is to be interpreted as a
   single lobe and shall not exceed the envelope by more than 6 dB.

   (5) Elliptical earth station antennas may be operated only when the major
   axis of the antenna is aligned with the plane of the geostationary satellite
   orbit as it appears at the particular earth station location.

   (b)  Except as provided in paragraph (f) of this section, the off-axis
   cross-polarization gain of any antenna to be employed in transmission from
   an earth station to a space station in the Fixed-Satellite Service shall be
   defined as follows:

   (1) In the plane of the geostationary satellite orbit as it appears at the
   particular earth station location:
   19-25log10θ dBi For 1.8° <θ ≤7°
   −2          dBi For 7° <θ ≤9.2°

   where θ is the angle in degrees from the axis of the main lobe, and dBi
   refers to dB relative to an isotropic radiator.

   (2) In all other directions, or in the plane of the horizon including any
   out-of-plane potential terrestrial interference paths:
   19-25log10θ dBi For 3° <θ ≤7°
   −2          dBi For 7° <θ ≤9.2°

   where θ and dBi are defined above.

   (c)(1) Earth station antennas licensed for reception of radio transmissions
   from a space station in the Fixed-Satellite Service are protected from radio
   interference caused by other space stations only to the degree to which
   harmful interference would not be expected to be caused to an earth station
   employing  an antenna conforming to the referenced patterns defined in
   paragraphs  (a)  and  (b)  of  this  section, and protected from radio
   interference caused by terrestrial radio transmitters identified by the
   frequency  coordination  process  only  to the degree to which harmful
   interference  would  not  be expected to be caused to an earth station
   conforming to the reference pattern defined in paragraphs (a)(3) and (4) of
   this section.

   (2)  17/24 GHz BSS telemetry earth stations are protected from harmful
   interference caused by other space stations to the extent set forth in
   paragraph (c)(1) of this section. Receive-only earth stations in the 17/24
   GHz  BSS are protected from harmful interference caused by other space
   stations to the extent set forth in § 25.224 of this part.

   (d) [Reserved]

   (e) The operations of any earth station with an antenna not conforming to
   the standards of paragraphs (a) and (b) of this section shall impose no
   limitations  upon the operation, location or design of any terrestrial
   station,  any  other  earth station, or any space station beyond those
   limitations  that  would be expected to be imposed by an earth station
   employing  an  antenna conforming to the reference patterns defined in
   paragraphs (a) and (b) of this section.

   (f) An earth station with an antenna not conforming to relevant standards in
   paragraphs  (a) and (b) of this section will be authorized only if the
   applicant  demonstrates  that  the antenna will not cause unacceptable
   interference. For ESVs in the C-band, this demonstration must comply with
   the  procedures  set  forth  in § 25.221. For ESVs in the Ku-band, this
   demonstration must comply with the procedures set forth in § 25.222. For
   VMES, this demonstration shall comply with the procedures set forth in
   § 25.226. For ESAAs, this demonstration shall comply with the procedures set
   forth in § 25.227. For feeder-link earth stations in the 17/24 GHz BSS, this
   demonstration must comply with the procedures set forth in § 25.223. For
   other  FSS  earth  stations,  this  demonstration must comply with the
   requirements in § 25.138, § 25.218, or § 25.220. In any case, the Commission
   will impose appropriate terms and conditions in its authorization of such
   facilities and operations.

   (g) [Reserved]

   (h)(1) The gain of any transmitting gateway earth station antenna operating
   in the 10.7-11.7 GHz, 12.75-13.15 GHz, 13.2125-13.25 GHz, 13.8-14.0 GHz, and
   14.4-14.5 GHz bands and communicating with NGSO FSS satellites must lie
   below the envelope defined as follows:

   29-25log10(θ) dBi for 1° ≤ θ ≤ 36°

   -10 dBi for 36° < θ ≤ 180°

   Where:

   θ is the angle in degrees from the axis of the main lobe, and dBi means dB
   relative to an isotropic radiator.

   (2)  For  the purposes of this section, the peak gain of an individual
   sidelobe may not exceed the envelope defined in paragraph (h)(1) of this
   section.

   [ 48 FR 40255 , Sept. 6, 1983, as amended at  50 FR 2675 , Jan. 18, 1985;  50 FR 39004 , Sept. 26, 1985;  58 FR 13420 , Mar. 11, 1993;  66 FR 10630 , Feb. 16,
   2001;  70 FR 32255 , June 2, 2005;  72 FR 50029 , Aug. 29, 2007;  73 FR 70901 ,
   Nov. 24, 2008;  74 FR 57099 , Nov. 4, 2009;  78 FR 8427 , Feb. 6, 2013;  78 FR 14927 , Mar. 8, 2013;  79 FR 8322 , Feb. 12, 2014]

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