(a) 2025-2110 MHz. For frequencies offset from the assigned frequency less than the 50 percent of the necessary bandwidth, no attenuation is required. At a frequency offset equal to 50 percent of the necessary bandwidth, an attenuation of at least 8 dB is required. Frequencies offset more than 50 percent of the necessary bandwidth shall be attenuated by the following mask:
Equation 1 to Paragraph (a)
Where:
fd is the frequency displaced from the center of the emission bandwidth.
Bn is the necessary bandwidth, which is determined in accordance with Annex J of the NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management (NTIA Manual) (incorporated by reference, see § 26.305).
dBsd is dB attenuation in a 4 kHz bandwidth, relative to the maximum power in any 4 kHz bandwidth within the necessary bandwidth (0 dBsd), where attenuation in this sense refers to the reduction in level relative to the reference, 0 dBsd, unless otherwise specified.
The unwanted emission mask rolls off at 40 dB per decade to a maximum attenuation of 60 dBsd, at which point it continues on both sides of the carrier for all frequencies beyond this point; see Annex M of the NTIA Manual regarding measurement requirements (incorporated by reference, see § 26.305); for any narrowband or single frequency unwanted emission which is not spread by the modulation process, the required attenuation shall be at least 60 dBc, where dBc is attenuation below the mean transmit power, rather than the dBsd value determined in equation 1 to this paragraph (a).
(b) 2200-2290 MHz. (1) During the first stage of a launch, all spectral components larger than −[55 + 10xlog(P)] dBc (i.e., larger than −25 dBm) at the transmitter output must be within the spectral mask calculated using the following equation:
Equation 2 to Paragraph (b)(1)
M(f) = K + 90 log(R)−100 log |f-fc|; |f-fc| ≥ R/m
Where:
M(f) = power (dBc) at frequency f (MHz).
K = −20 for analog signals.
K = −28 for binary signals.
K = −61 for FQPSK-B, FQPSK-JR, SOQPSK-TG.
K = −73 for ARTM CPM.
fc = transmitter center frequency (MHz).
R = bit rate (Mbps) for digital signals or (Δf +fmax)(MHz) for analog FM signals.
M = number of states in modulating signal (m = 2 for binary signals, m = 4 for quaternary signals and analog signals).
f = peak deviation.
fmax = maximum modulation frequency.
(2) After the first stage of a launch, the emission mask set forth in paragraph (a) of this section shall apply.
(c) 2360-2395 MHz. (1) When using frequency modulation or digital modulation for telemetry or telecommand with an authorized bandwidth equal to or less than 1 MHz the emissions must be attenuated as follows:
(i) On any frequency removed from the assigned frequency by more than 100 percent of the authorized bandwidth up to and including 100 percent plus 0.5 MHz, the attenuation must be at least 60 dB, when measured in a 3.0 kHz bandwidth. This signal need not be attenuated more than 25 dB below 1 milliwatt.
(ii) On any frequency removed from the assigned frequency by more than 100 percent of the authorized bandwidth plus 0.5 MHz, the attenuation must be at least 55 + 10 log10 pY dB when measured in a 3.0 kHz bandwidth.
(2) When using frequency modulation or digital modulation for telemetry or telecommand with an authorized bandwidth greater than 1 MHz, the emissions must be attenuated as follows:
(i) On any frequency removed from the assigned frequency by more than 50 percent of the authorized bandwidth plus 0.5 MHz up to and including 50 percent of the authorized bandwidth plus 1.0 MHz, the attenuation must be 60 dB, when measured in a 3.0 kHz bandwidth. The signal need not be attenuated more than 25 dB below 1 milliwatt.
(ii) On any frequency removed from the assigned frequency by more than 50 percent of the authorized bandwidth plus 1.0 MHz, the attenuation must be at least 55 + 10 log10 pY dB, when measured in a 3.0 kHz bandwidth.
[90 FR 11493, Mar. 7, 2025]
(a) 2025-2110 MHz. The equivalent isotropically radiated power (EIRP) transmitted in any direction towards the horizon by an earth station in the 2025-2110 MHz band of the Space Launch Services shall not (with limited exceptions) exceed the following limits:
(1) +40 dBW in any 4 kHz band for u ≤0°;
(2) +40+3u dBW in any 4 kHz band for 0°< u ≤5°; and
(3) Where u is the angle of elevation of the horizon viewed from the center of radiation of the antenna of the earth station and measured in degrees as positive above the horizontal plane and negative below it.
(b) 2200-2290 MHz. During the first stage of a launch, the EIRP of any station in the 2200-2290 MHz band of the Space Launch Services shall not exceed 25 Watts and the transmitter output power shall not exceed 25 Watts. In addition, the power flux-density at the Earth's surface produced by emissions from a transmitter operating after the first stage of a launch for all conditions and for all methods of modulation shall not exceed the following limits:
(1) −154 dB(W/m2) in any 4 kHz for angles of arrival less than 5° above the horizontal plane;
(2) −154 + 0.5 (δ−5) dB(W/m2) in any 4 kHz for angles of arrival δ (degrees) between 5° and 25° above the horizontal plane; and
(3) −144 dB(W/m2) in any 4 kHz for angles of arrival between 25° and 90° above the horizontal plane.
(c) 2360-2395 MHz. The EIRP of any station in the 2360-2395 MHz band of the Space Launch Services shall not exceed 25 Watts and the transmitter output power shall not exceed 25 Watts. Transmitter power may be increased to overcome line and duplexer losses but must not exceed 25 Watts delivered to the antenna.
[89 FR 63321, Aug. 5, 2024, as amended at 90 FR 11493, Mar. 7, 2025]
Certain material is incorporated by reference into this subpart with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. All approved incorporation by reference (IBR) material is available for inspection at the Federal Communications Commission (FCC) and at the National Archives and Records Administration (NARA). Contact the FCC at the address indicated in § 0.401(a) of this chapter; phone: (202) 418-0270; email: [email protected]. For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected]. The material may be obtained from National Telecommunications and Information Administration (NTIA), Office of Spectrum Management, 1401 Constitution Avenue NW, Room 1087, Washington, DC 20230; phone (202) 482-1850; website: www.ntia.gov/office/office-spectrum-management-osm:
(a) NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, Annex J: Guidance for Determination of Necessary Bandwidth, NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, January 2023 Revision (of the January 2021 Edition); IBR approved for § 26.302. (Available at www.ntia.gov/sites/default/files/2023-11/j_2021_edition_rev_2023.pdf.)
(b) NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management, Annex M: Measurement Methods, January 2023 Revision (of the January 2021 Edition); IBR approved for § 26.302. (Available at www.ntia.gov/sites/default/files/2023-11/m_2021_edition_rev_2023.pdf.)