IF and associated interface requirements applicable to Satellite Communications SATCOM Earth Terminals ET operating over military X-band and Ka-band Super High Frequency SHF channels. Military unique requirements for ET that may operate over commercial C-band, Ku-band, and Ka-band are included. Equipment developers may exceed the requirements herein to satisfy specific program requirements, provided that interoperability is maintained. Thus, incorporating additional standard and nonstandard capabilities and interfaces is not precluded. Existing SHF SATCOM terminals need not conform to this MIL-STD unless they undergo a modernization program.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59

MIL-STD-188-164B

4.6 Frequency references. If a terminal is capable of accepting an external frequency reference, the terminal shall accept at least one of the following: an external MIL-STD-188-

115 5-MHz frequency reference or an external MIL-STD-188-115 1O-

MHz frequency reference.

For an external frequency reference that is global positioning system (GPS) dependent, that is a GPS Disciplined Oscillator (GPSDO) the following requirements shall apply:

The GPSDO shall be an approved Selective Availability Anti- Spoofing Module SAASM receiver or have the ability for an external time code input i.e. a Defense Advanced GPS Receiver (DAGR) in accordance with GPS-ICD-O6O, and also in STANAG 443O. The external input includes 1PPS, 56 bit/sec time of Day and

Have Quick time code.

The Long Term final RF frequency stability drift (when using a GPSDO) shall not be greater than 1 kHz in a 9O day period without calibration and without GPS aided signal (GPS Antenna disconnected). The Long Term frequency stability drift shall not be greater than 1 kHz in a 9O day period when the GPS aided signal is active.

The stability of the 1OMHz or 5MHz reference source shall have the following Allan Deviation under the following conditions:

t=1 second <1.5E-11 t=1O second <1.5E-11 t=1OO second <1.5E-11 t=1OOO second <1.5E-11

a. These Allan Deviation values shall be met with and without GPS aided signal.

b. On initial GPS receiver turn on (cold start) with the

GPS antenna disconnected; then connected antenna within 1 hour