Satellite Communications On-the-Move (SOTM)

For FY 2002 the U.S. Army Communications and Electronics Command Space and Terrestrial Communications Directorate was interested in receiving Dual Use Science and Technology (DU S&T) proposals which address innovative, practical, and cost effective technology solutions to the technical barriers associated with satellite communications on-the-move.

The Army has a need for highly directional satellite communication antennas for military and commercial frequency bands for continual connectivity communications on-the-move. Specific bands of current interest include K band GBS (20 GHz), K/Ka band Wideband Gapfiller (20/30 GHz) and K/Q band MILSTAR/Advanced EHF (20/44GHZ). Data rates required are 23 MHz for GBS, 1.544 MB/s for Wideband Gapfiller and low and medium data rate for Advanced EHF (MILSTAR). Spread spectrum modems will be utilized for Wideband Gapfiller to spread the signal to approximately 42 MHz. Wide area "umbrella" coverage will be provided for communications with vehicles on-the-move. With the downsizing of military forces and the Army's reliance on power projection from a largely CONUS-based force, communications on-the-move will become a critical capability for successful and efficient use of military resources in the Future Combat System (FCS).

A phased program is desired which first concentrates on the three beam receive antenna at 20 GHz (K band) for use with GBS, Wideband Gapfiller and Advanced EHF (MILSTAR). The second phase will add a transmit antenna for Wideband Gapfiller (Ka band). The final phase will add the transmit capability for Advanced EHF (MILSTAR) (Q band. A combined transmit antenna for both Ka and Q bands is also acceptable. The Advanced EHF (MILSTAR) antennas should be capable of both low and medium data rate operation. It is incumbent on the offeror to show link budgets which show that the proposed solution will meet the requirements for each system. A full turn key system is required including antenna controllers, Inertial Navigation System and GPS. The controller will be capable of satellite acquisition from satellite ephemeris tables loaded in the system. Acquisition and tracking of three simultaneous beams is required. Transmit beams shall be slaved to received beams.

Desired characteristics of the SOTM antennas include, but should not be limited to:

1. Provides maximum gain with minimal size
2. Mountable on various military vehicles, including HMMWV and Aircraft (C-130)
3. Able to acquire and track a moving (LEO) or fixed (GEO) satellite while military vehicle is stationary or in motion. This may me extendable to Unmanned Aerial Vehicles (UAV's)
4. Ruggedized e.g. able to withstand, harsh environmental conditions
5. Does not increase vehicle vulnerability i.e., low profile
6. Multiband/wideband e.g. 20/30/44 GHz
7. Low Cost Design with maximum use of automatic assembly
8. Use of low cost, low loss phase shifters (thin film ferroelectric, MEMS)

Estimated characteristics required are as follows:

G/T (18.5 to 21.5 GHz) +10 to +12 dB/K
3 simultaneous beams, RHCP and LHCP
(GBS, Wideband Gapfiller, Advanced EHF)

EIRP (27.5 to 31 GHz) +80 dBm
Single beam (Wideband Gapfiller)

EIRP (43.5 to 45.5 GHz) +80 dBm
Single Beam (Advanced EHF)