--Compact, Multiband, Dual-polarization 20/30/44 GHz Satellite Antenna Feed technical information.

The Space & Terrestrial Communications Directorate (S&TCD) of the Communications, Electronics Research, Development and Engineering Command (CERDEC) intends to make available technical information from Lincoln Laboratory concerning the design of a Co mpact, Multiband, Dual-polarization 20/30/44 GHz Satellite Antenna Feed. This information is available to US-owned businesses only. Interested companies with capabilities to manufacture or use this antenna feed, including small businesses with appropriate machine shop capability, may respond to this announcement. A technical information package, including dimension drawings, will be made available to all qualified respondents. It is anticipated that the technical information package will be available around the end of September 2004. The following information shall be provided by interested organizations as part of their response to this announcement: – Company structure – Company capabilities, including electromagnetic simulation, manufacturing, and measurement capabilities – Related / relevant experience No contract will result from this action in the near future. Please contact Gerald Michael for information. All interested parties should respond ONLY to: Mr. Gerald T. Michael US Army CERDEC S&TCD ATTN: AMSRD-CER-ST-SS-TA (Bldg 210/199) Fort Monmouth, NJ 07703-5302 contact@example.gov Background: The Wideband Tactical Networking Group at MIT Lincoln Laboratory has developed a multiband feed operating at 20/30/44 GHz for insertion into a small communications on the move terminal. The feed provides dual circularly polarized operation in the 20 and 3 0 GHz bands, and RHCP at 44 GHz in a compact form factor. Separation of the various frequency bands is also performed, eliminating the need for external diplexers. The approximate dimensions of the feed are 1 inch in diameter by 5.5 inches long. It cons ists of three components: the primary radiating structure, a 30/44 GHz dual band polarizer, and a 30/44 GHz diplexing orthomode transducer (OMT). Two prototypes have been built and combined with a 16 inch diameter axially displaced elliptical (ADE) reflector. Measured performance is excellent, with 59-69% aperture efficiency at all bands (including all ohmic losses through primary feed, polarizer, and OMT), and axial ratio (averaged over each band) of better than 1 dB. Tri-band capability has been previously developed at C/X/Ku bands (Shea, et al, Method and Apparatus for Transmitting and Receiving Multiple Frequency Bands Simultaneously, U.S. Patent No. 6,329,957) but is not currently available at K/Ka/Q bands using a s ingle feed. The work at Lincoln Laboratory was performed to address this need. Several new concepts were developed in order to accomplish this task, including a tapered dielectric hybrid mode junction and a wideband dielectrically loaded polarizer. This allows tri-band operation through a common unloaded circular waveguide section that operates in the fundamental mode at 20 and 30 GHz, but is overmoded at 44 GHz. The measured characteristics of the current Lincoln Laboratory prototype are as follows: Feed: Frequency bands: 20.2-21.2 GHz, 30.0-31.0 GHz, 43.5-45.5 GHz Return Loss greater than 15 dB over all bands 20 GHz RHCP/LHCP isolation: greater than 14.5 dB 30 GHz RHCP/LHCP isolation: greater than 18 dB 20/30 GHz isolation: greater than 60 dB at each receive port 20/45 GHz isolation: greater than 55 dB at each receive port Reflector: Gain: 36.6 dBi @ 20.7 GHz 40.2 dBi @ 30.5 GHz 43.9 dBi @ 44.5 GHz Axial Ratio: 1 dB