Department of Commerce, NOAA, SAO4, 1315 East West Highway, Rm. 9608, Silver Spring, M/d

A -- TECHNOLOGY READINESS FOR MILLIMETER-WAVE ANTENNAS AND MMIC RECEIVERS FOR THE GOES FUTURE REQUIREMENTS. SOL 53-SPNA-6-00021 DUE 101996 POC Dr. Ed Howard, 301-7130098 NOAA (National Oceanic and Atmospheric Administration) seeks early information from industry, academic and other agencies about technology readiness for a passive microwave radiometer that could fly on future GOES (Geosynchronous Operational Environmental Satellites). This call is for information purposes only. The government does not intend to award any contracts based on this action or to pay any costs associated with this information. This procurement is subject to review and cancellation at any time. Early discussion has lead totechnical questions as stated in the three paragraphs below towhich we seek answers. The objective of this release is to allow industry and others the opportunity to verify the reasonableness and feasibility of the requirements to date. Prospective offerors are invited to submit comments to the questions belowalong with a 5-10 page capability statement demonstrating the irrelevant experience, familiarity with the appropriate technology, experienced personnel, and plant facilities/equipment. Interested firms are requested to submit information within three weeks of this release. It is anticipated that selected firms will be invited from those responding to meet in Silver Spring, MD for a full day meeting in October, 1996. Both open forum andprivate discussions may follow between the firms and a microwave study committee. Please send responses to: NOAA/SAO4, 1315 East-West Highway, Silver Spring, MD 20910, Attn: Dr. Ed Howard. Additional inquires should be directed to Dr. Ed Howard, preferably by fax to (301) 713-4153. 1. What is the likely availability and cost dependencies on antenna diameter and beam efficiency of on-axis and off-axis fedparabolic antennas for frequencies from 100 to 430 GHz? Beam efficiencies greater than 95% within a radius equal to 1.5 times the 3-db beamwidth are of particular interest for antennas with diameters between 1.5 and 4 meters; far sidelobes beyond 20 degrees are of less concern. Four bands will be used simultaneously on one antenna: 112-122; 170-186, 360-390, and 410-430 GHz. The antenna could be mounted on a 3-axis stabilized geostationary satellite. Is it difficult to achieve diffraction-limited beamwidths and high beam efficiencies at all four bands simultaneously if the four beams are coaxial? If they are slightly offset linearly? Over what angle (angles of a few milliradians are probably sufficient) could a nodding subreflector (or equivalent means) scan the four beams along one axis without significantly sacrificing beam efficiencies or system costs? Are there effective radiometer calibration systems that can be used with these antennas at intervals of a few seconds? 2. What scan rates and raster-scan turnaround delays can readily be achieved without serous degradation of beam efficiencies orsacrifice of pointing accuracy? Can pointing accuracies of one-tenth beamwidth reasonably be achieved? How does cost vary withpointing accuracy? How does cost vary with scan acceleration and scan rate if beam efficiencies and pointing accuracies are approximately maintained? What sort of momentum compensation can be achieved at modest cost? How much might such an antenna and scan system weigh if it were to raster scan at 1 to 10 degrees per minute? 3. What sort of receiver noise figures and bandwidth are reasonable to expect in the year 2002 for these frequencies? For which frequency bands are MMIC's or other RF amplifiers likely to be used, and of what type? What type of receiver detection systems would be preferred if RF amplifiers were not used above130 GHz, and what would be the likely noise figures? Each receiver might split out 8 channels over an i.f. bandwidth of 3-15 GHz, where the channel widths might vary from 30 MHz to 3 GHz within each band; how might receiver cost vary with the number of such detected channels per band and what technologies would be preferred for implementing such filtering and detection systems? (0227)

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