Engineering topics
Publications and source records attributed to Fujikawa, G..
NASA's vision for science exploration in the next century is based on frequent, affordable missions enabled by small, low-mass, low-cost, highly-autonomous spacecraft. Through the New Millennium Program (NMP), NASA is establishing a new and highly integrated approach to developing and flight-validating technologies that meet these spacecraft goals.
Frequency selective surfaces (FSS's) are often used in spaceborne applications of reflector antennas due to their ability to allow multiple feeds to utilize the same reflector dish. The problems inherent in evaluating the FSS separately from the reflector system are discussed. A method of integrating the FSS effects into the reflector system analysis is presented. An example is given for the proposed Advanced Tracking and Delay Relay Satellite System (ATDRSS) single-access triband reflector antenna.
Four technology development tasks were chosen to reduce (or at least better understand) the technology risks associated with proposed approaches to Advanced Tracking and Data Relay Satellite (ATDRS). The four tasks relate to a Tri-Band Antenna feed system, a Digital Beamforming System for the S Band Multiple Access System (SMA), an SMA Phased Array Antenna, and a Configuration Thermal/Mechanical Analysis task. The objective, approach, and status of each are discussed.
Four technology development tasks were chosen to reduce (or at least better understand) the technology risks associated with proposed approaches to Advanced Tracking and Data Relay Satellite (ATDRS). The four tasks relate to a Tri-Band Antenna feed system, a Digital Beamforming System for the S Band Multiple-Access System (SMA), an SMA Phased Array Antenna, and a Configuration Thermal/Mechanical Analysis task. The objective, approach, and status of each are discussed.
Bit-error-rate tests were performed on a proof-of-concept baseband processor. The BBP, which operates at an intermediate frequency in the C-Band, demodulates, demultiplexes, routes, remultiplexes, and remodulates digital message segments received from one ground station for retransmission to another. Test methods are discussed and test results are compared with the Contractor's test results.