Specific examples of Ka-band research from SCaN Testbeds first year of operation will be cited, such as communications link performance with TDRSS, and the effects of truss flexure on antenna pointing. The potential for high rate data transfer can also be extended for direct-to-ground links through use of variable or adaptive coding and modulation.
Unlike at S-band, a larger bandwidth may be available for space missions, allowing increased data rates. Ka-band provides a number of technical advantages for bulk data transfer. Additionally, the antenna pointing routines require enhanced knowledge of spacecraft position and attitude for initial acquisition, versus an S-band antenna. The smaller antenna beamwidth at Ka-band increases the criticality of antenna pointing, necessitating closed loop tracking algorithms and new techniques for received power estimation. Pass Band Frequency: 19.7 - 20.2 GHz: Reject Band Frequency: 25 - 31 GHz: Polarity: Linear: Return Loss: 15 dB: Insertion Loss: 0.3 dB: Rejection: 25 dB 25 GHz 40 dB 30 GHz: Flange for connections: WR42: Weight: 40 g: Dimensions: 22.4 x 22.4 x 40. A number of technical areas need to be addressed for successful transition to Ka-band. Over the past year, SCaN Testbed has demonstrated Ka-band communications capabilities with NASAs Tracking and Data Relay Satellite System (TDRSS) using both open- and closed-loop antenna tracking profiles. The testbed contains two S-band SDRs and one Ka-band SDR. NASAs Space Communications and Navigation (SCaN) Testbed provides a software-defined radio (SDR) platform that is capable of supporting investigation of this service transition.
Studying nasa's transition to ka-band communications for low earth orbit As the S-band spectrum becomes crowded, future space missions will need to consider moving command and telemetry services to Ka-band.
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