Study of high temperature antennas for HOPE communication/data processing system, part 4-A

This report describes design and characteristics of heat-resistant antennas supplied in communication and data processing system of H-2 Orbiting Plane (HOPE). In antenna design, the following were reviewed: (1) mode, number and arrangement of antennas required for system operation and spacecraft; (2) polarization mode of TVTX (Television Transmitter) antenna; (3) high-amplification USB (Upper Side Band) antenna; and (4) extensive coverage of GPSR (Global Positioning System Receiver), C/RT (C Band-Radar Transponder) and USB antenna. For materials composing heat-resistant antenna, thermal characteristics of dissolving silica and mullite were studied to determine thermoconductivity and heat capacity in vacuum. For heat resistance of power supply component, conventional SMA (S-Band Multiple Access) connector available up to 125 C was modified to be able to be used in high temperature, and the performance was evaluated at 200 C. As a result, the modified connector was proved to be available in the range of - 80 to 200 C. On the basis of these results, new connector available up to 300 C is planning to be developed.