Abstract
This paper outlines the design and development of a VHF / UHF communications system for application in small satellites in LEO orbit. Based on the VHF / UHF transceiver as used in the Delfi-C3 nanosatellite, the transceiver presented in this paper features full duplex capability by providing a VHF Binary Phased Keying (BPSK) downlink up to 9600 bit/s and a UHF Frequency Shift Keying (FSK) uplink up to 9600bit/s. Lower datarates can be accommodated as well. It is usable over a wide frequency range, allowing both the amateur radio and commercial frequency bands to be used. The entire transceiver is housed on a single Printed Circuit Board of 90 x 96mm, making it possible to apply the transceiver as a low rate telemetry / telecommand transceiver in spacecraft ranging from nanosatellites to microsatellites. The transmitter section includes a class E nonlinear power amplifier of which the supply voltage is modulated with envelope information in order to allow for processing of non-constant envelope (shaped) BPSK modulation while maintaining both high power and spectral efficiency. This paper discusses the design and development of the VHF / UHF transceiver, the protocol used and the accompanying ground station software defined demodulation system. Special attention is given to the design methodology used.
Presentation Slides
A Miniaturized Nanosatellite VHF / UHF Communications System
This paper outlines the design and development of a VHF / UHF communications system for application in small satellites in LEO orbit. Based on the VHF / UHF transceiver as used in the Delfi-C3 nanosatellite, the transceiver presented in this paper features full duplex capability by providing a VHF Binary Phased Keying (BPSK) downlink up to 9600 bit/s and a UHF Frequency Shift Keying (FSK) uplink up to 9600bit/s. Lower datarates can be accommodated as well. It is usable over a wide frequency range, allowing both the amateur radio and commercial frequency bands to be used. The entire transceiver is housed on a single Printed Circuit Board of 90 x 96mm, making it possible to apply the transceiver as a low rate telemetry / telecommand transceiver in spacecraft ranging from nanosatellites to microsatellites. The transmitter section includes a class E nonlinear power amplifier of which the supply voltage is modulated with envelope information in order to allow for processing of non-constant envelope (shaped) BPSK modulation while maintaining both high power and spectral efficiency. This paper discusses the design and development of the VHF / UHF transceiver, the protocol used and the accompanying ground station software defined demodulation system. Special attention is given to the design methodology used.
