Functional/Thermal verification and validation of an S-Band radio for the nanosatellites

Abstract

An S-band radio designed with commercial-grade components for the nanosatellites is functionally and thermally characterized for quiet transmission. The QPSK modulation impairments are minor over −20 °C to +50 °C at 24, 26, 28 and 30 dBm RF levels. The channel response is linear in error vector magnitude, frequency, phase, amplitude and IQ errors. On the average, the stability of amplifier bias and nonlinearity gives −22 dBc maximum upper/lower adjacent channel power and 1.27 MHz occupied channel bandwidth. The acceptable level test results provide good confidence toward robust space-to-earth transmission in variable solar weather at low earth orbital altitudes.