Dispersion in the 10-30 GHz Frequency Range: Atmospheric Effects and Their Impact on Digital Satellite Communications

Earth-space communications links operating above 10 GHz may be adversely affected by the earth´s atmosphere and hydrometeors, particularly rain. These propagation phenomena are usually evaluated only for fading and depolarization effects. However, dispersion is an important factor in wide-band digitally modulated satellite links. In this paper we examine the mechanisms responsible for dispersion over bandwidths as great as 500 MHz in the 10-30 GHz range. The amplitude and phase effects of dispersion are quantified for a wide range of propagation conditions. The resulting propagation model is then used to generate estimates of performance degradation in wide-band QPSK systems through the use of computer simulation.