Preliminary Mid-Band Troposcatter Measurement Results Using Different High-Gain Receiver Antennas

This article provides initial results of measurements made to assess the influence that different antenna patterns have on the received signal level of a mid-band troposcatter radio link. Measurements were performed at 3.475 GHz over a 185 km troposcatter link in Colorado with two vertically polarized receiver antennas: standard gain horn and parabolic dish. Median values of basic transmission loss (BTL) are compared for the two antennas. Cumulative distribution functions (CDFs) of hourly median BTL are plotted against predictions from the Institute for Telecommunications Sciences, Irregular Terrain Model (ITM). BTL measurements with the standard gain horn (219.77 dB median and 8.73 dB standard deviation) show better comparison with ITM predictions (214 dB median., and approximately 7.8 dB standard deviation) than BTL measurements made with the parabolic dish (228.21 dB median and 8.67 dB standard deviation). Further measurements and modeling are needed to explain these differences.