Echo analysis of side-mounted DTV broadcast antenna azimuth patterns

Azimuth pattern analysis of a side-mounted antenna is made keeping reflections separate from the main radiated signal. Each reflection is characterized by a reflection coefficient and path difference in wavelengths at a distant receiving summing point. At each azimuth, the reflections are expressed as echoes accompanying a modulated VSB data pulse. The corresponding receiver equalizer tap weights are determined from which the DTV receiver threshold impact is calculated. Measurements of a side-mounted antenna using an azimuth fly-around technique are compared to the calculated results for specific azimuth directions. It is concluded that the DTV performance degradation caused by close-in reflections from adjacent tower members may be predicted by calculation and that the degradation is small.