ULTRA-WIDEBAND VIVALDI ANTENNA ARRAYS WITH TEM HORN

Abstract

Presents the designs and characteristics of antenna array based on the antipodal Vivaldi element.
Antenna arrays with TEM horns of linear and elliptical profile are studied. The parameters of the horns
were optimized. The characteristics were studied in the frequency range from 4 to 12 GHz. The antenna
array with a linear profile TEM horn has the best VSWR in the range from 4 to 5 GHz (for the edge elements
the maximum is 4,75, and 3,33 for others). The operating frequency band of the antenna array is in
the range from 4,90 to 12,00 GHz (overlap coefficient kп=2,45). The frequency characteristics of the realized
gain has dips. The antenna array with a TEM horn of an elliptical profile with a narrow base has a
minimum operating frequency band (from 7,06 to 12,00 GHz (kп=1,70) and a smooth characteristic of the
realized gain. Antenna array with an increased base width of the TEM horn of an elliptical profile has the
best VSWR in the range from 5,3 to 12,0 GHz (for edge elements, the maximum is 2,51, and 2,15 for others),
but the characteristics of the realized gain is smooth only up to 9 GHz. The operating frequency band
of the antenna array is in the range from 4,84 to 12,00 GHz (kп=2,48). The best characteristics has the
antenna array with a TEM horn elliptical profile with an expanded base and increased height. An increase
in the height of the horn leads to an increase in the values of the realized gain at frequencies above
9,25 GHz, where there were dips. The operating frequency band ranges from 4,72 to 12,00 GHz
(kп=2,54). In the operating frequency band, the values of the realized gain are in the range from 11,9 to
20,6 dB. Thus, by choosing the shape and parameters of the horn, the frequency characteristics of the
antenna array can be improved.