Effect of aperture matching on the performance of tem horn antenna

TEM horn antennas are widely used in ultra wide band (UWB) radar and UWB communication applications due to its wide bandwidth and non-dispersive characteristic. Linearly tapered constant impedance TEM horn is most commonly used variation of TEM horn due to its simplicity and ease of fabrication. In many practical systems cylindrical sections are added at the aperture of TEM horn to improve its low frequency performance. This paper discusses the effect of aperture matching on the 45 cm long TEM horn (0.8 – 7 GHz). Effect on the performance of TEM horn is analyzed in terms of reflection coefficient, boresight gain of TEM horn, energy pattern and peak power pattern of TEM horn in E&H planes. CST microwave studio was used for the modeling and analysis of antennas.