chapter  5
28 Pages

Antennas with Concentrated Loads

WithBoris Levin

The impedance radiator unlike the metal radiator has additional degrees of freedom. A particular case of the problem is creation of the radiator perpendicular to the radiator axis. Capacitors enable to create along an antenna in a wide frequency range an electromagnetic wave with real propagation constant, which corresponds to the exponential change of the current amplitude with positive decrement. Capacitors enable to create along an antenna in a wide frequency range in-phase current distribution in the form of concave curve. The antenna with distribution, which is close to linear one and is created by capacitances, decreasing to the free end of the antenna in proportion to the distance from it, has a higher matching level and narrower main lobe of the directional pattern. The mathematical programming method allows determining optimal parameters of an antenna, in particular its geometric dimensions, magnitudes of the connected in the antenna concentrated and distributed loads.