An investigation of the design of a log-periodic dipole array with low side-lobe levels for broadcast applications

The problem of cochannel interference is addressed. The ability of the Numerical Electromagnetics Code (NEC2) computer program to predict the radiation pattern of an antenna array on a mast is investigated. The evaluation and validation of NEC2 is undertaken by the comparison of measured and computed radiation patterns of log-periodic dipole antenna arrays. Emphasis is placed on the correspondence of the side-lobe levels -30 to -40 dB down from the main lobe. This is important in the synthesis of an array with predictable null positions and depths