, a log-periodic antenna
(LP) is a broadband, multielement, unidirectional, narrow-beam antenna
that has impedance
characteristics that are regularly repetitive as a logarithmic function of the excitation frequency
Note: The length and spacing of the elements of a log-periodic antenna increase logarithmically from one end to the other. Synonym log-periodic array.
Source: from Federal Standard 1037C and from MIL-STD-188