Accession Number : AD0648718

Title :   HARMONIC ANALYSIS OF A HALF-WAVE DIPOLE AND DIRECTOR PARALLEL TO A REFLECTING PLANE.

Descriptive Note : Interim technical rept.,

Corporate Author : PENNSYLVANIA UNIV PHILADELPHIA MOORE SCHOOL OF ELECTRICAL ENGINEERING

Personal Author(s) : Goldhirsh,J. ; Lombardini,P. P.

Report Date : FEB 1967

Pagination or Media Count : 37

Abstract : When substantial harmonic power exists at the input of a radiating antenna, a lobe structure will result that may create a substantial interference problem. In addition, the privacy of the radiating source may be severely hampered. These harmonic fields are generally dependent upon: (a) The order of the harmonic relative to the geometry of the antenna. (b) The impedance the higher harmonic 'sees' at the antenna input. (c) The power available at the given harmonic. The purposes of providing a measure of the seriousness of this problem, a harmonic analysis of a particular type of antenna configuration is examined, namely, that of a center-fed, thin half-wave dipole with director parallel to a reflecting plane. The active dipole is assumed lambda sub 0/4 away from the reflecting plane and the director lambda sub 0/8 away from the active dipole. As a criterion to determine the 'worst case' situation, the antenna is assumed matched at each odd harmonic examined, and equal power is assumed fed at the input. The resulting field patterns show: (a) The presence of the director results in the introduction of sidelobes at the fundamental frequency in the azimuthal plane. (b) The presence of the director plays less of a role the higher the harmonic. (c) In the meridian plane the sidelobes become more intense exceeding the forward lobe intensity as the order of the harmonics is increased. (d) In the azimuthal plane, the sidelobe intensity approaches but does not exceed the forward lobe intensity. (Author)

Descriptors :   (*DIPOLE ANTENNAS, HARMONIC ANALYSIS), ANTENNA RADIATION PATTERNS, THEORY, GAIN, ANTENNA COMPONENTS, OPTIMIZATION

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE