Aperture coupling near-field cavity effects for electromagnetic testing with measurements on a slotted circular cylinder

Electric field measurements for an electromagnetic wave excited from a log-periodic dipole array at two separation distances on a finite slotted circular cylinder are compared to an analytical model of a plane wave on an infinite slotted circular cylinder. The four foot diameter cylinder cross section is used to represent the cross section (1/2 scale) of an Army Blackhawk helicopter. The frequency range of interest is in the Very High Frequency (VHF) band where the first resonances of the cavity occur. Transverse Magnetic (TM) and Transverse Electric (TE) polarizations are considered.