Accession Number : ADA254736


Title :   Extension of Fresnel Near-Field Region by Single-Cycle Sinusoidal Pulses


Descriptive Note : Interim rept.


Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC


Personal Author(s) : Samaddar, S N


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254736.pdf


Report Date : 21 Aug 1992


Pagination or Media Count : 55


Abstract : A circular conducting disk antenna is excited by three uniform current waveforms namely, a very high frequency CW sin& , a single-cycle sinwO1, and a single-cycle coswOt. The energy per cycle associated with each of these waveform is taken to be the uM. From the behavior of the radiated energy densities along the axis of the disk, it is found that if the CW waveform extends the near field to unit distance, then the corresponding distances are 1. 375 and 3.75 for the single-cycle sinwOt and the single-cycle coswOt respectively. These results show that the method of energy transfer to a large distance along the axis of an aperture (or disk) becomes more efficient when a short pulse, instead of a CW source, is applied. This will have applications wherever a transmission of high intensity beam of energy far away from a radiating device is needed.


Descriptors :   *DISKS , *NEAR FIELD , *SHORT PULSES , *DIRECTIONAL ANTENNAS , FREQUENCY , DENSITY , HIGH FREQUENCY , ENERGY , WAVEFORMS , INTENSITY , TRANSFER , APERTURES , FRESNEL ZONES , UNIFORMS , CIRCULAR , VERY HIGH FREQUENCY , HIGH INTENSITY , ENERGY TRANSFER , CYCLES , REGIONS , PULSES , ANTENNAS , BEHAVIOR


Subject Categories : Electrical and Electronic Equipment
      Radiofrequency Wave Propagation


Distribution Statement : APPROVED FOR PUBLIC RELEASE