Impedance Characteristics of a Cylindrical Dielectric Resonator Antenna Excited by Slot

In order to facilitate broadband communications, use of the millimeter wave frequencies has recently been discussed. One of the millimeter wave antennas is a dielectric resonator antenna (DRA). In this paper, with a view to using a DRA at millimeter wave frequencies, the dimensions and permittivity of the cylindrical DRA excited by a slot affecting the impedance characteristics are analyzed. With regard to the effect of the dimensions, the impedance characteristics versus the radius and height of the DRA are studied. With regard to the permittivity, the relative permittivity of the DRA is varied from 1 to 64 in the analysis. A broadband characteristic is achieved by selecting the relative permittivity in the range of 4 to 16 while the radius of the dielectric resonator is 0.35 wavelength and the slot length is 0.5 wavelength. As an example, broadbanding is attempted with a VSWR of less than 2 when the relative permittivity is 10. The relative bandwidth obtained by numerical analysis was 28.8%, whereas that obtained by experiment was 34.6%. (c) 2006 Wiley Periodicals, Inc.