Size Reduction of Omnidirectional Cylindrical Dielectric Resonator Antenna Using a Magnetic Aperture Source

For the first time, an annular slot is used to excite the fundamental TM01 delta mode of a cylindrical dielectric resonator antenna (DRA). The annular slot has eight pairs of meander lines that make the E-field of the slot nearly uniform. The meander lines can introduce an inductance to the antenna and thus, lower the resonant frequency or equivalently reduce the antenna size. To verify the idea, a prototype operating in the fundamental TM01 delta mode was designed, fabricated, and measured for 2.4 GHz WLAN applications (2.40-2.48 GHz). The S-parameters, radiation pattern, realized gain, and total efficiency are simulated and measured, and good agreement between the simulations and measurements is obtained. As compared with a conventional probe-fed TM01 delta-mode cylindrical DRA, our antenna has a size reduction of 43% while providing a measured 10 dB impedance bandwidth of 18.0%.