Small Frequency Ratio Multi-Band Dielectric Resonator Antenna Utilizing Vertical Metallic Strip Pairs Feeding Structure

In this study a quintuple band rectangular dielectric resonator antenna (RDRA) with a small frequency ratio and small size of 30 mm × 30 mm × 9.813 mm is introduced. The proposed RDRA covers the frequency bands of WLAN (2.4/5.2 GHz), WiMAX (3.5 GHz) and 5G (4.1/4.8 GHz) exploiting TE
₁₀
^y
, TE
₂₁₁
^x
, TE
_1δ1
^y
, TE
₁₁₁
^y
, and TE
_2δ1
^y
modes, respectively. A rectangular slot aperture is optimized to serve as a resonator with resonance mode TE
₁₀
^y
as well as to couple the electric field from microstrip line to the DRA to excite TE
₂₁₁
^x
mode. Furthermore, a new feeding approach employing three vertical metallic strip pairs (VMSPs) is proposed to excite further TE
_1δ1
^y
, TE
₁₁₁
^y
, and TE
_2δ1
^y
modes in the RDRA. The VMSPs are configured on both sides of the dielectric resonator (DR) along the y - direction to act as vertical electric current sources. The lengths, width, and positions of the VMSPs are carefully determined in order to attain the desired modes. The four RDRA modes have broadside patterns while the slot resonator mode has a pattern like a dipole. Good agreement between both measured and simulated results of the reflection coefficient, radiation pattern, and the gain is achieved.