Independent Matching Dual-Band Compact Quarter-Wave Half-Slot Antenna for Millimeter-Wave Applications

A dual-band mm-wave compact antenna is proposed in this paper. A quarter-wave half-slot resonator is used instead of a half-wave slot to achieve miniaturization of the antenna size. The antenna consists of two stacked half-slot resonators to radiate at two frequencies, f
₁
= 24 GHz and f
₂
= 28.5 GHz, with the same microstrip line feed. By using this stacked structure, a dual-band is obtained and the two resonant frequencies become independently matched with a minor effect on each other. Measurements show the proposed antenna has an impedance bandwidths of 6.3% and 15% at f
₁
and f
₂
, respectively; furthermore, the antenna has good radiation characteristics. The antenna gains in addition to the radiation efficiencies at f
₁
and f
₂
, are 3.5dBi, 92%, 4dBi, and 95% respectively. The equivalent circuit model for the proposed antenna is introduced to show the electrical behavior of the antenna. Finally, the antenna design is inserted in multiple-input multiple-output (MIMO) system. The proposed antenna is analyzed and optimized using ANSYS HFSS EM simulator and its equivalent circuit is performed by Agilent Advanced Design System (ADS). The simulated as well as measured results show good agreement. The designated antenna resembles good candidate for 5G wireless communication systems.