ABSTRACT
This article describes the design and fabrication of a 4 × 4 MIMO antenna array intended for operation at 60 GHz. The antenna comprises of half-circular p-shaped radiator connected with a microstrip line printed on the Rogers 4003 substrate of area 22.5 × 22.5 mm2 with εr, thickness, and tan δ of 3.5, 0.203 mm, and 0.0027, respectively. This single radiator is doubled and connected to the power divider to obtain a 1 × 2 antenna array for gain enhancement purposes. The array model is duplicated on the same substrate to achieve 2 ports and 4 ports MIMO antenna. Thereafter, the model is experimentally fabricated and tested to validate the simulated results. The measured results demonstrate the antenna's 60 GHz operating bandwidth extended from 57 GHz to 63 GHz and with insertion losses ≤ -30 dB between ports (1,2) and (1,4) (the orthogonal ports), while it equals around ≤ -23 dB between ports (1,3) (the mirrored ports) within the achieved band with good consistency between both simulated and tested results. Also, it has achieved a gain of more than 9 dBi at 60 GHz with a broadside radiation pattern in both planes. Furthermore, the MIMO parameters are also carried out (ECC, DG, CCL, MEG, and TARC). The ECC is below 0.0025, the DG is approximately 10 dB, the CCL is below 0.2 bits/s/Hz, the MEG is -3 dB and the TARC is below -10 dB over the achieved frequency band. All the MIMO parameters are investigated to prove the diversity characteristics of the antenna array which supports the antenna to be suitable for the 60 GHz communication.
ABSTRACT
A circularly polarized (CP) and wide-band monopole antenna with a miniaturized size is suggested in this study. The suggested structure is composed of a U-shaped radiator on the front side, a partial ground plane with two rectangle slots, and a quadrilateral-shaped parasitic strip on the back side of the FR4 substrate. A wide-band operation with S11 ≤ -10 dB was achieved by regulating the radiator and the partial ground that was placed on the second side of the antenna substrate. The CP was achieved when excited two modes with the same amplitude and a 90° phase difference. This could be generated by regulating the slots' dimensions in the ground plane. Moreover, a quadrilateral-shaped parasitic strip placed on the second side with the partial ground was utilized to extend the 3 dB axial ratio (AR) bandwidth. The suggested structure is simulated, prototyped, and measured to confirm the desired requirements with a total size of 30 × 32 mm2 (0.4 × 0.42 λ0 at 4 GHz). The tested outcomes have a bandwidth of S11 ≤ -10 dB (81.25%) (5.2 GHz, 3.8-9 GHz) and a 3 dB axial ratio (AR) bandwidth (30.7%) (1.63 GHz, 4.48-6.11 GHz). The antenna's different parameters are discussed, which recommend the suggested antenna to be used in UWB, sub 6 GHz, and WLAN wireless applications.
ABSTRACT
A novel approach is proposed to design a circularly polarized (CP) hemispherical dielectric resonator antenna (DRA) with a wide axial ratio (AR) bandwidth by incorporating an additional dielectric substrate between the antenna and the ground plane. This is in addition to the lower feeding substrate that is located between the ground plane on one side and the feeding microstrip line on the other side. Adding another substrate on top of the ground plane provided an additional degree of freedom in the design that facilitated the achievement of ab 18% AR bandwidth. In addition, an integrated hemispherical DRA and perforated substrate configuration was utilized to achieve optimum effective substrate permittivity and overcome the DRA alignment and assembly challenges while maintaining the achieved wide CP bandwidth. A close agreement was achieved between measurements and simulations.
ABSTRACT
A compact multiple-input-multiple-output (MIMO) dielectric resonator antenna (DRA) that is suitable for internet of things (IoT) sensor networks is proposed with reduced coupling between elements. Two rectangular-shaped DRAs have been placed on the opposite sides of a Rogers substrate and each is fed using a coplanar waveguide (CPW) feed with slots etched in a dedicated metal ground plane that is located under the DRA. Moreover, locating the elements at the opposite sides of the substrate has improved the isolation by 27 dB without the need to incorporate additional complex structures, which has reduced the overall antenna size. Furthermore, a dual band operation is achieved since each antenna resonates at two frequencies: 28 GHz and 38 GHz with respective impedance matching bandwidths of 18% and 13%. As a result, the corresponding data rates are also increased independently. In addition to the advantages of improved isolation, compact size and dual band operation, the proposed configuration offers a diversity gain (DG), envelope correlation coefficient (ECC) and channel capacity loss (CCL) of 9.98 dB, 0.007, 0.06 bits/s/Hz over the desired bands, respectively. A prototype has been built with good agreement between simulated and measured results.
