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.
