In this palimpsest, an uncomplicated design technique of dual-polarized antenna array is suggested for the fifth-generation (5G) mobile terminal. Its structure contains a pair of conventional slot antenna arrays arranged with a 90° difference on the top portion of the smartphone printed circuit board (PCB). The employed substrate is Rogers 5880 laminate with an overall size of 75×150×1.2 mm 3. The proposed design is designed to work at 28 GHz. The essential characteristics of the design in terms of S-parameters, radiation patterns, efficiency, and antenna gain are investigated. The obtained results show good features of the antenna array for non-identical polarizations.

In this study, a new design of dual-polarized ultra-wideband (UWB) antenna is proposed. The antenna design contains a circularring slot radiator fed by two independently semi-arc-shaped microstrip feeding lines which can exhibit polarization diversity characteristic. A low-cost FR-4 dielectric (ε= 4.4, δ= 0.02) is used as the substrate. The characteristics of the dual-polarized UWB antenna are examined using both simulations and measurements and good results are achieved. An impedance bandwidth (S11 ≤ -10 dB) of 2.5-10.2 GHz with 121% fractional bandwidth (FBW) is achieved for the design. However, for S11 ≤ -6 dB, this value is more than 130% (2.2-11 GHz). The proposed UWB antenna offers good isolation, dual-polarized function, and sufficient efficiency which make it suitable for different applications such as radar and microwave imaging.

In this paper, a high efficiency phased array antenna is introduced for fifthgeneration (5G) smartphones. The configuration of the design is achieved by employing eight insensitive L-ring/slot-loop resonatorss with linear array form on the top of the handset mainboard. The design exhibits high radiation performances even though the beam-steerable array is implemented on a lossy FR-4 material. The proposed design exhibit a frequency bandwidth of 18-20 GHz with a single resonance at 19 GHz. The designed antenna exhibits wide beam-steering, high efficiencies, and sufficient gain levels at 19 GHz of 5G communications. In addition, the proposed phased array design has sufficient radiation behavior in the adjacency of user-hand phantom. Moreover, its characteristics are insensitive for various substrate types.

A compact coplanar waveguide (CPW)-fed antenna with improved bandwidth and a band-stop property is represented for ultra-wideband (UWB) communications. Its configuration is composed of a modified circular-ring radiation patch with a cross-strip and a pair of protruded arms and a semi-circular ground plane. It is designed on a lowprofile FR-4 substrate with δ= 0.02, ε= 4.4, and h=1.6 mm. By modifying the ground plane and also adding a cross-strip into the circular-ring radiation patch, the impedance bandwidth of the antenna for S11≤-10 can be improved significantly. The band-notched characteristic of the design is achieved by using the pair of protruded arms. The proposed antenna exhibits a wide usable fractional bandwidth from 3.1 to 24 GHz and a frequency notch-band in 5.5 GHz of WLAN systems. The performance of a 4×4 MIMO configuration for the UWB antenna is also studied and good results are achieved.

In this paper, a new high-gain differential-fed dual-polarized microstrip filtering antenna with high common-mode rejection is presented. Two differential pairs of probe feeding ports are utilized to provide differentially exciting signals. The filtering response is achieved by introducing four symmetrical open-loop ring resonator slots on the top layer surrounding the four excitation ports of the patch antenna. The resonators can produce nulls at the low edge of the passband bandwidth with high gain and wide stopband characteristics. Because of the strictly symmetric configuration of the proposed antenna, the design is studied and analyzed only in one polarization configuration. Compared with other presented filtering antenna designs, the proposed design has not only high gain and dual-polarized characteristics but also introduces high efficiency and much lower crosspolarization level due to the differentially driven ports. The filtering antenna is designed, simulated and optimized using computer simulation technology (CST) software using a Rogers TMM3 substrate with a relative dielectric constant of 3.45. Also, the antenna has a single layer substrate with a height of 0.035 of the free space wavelength and operating at 3.54 GHz for 5G communications."