## 1 Introduction  
Recently, mobile communication networks were developed rapidly to satisfy the current mobile communication services [1]. However, the evolution of current mobile communication systems requires high data rates in the range of Giga bits per second [2]. Thus, the need to develop modern antenna designs to serve the current wireless communication systems became one of the most urgent essentials [3]. In such cases, enormous challenges face scientific researchers to develop antennas with a wideband and enhanced gain due to the antenna size limitations [4]. However, many researchers succeeded to overcome the motioned challenges by invoking several techniques. For example, the authors in [5] designed a composite right-left-hand microstrip antenna with an enhanced gain-bandwidth product for RF energy harvesting [6] at 2.45 GHz and 5.8 GHz. A low-profile fractal antenna structure based on MTM array was developed for modern Wi-Fi systems [7]. In [8], a circularly polarized fractal patch of Koch-snowflake 1 st iteration with ground plane MTM defects was proposed for 5G handsets at 3.5 GHz only [9].  
In another aspect, MTM played a major role in developing the antenna systems due to the unusual properties based on exceptional electromagnetic constitutive parameters [10]. Therefore, the authors in [11] used certain MTM inclusions on their antenna patch to control the beam-steering capacity by using two semiconductor switches. Another design was proposed in [12] based on using an MTM layer on the top of an antenna patch to enhance the antenna gain at Wi-Fi bands. The introduction of the MTM structure to the antenna ground plane was developed in [13] to minimize the back lobe effects at 3.4 GHz. Another MTM introduction was proposed in [14] to ensure the antenna surface wave propagation toward the end-fire direction for gain-bandwidth enhancements. Finally, a design of MTM antenna was proposed in [15] to realize a gain enhancement at 4.6 GHz only for 5G communication networks.  
In [16], a microstrip antenna array was presented for 5G networks at 28 GHz bands-based 4 \(\times\) 4 elements; however, the selected band was suffering from a limited propagation that was not considered in their work. Another design was proposed in [17] based on using a triple-band with dual polarization printed circuit antenna array for MIMO systems in the sub-6 GHz for 5G applications. An antenna array was developed for 5G systems by orienting four antenna elements on a 3D profile and separated with MTM defects; such an antenna provided a high gain-bandwidth product. However, the proposed antenna in [18] was very complicated and not applicable with low-profile devices [19]. Moreover, another design was proposed in [20] based on a reconfigurable antenna element with optical switches but without considering the array systems analysis. In [21], a design of a microstrip antenna based on MTM defects was proposed for the same application with a limited gain at a single frequency band.  
In this work, an antenna design based on a novel MTM array is proposed to realize a miniaturized antenna structure for 5G communication networks. The proposed MTM arrays are mounted in parallel to a conductive trace to ensure in-phase reflection characteristics and high-impedance response against the effects of the surface wave retardation from the antenna edges. Such technique could realize gain-bandwidth enhancements over the conventional printed antenna structures as will be proven later. In Section 2, the antenna geometrical details are presented. The antenna design methodology is discussed in Section 3. In Section 4, the obtained results are validated. Finally, the paper is concluded in Section 5.