“…A central metallic reflector has been placed in the center of two groups of four‐elements of dielectric resonator antennas (DRAs) (Sharawi et al., 2017), as represented in Figure 16b for isolation and tilting the radiation pattern of one group resonating at 5.8 GHz by 45° as compared to another group resonating at 2.45 GHz. Similarly, a simple metallic strip (Roshna et al., 2015), T‐shaped parasitic strip (Kang et al., 2015), a modified interdigital capacitor (Kumar et al., 2018b), a novel ITI‐shaped parasitic structure (Kumar et al., 2019a), parasitic inverted L‐element with an open stub (Lee et al., 2012), H‐shaped strip (Li et al., 2016), floating parasitic decoupling structure (Khan et al., 2014), a rotated “+” shaped rectangular strip pair (Singhal, 2019) as represented in Figure 17a, a rectangular parasitic element is embedded at the substrate backside (Hatami et al., 2019), two separate rectangular shapes and T‐shaped parasitic elements (Faraz et al., 2019), as represented in Figure 17b, cross‐shaped metallic fence (Caizzone, 2017), stepped cross‐shaped reflector strip (Thummaluru et al., 2019), a circular parasitic element at the backside of the radiating patch (Ghimire et al., 2019), a novel reversed S‐shaped walls (Wang et al., 2019), a decoupling metal strip loaded with an inductor (Nie et al., 2019), an optimized parasitic element (Addaci et al., 2012) as represented in Figure 18a, slotted meander‐line resonator (SMLR) (Alsath et al., 2013) as represented in Figure 18b, a simple rectangular parasitic structure at the back (Azarm et al., 2019), diagonal parasitic strip at the back (Chouhan et al., 2019), Minkowski fractal‐shaped isolators (Debnath et al., 2018) as represented in Figure 19a, a complementary pattern (CP) comprised of meandered transmission lines (Hwang et al., 2010), a group of six parasitic elements (Min et al., 2005), as represented in Figure 19b, two parallel strips, or a single strip embedded with patterned meander‐shaped slot (Isaac et al., 2018) as represented in Figures 20a and 20b, two parasitic monopole providing a decoupling path (Li et al., 2012) as represented in Figure 21a, a novel H‐shape parasitic element embedded in the ground plane (Liu et al., 2018) as represented in Figure 21b, a T‐shaped coupling eleme...…”