Small Antenna Design of Triple Band for WIFI 6E and WLAN Applications in the Narrow Border Laptop Computer

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Introduction
High-speed data rates are the most effective solution with wireless local area network (WLAN) called authorize user wireless mobility. However, with the current technology of wireless systems, high-speed downloads are limited in applications such as the Internet of things and 4K and 8K video. e end users of such products consider the upload and download speeds of WLANs to be unsatisfactory. erefore, the Wi-fi 6E (the sixth generation of Wi-fi) standard will be introduced in 2021. e bandwidth of Wi-fi 6E is between 5.925 and 7.125 GHz, with 14 × 80 or 7 × 160 MHz channels. Wi-fi functionality is essential for most wireless laptop features. erefore, laptops should be outfitted with Wi-fi 6E. In the current market, the screen-tobody ratio provides useful information to the consumer. However, the spacing of the border area is limited because less than 4 mm is reserved for antennas. Studies [1][2][3][4] have discovered that the guidelines for designing WLAN antennas with coplanar waveguide, slot, and bend-type architectures cannot be implemented because of limited dimensions. In [5], small dimensions and a meandering shape with loop-type antennas were used. Other studies have investigated designs such as PIFA or monopole antennas for Wi-fi applications [6][7][8][9]. In [10][11][12], the authors used chip element to achieve small size and narrow boarder antenna design. However, the used of the inductor makes the hardware complex and also increases the difficulty of the manufacturing process. is study designed an antenna to perform in low-frequency (2.4-2.484 GHz) to high-frequency (5.925-7.125 GHz) bands by using a direct-fed arm and a couple-fed arm to enable full functionality in WLAN and Wi-fi 6E applications.

Experimental Results and Parametric Study
Simulations were conducted using Ansys HFSS software to obtain the S 11 values used in this study. As shown in Figure 4, the measurements indicated good performance. e S 11 value was −10 dB for covering the WLAN and Wi-fi 6E systems. Figure 5(a) presents the length of the couple-fed right arm and the various simulated S 11 values. When the length of the couple-fed right arm was decreased by 1.5 and 3.0 mm, the 2.45 GHz fundamental mode shifted to a higher frequency, and the 2.4 GHz higher 3λ/4 mode at 5.825 GHz and 5λ/4 mode at 6.85 GHz also shifted to higher frequencies, resulting in a mismatch. Figures 5(b)-5(d) display the current distribution of the couple-fed right arm at 2.45, 5.825, and 5.85 GHz. For the resonant mode at 2.45 GHz, one null on the couple-fed right arm was observed, as shown in Figure 5(b). erefore, the 2.45 GHz mode was in the λ/4 fundamental mode. For the resonant mode at 5.825 GHz, two nulls on the couple-fed right arm were observed, as shown in Figure 5(c). erefore, the frequency is 5.825 GHz in the 2.45 GHz higher 3λ/4 mode. For the resonant mode with 6.85 GHz, three nulls were observed on the couple-fed right arm, as shown in Figure 5(d). erefore, the frequency is 6.18 GHz in the 2.45 GHz higher 5λ/4 mode. e simulated S 11 values in Figure 6 indicate the different lengths of the couple-fed left arm. When the arm was        Figure 7(b) presents a simulation of the directfed left arm and current distribution at 5.16 GHz. One null was observed in the arm. us, the 5.16 GHz fundamental mode was λ/4. Observed direct-fed left-side arm had one null. us, the 5.15 GHz fundamental mode was 1/4 λ. e simulated S 11 values presented in Figure 8 were derived from the different lengths of the direct-fed right arm.
is can influence high band matching. When the length of the arm was reduced by 1 and 2 mm, mismatches occurred at 5.16, 5.825, and 6.85 GHz. Figure 9 presents the simulated and measured of antenna radiation patterns in the x-y, x-z, and y-z planes at 2.45, 5.16, 5.825, and 6.85 GHz. In the x-y plane at 2.45 and 5.16 GHz, the radiation pattern was nearly omnidirectional. erefore, 2.45 and 5.16 GHz are the fundamental λ/4 modes. Figure 10 presents the measured gain and efficiency of the antenna at 2400-2484 and 5150-7125 MHz. e antenna gain was 1.24-2.14 dBi (0.9-dBi variation), and the efficiency was 62.7%-68.9% (6.2% variation) at 2400-2484 MHz. e gain was above 1.13 dBi, and the efficiency was 53.4%-63.1% (9.7% variation) at 5150-5850 MHz. e gain was above 0.8 dBi, and the efficiency was 55.4%-68.6% (13.2% variation) at 5925-7125 MHz. Table 3 presents the measured gain, efficiency, resonant frequency, and bandwidth. As discussed, the antenna exhibited stable gain, high efficiency, and favorable radiation pattern.  To compare the performance of the antenna with that of other antennas, Table 4 presents the dimensions, w/wo chip element, support bandwidth, and dimension comparison. In [6][7][8], the PIFA structure was used to achieve small size antenna design. However, W parameter is larger than proposed antenna not suitable for current narrow-border products. In addition, antenna support bandwidth is less than proposed antenna. In [10][11][12], the authors used chip International Journal of Antennas and Propagation element to achieve small size and narrow boarder antenna design. However, the use of inductor makes the hardware complex and also increases the difficulty of the manufacturing process. In [9], the antenna dimensions were larger than proposed antenna and support bandwidth was less than proposal antenna. Our proposed antenna dimension compared with reference is not the smallest, but the parameter of W, support bandwidth, and easily manufacturing process are suitable for current narrowborder products.

Conclusions
is study developed a small (43 × 3 mm 2 ) planar antenna for narrow-border notebook computers. e antenna covers the frequency ranges of 2.4-2.484 and 5.15-7.125 GHz by using two fundamental modes and two higher modes. e antenna support range includes those of the WLAN and Wi-fi 6E systems. e antenna is small, supports wide bands, has an omnidirectional radiation pattern at 2.45 and 5.16 GHz, and exhibits stable gain and high efficiency. According to the results, the antenna is suitable for narrow-border laptops.

Data Availability
e data used to support the findings of the study are available from corresponding author upon request.

Conflicts of Interest
e authors declare that they have no conflicts of interest.