This research proposes a dual-frequency circularly polarized truncated square aperture patch antenna with slant stripline and L-shaped slot for WLAN applications. In the antenna design, the parameters were optimized and the WLANenabled dual-frequency (2.4 and 5.8 GHz) antenna was realized. Simulations were subsequently carried out for the impedance bandwidth ( S 11 ) < −10 dB, axial ratio (AR) ≤ 3 dB, optimal gain, and bidirectional radiation pattern. To validate, an antenna prototype was fabricated and the experiments were undertaken. The simulated and experimental results are in good agreement. In essence, the proposed WLAN-enabled dual-frequency circularly polarized antenna is most suited for applications in the vertically and horizontally elongated areas, including in the tunnel, train carriage, and buildings.

The capacitively coupled microstrip antenna for 4G and Wi-Fi applications is presented. The antenna has a compact size which can easily be installed into many types of wireless communication device. The antenna is designed on FR4 substrate with a total dimension of 70 mm × 9 mm × 0.8 mm. The structure of the antenna consists of two main parts. The T-shape feeding patch located between two radiating strips with the ground strip being placed behind them. The surface current distribution and parametric study was analyzed to determine the suitable parameters. Furthermore, the antenna prototype was fabricated and tested. The operating frequency range of the proposed antenna is between 1.7 GHz and 2.5 GHz for the |S 11 | of less than -10 dB. The antenna provides a linear polarization in a single beam direction covering approximately one quadrant of the free space with a maximum gain of higher than 1.47 dBi on the entire frequency band.