Quasi-self-complementary antenna for multifunctional wireless applications

In this paper, a quasi-self-complementary antenna (QSCA) for multifunctional (i.e., wideband and dual-band wireless local area network (WLAN)) applications is presented. The proposed antenna consists of a pie-shaped radiating patch fed by a 50-Ω microstrip line and its complementary metal structure connected to the ground plane. With properly adjusting the angle (θ) of the pie-shaped notch and the pie-shaped stub on the ground plane, an alternative function of the antenna can be achieved. For θ = 0°, the antenna has a wide −10 dB impedance bandwidth of 4848 MHz (about 102% centered at 4.77 GHz). For θ = 25°, the wideband QSCA can be transformed to a progressive dual-band antenna and thus provides two separate impedance bandwidth of 292 MHz (about 11.9% centered at 2.45 GHz) and 1548 MHz (about 28.1% centered at 5.5 GHz). The measured results of the proposed antenna also exhibit respectable radiating patterns and gain values.