Compact ultra-wideband slot antenna with three notched-band characteristics

A very compact ultra-wideband (UWB) slot antenna with three L-shaped slots for notched-band characteristics is presented in this article. The antenna is designed and fabricated using a new stepped slot with different size, integrated in the ground plane, and excited by a 50 omega microstrip transmission line. The stepped slot is used to minimize the dimensions of the antenna and to achieve an impedance bandwidth between 2.65 and 11.05 GHz with voltage standing wave ratio (VSWR) less than 2. The length of the stepped slot is equal to a quarter wavelength to create a resonance in the desired frequency. Three L-shaped slots with various sizes are etched in the ground plane to reject three frequency bands in C-band (3.7-4.2 GHz), WLAN (5.15-5.825 GHz), and X-band (7.25-7.75 GHz), respectively. The notched-band frequency can be controlled by changing the length of the L-shaped slot. The proposed antenna has a very small size (20.25 x 8 x 1.27 mm(3)) compared with previous works. The measured and simulated results show a good agreement in terms of radiation pattern and impedance matching.