A novel foot-shaped elliptically embedded patch-ultra wide band antenna with quadruple band notch characteristics verified by characteristic mode analysis

A novel foot-shaped elliptically embedded patch (EEP) ultra wide band (UWB) antenna with four band elimination features is demonstrated. The designed antenna incorporates embedded ellipses as its structure, a 50 omega microstrip line feed, and a defective rectangular ground structure (DRGS). The antenna has 22 x 32 mm(2) in size, with a frequency spectrum of 2.8-13.3 GHz, and a fractional bandwidth (FBW) of 130%. On the radiating element, four half-wavelength inverted U-shaped slots are used to create four band-stop characteristics and are verified by using characteristic mode analysis (CMA). The antenna has four band rejection characteristics, exhibiting S-11 > -10 dB at 3.37 GHz for Worldwide Interoperability for Microwave Access (WiMAX) (3.17-3.61 GHz), 3.95 GHz for C (3.70-4.34 GHz), 5.49 GHz for wireless local area network (WLAN) (5.16-5.82 GHz), and 8.31 GHz for ITU-8 (8.10-8.64 GHz) bands. The proposed EEP radiator with four notch characteristics has voltage standing wave ratio (VSWR) values of 10.5, 25.6, 8.9, and 3.8 for notch center frequencies of 3.37, 3.95, 5.49, and 8.31 GHz. The proposed antenna peak gain fluctuates from 1.6 to 4.4, peak efficiency is 98.92%, group delay variations are less than 0.65 ns, linear phase response, and transfer function is less than -35 dB all across the entire UWB operating bandwidth except for notched frequency bands, which makes it appropriate for UWB portable applications.