“…For example, an inverted L-shaped slot is included in the ground plane [2], while U-shaped [3], W-shaped [4], hat-shaped [5], and cup-shaped [6] slots are incorporated in the radiating patch. Antennas with dual- [7–9], triple- [10, 11], and quad- [12, 13] notched characteristics by using different combinations of various slots have also been reported. Although incorporation of slot structures is a simple and popular approach, other options such as introducing parasitic strips above the ground plane [14], use of split-ring resonators [15], and Hilbert curves [16] are also found to be very effective at notch out the desired frequency band.…”