###### Abstract
A unique structure proposed by combining a rectangular monopole and parasitic patch elements results in a small, three-notch band monopole antenna [14]. A 50 ohm impedance feed line is perfectly matched with a corner twisted-type rectangular radiating structure on the upper side and to the defective ground surface. The designed antenna has triple broad notch band characteristics between the WLAN band at 4-6 GHz, the satellite communication band at 7.6-9.8 GHz, and the 10.5-11.5 GHz band [15]. A unique heart symbol-shaped electrically compact antenna attached to a planar AMC--artificial magnetic conductor on an FSS-frequency selection surface for use in WLAN (i.e., 5.8 GHz) and WiMAX (i.e., 3.5 GHz) applications is designed in [16]. The overall dimension of 0.63 \(\lambda\)0 \(\times\) 0.63 \(\lambda\)0 \(\times\) 0.33 \(\lambda\)0 is surrounded by a heart structure-shaped closed resonator ring (HCRR-HIGH-CAPACITY RADIO RELAY) as a shunt inductor. The designed model is supported by a model artificial magnetic conductor (AMC), and a distinct reflection of \(-\)900 to +900 has been seen in the AMC structure's reflection phase [17]. A triple-band notching property ultra-wideband antenna is designed with a CSRR--complementary splitresonator and a patch with an inverted T-structure stub [18]. In the UWB--Ultra-wide band, it emits a constant dipole pattern like radiation in the E-plane and an omnidirectional pattern observed in the H-plane. Combining a DGP--defective ground plane, inverted T-structure stub, and CSRR generates triple-notch bands with characteristic frequencies at 4.4 GHz (for RFID--Radio-Frequency Identification applications), 6.8 GHz, i.e., RFID, and 9.2 GHz, i.e., radar system application purposes, respectively. A highly effective multi-broadband resonance tree-shaped fractal antenna is proposed in [19]. The partial portion etched ground structure is altered by inserting a narrow slotted rectangular-shaped slot, and the recommended circular-shaped patch element is modelled by incorporating slots in similar to a tree-shaped fractal antenna structure. The developed antenna is made from an FR4 dielectric substrate of dimensions 40 \(\times\) 25.05 \(\times\) 1.6 mm\({}^{3}\). The designed antenna operates in four different bands with 10 dB impedance bandwidths of 600 MHz (2.2 to 2.8 GHz), 1070 MHz (3.3 to 4.37) GHz, 2550 MHz (4.75 to 7.3 GHz), and 2200 MHz (9.7 to 11.9) GHz, according to the measurement results. A hexa-band antenna with a special structure for LTE, Bluetooth, and Wi-Max devices is proposed in [20]. Four PIN diode switch-based frequency-configurable dual operating band antennas were designed for LTE 2500 band and WiMAX applications. The fabricated/prototyped antenna works in the relevant LTE band and WiMAX frequency bands (2.5-2.69 GHz and 3.4-3.6 GHz). The designed antenna emits both unidirectional and bidirectional radiation at higher frequency bands [21]. A non-symmetric electromagnetic structured band gap antenna (EBG--Electronic Bank Guarantee) has been designed for wireless communication applications. By including an EBG structure in the antenna, the gain is increased from 2.8 dB reading to 13.9 dB, and a parametric analysis is carried out to optimise the antenna performance characteristics, with an efficiency higher than 82.5%.