A Novel dual notched 4-element MIMO (Multi-Input-Multi-Output) antenna with gap sleeves and H-slot is proposed and fabricated for UWB (ultra wide-band) applications. The proposed antenna is CPW (Co-Planar Waveguide) fed and consists of four orthogonal elements with good isolation. It has low profile and small dimensions of 80x80x1.6mm3. The proposed MIMO antenna achieved an impedance bandwidth (S11<-10dB) from 2.1GHz - 20GHz with notches from 3.3GHz - 4.1GHz and 8.2GHz - 8.6GHz frequency bands. These achieved notches can filter the interference of WiMAX(3.3GHz - 3.7GHz), and military/radar applications band (8.2GHz - 8.6GHz). Mutual coupling among the elements is also below -25dB. The performance parameters of proposed MIMO antenna are relatively good with very low ECC (Envelop Correlation Coefficient) less than 0.02 except at notches and DG (Diversity Gain) nearly 10. Peak gain of 5.8dB is achieved by the proposed antenna and the radiation efficiency is also above 80% except at notches.The computer-generated and experimental results are in accord and therefore, the proposed four element MIMO antenna can be suggested as a suitable aspirant for UWB applications with stop bands for WiMAX and military/radar applications.

A novel octahedron frequency reconfigurable multiband antenna for microwave sensing-based IoT applications is proposed in this work. This reconfigurable antenna operates over the bands 1.57–2.15 GHz, 2.13–3.0 GHz, 3.17–3.43 GHz, 5.2–5.8 GHz, 6.3–6.78 GHz, 8.31–8.90 GHz, 9.04–9.58 GHz and 12.03–13.14 GHz which can be used for wireless sensing, space and IoT applications. By using omega shape slot in the radiating structure and with PIN diodes switching to change the current direction, the desired resonant frequencies are achieved. The PIN diodes are controlled by using an IoT device NodeMcu. As per the software programmed, the NodeMcu switches the PIN diodes into ON and OFF conditions. We can change the program and monitor through the World Wide Web. The s-parameter characteristics and the radiation patterns have been measured, and good compatibility between simulated and measured results has been identified. The designed model is tested with CDAC Cmote device and controlled through IoT for data transmission and reception at desired operating bands.

In this paper, a dual notch Ultra Wideband (UWB) monopole antenna with compact dimensions of 37.8 × 27.1 × 1.6 mm 3 is presented. Octagon patch with a defected ground structure is used to attain the wide frequency range of 3.17 GHz-11.61 GHz with ultra-wide impedance bandwidth of 8.33 GHz. The band notch characteristics in WiMAX (3.2 GHz-3.67 GHz) and WLAN (4.32 GHz-5.81 GHz) bands are achieved using inverted pi-slot in the radiating element and a pair of double split ring resonators (DSRRs) on either sides of the feed, respectively. Reconfigurability in the bands is obtained by using BAR64-03W pin diodes switching at the appropriate placement in the antenna structure. The proposed antenna exhibits efficiency of 88% in operating and 20% in nonoperating frequencies. The proposed antenna is designed, simulated, and optimized using HFSS 19 electromagnetic tool. The measured results are tested using combinational analyzer in a chamber with antenna measurement setup for validation and found in good matching with simulation.