The wireless technologies working in 6G and beyond will fully connect this world. We need intelligent devices. Due to limitations in 5G MIMO, we need to expand our devices to 6G in order to meet the industrial automation. The fourth-generation (4G) and fifth-generation (5G) cellular systems increased the data rate as well as system capacity. As conventional antennas fail to meet the multitasking from a single device (multiple antenna wireless services), the multiband is a preferable device which can work on different frequency bands. The grooved structures are also used to make applications for 4G-LTE, WLAN, Bluetooth, WiMAX and other wireless services. At present, 6GHz band is partly used for Space Research, which supports internet speeds up to 10Gbps similar to 5G speed, 100 times faster than 4G. 3.1 to 10.6GHz is used for ultrawideband. It is used in multiband orthogonal frequency division multiplexing (MB-OFDM). Here different designs are proposed with two-element antenna and with grooved structures that have smaller dimensions with high gain and maximum radiation efficiency.
Two element/four-element Multiple input multiple output (MIMO) antennas with the substrate FR4 and Rogers RO4350B have been designed. These are working in dual bands/ multiple bands for 4G/5G applications. New efficient and accurate analytic models of ultra-wideband (UWB) microstrip antennas are also introduced to design small printed parabolic shape monopoles with single and dual band notch antennas shaped with rectangular cavities and corrugated edges for wireless applications. These microstrip antennas along with single and dual band-notch in UWB systems are also compact with multifunctional features reducing the number of antennae in wireless devices. Also useful in wireless networks having a wide radiation pattern and in biomedical diagnosis. These antennas are lightweight, and robust and also give low cost of production. Ultra-wideband (UWB) wireless technology is preferable for short-range, very high data rate wireless applications, UWB Radars and highly secured networks. It has high performance in adverse weather and lightning conditions giving good precision with low output power requirement. UWB technology gives good noise immunity and it can be used to penetrate the materials easily. UWB communication works at very low energy levels in case of short-range and gives high bandwidth. In these designs, we have achieved a reduction in the size of the antenna as compared with the earlier designs.
