The Research Of Compact Ultra Wideband MIMO Antennas

In recent years,wireless portable mobile communication devices has been developed rapidly and used widely.Meanwhile,the antenna of the small mobile terminal,as a critical component taking responsibility for the transmission and reception of signals in the moblie terminal,has made great progress with the technological advance.Gradually,it becomes more broadband,possessing more antennas and more miniatured.The trend of the broadband promotes the development of the Ultrawideband(UWB)antenna in more than a decade.The UWB antenna features covering wider frequency band,possessing larger channel capacity and higher transmission rate,and can achieve short-range peer-to-peer wireless communications effectively.Paradoxically,due to crowded frequency spectrum,the broadband easily leads to the interference of different frequencies of different communications protocols.However,the UWB antenna with notched band has solved this problem.The trend of the multi-antenna(ie,Multiple-Input Multiple-Output(MIMO)technology),can further increase the channel capacity.Combined with the UWB antenna to form the UWB MIMO antenna,it can combat multipath fading in the scattering environment.The miniatured antenna can allow for adequate spaces for the other circuit components.In this paper,basing on the compact UWB MIMO antenna,we design two antennas with the notched band and two without,as follows:1.Compact Bluetooth/UWB MIMO antenna using the common monopole patch as the main radiator.A C-shaped branch protruded from the corner-truncated rectangular monopole radiating patch,is used for compatibility with the frequency band of Bluetooth.Two rounded corners on the ground improve the impedance bandwidth at medium-high frequency.The protruded ground stub decouples effectively.This work has been published on-line in the journal Microwave and Optical Technology Letters indexed by SCI and the international conference The 2016 IEEE International Conference on Computational Electromagnetics(ICCEM)indexed by EI.2.Compact UWB MIMO antenna with three notched bands.It consists of two rectangular printed monopole elements and a common ground plane forming a dual-antenna structure.For three different rejected bands of the wireless local area network(WLAN)covering 5.15–5.35 and 5.725–5.825 GHz and 4 GHz C-band(3.7-4.2 GHz)of satellite communication systems,three different resonators were designed to form three independently adjustable rejection bands.In addition,A simple stepped ground stub protruded in the middle ground improves the isolation of the MIMO antenna dramatically.The simulated and measured results agree well.This work has been published on-line in the journal Progress In Electromagnetics Research Letters indexed by EI.3.Compact UWB MIMO antenna with high frequency selectivity and bandwidth-controllable notched band.On the basis of the above work,for achieving a rejected band with high frequency selectivity at the IEEE 802.11 WLAN band from 5.15 GHz to 5.85 GHz centered at 5.5 GHz,two band-notch structures in different locations beside the radiating patch,are utilized.Finally,the bandwidth of the notched band can be easily adjusted individually.Meanwhile,the decoupling effect is good and the measured results agree well with the simulated results.This work has been published on-line in the journal Microwave and Optical Technology Letters indexed by SCI and the international conference The 37 th Progress In Electromagnetics Research Symposium indexed by EI.4.Compact UWB-MIMO antenna using the ground linearly tapered slot as the main radiator.It is two ground linearly tapered slot coupled with the feedlines to radiate that reduce the dimensions.The rectangular slot in the bottom of the feed line improves the impedance bandwidth.In addition,the three-level slot improves the isolation of the MIMO antenna.The simulated and measured results agree well.This work has been published on-line in the journal Progress In Electromagnetics Research C indexed by EI.