Fractal loaded planar super wide band four element MIMO antenna for THz applications

2021 ◽  
pp. 100374
Author(s):  
Swarup Das ◽  
Debasis Mitra ◽  
Sekhar Ranjan Bhadra Chaudhuri
2006 ◽  
Vol 969 ◽  
Author(s):  
Krishna C. Mandal ◽  
Sung H. Kang ◽  
Michael K. Choi

AbstractThe single crystal growth of layered semiconductors GaSe and GaTe by vertical Bridgman technique using zone refined selenium (Se), tellurium (Te) and high purity (HP) gallium (Ga) have been described. The grown crystals (2.5 cm diameter and ∼10 cm long) have demonstrated efficient broadband tunable THz emission and as sensitive THz detectors. The crystals have shown promising characteristics with good optical quality, high dark resistivity, wide band gap (GaSe-2.01 eV and GaTe-1.66 eV at 300 K), good anisotropic (parallel, p & perpendicular, pa) electrical properties (σ∥ vs σ⊥ and μ∥ vs σ⊥) and long term stability. Different steps involved in processing GaSe and GaTe crystals as THz sources and sensors are described.


2017 ◽  
Vol 9 (8) ◽  
pp. 1741-1748 ◽  
Author(s):  
Mahdi Jalali ◽  
Mohammad Naser-Moghadasi ◽  
Ramezan Ali Sadeghzadeh

Wide-band circularly polarized multi-input multi-output (MIMO) antenna array with a 2 × 4 feed network was proposed for C-band application. Different unique techniques were utilized in the proposed array to enhance the antenna characteristics, such as gain, 3 dB axial ratio bandwidth (ARBW), impedance tuning, and ruinous mutual coupling effects. A miniaturized dual-feed Tai chi-shaped antenna element with a pair of feeding points and a pair of eyebrow-shaped strips was presented for enhancing circular polarization (CP) purity and impedance matching. For a better improvement of CP features, a 2*4 MIMO sequentially rotated (MIMO-SR) feed network was used to achieve broader 3 dB ARBW. Besides, the MIMO feature of the feed network could control the left- and right-handed CP, respectively. Ultimately, specific forms of slot and slit structures were applied onto the top layer of MIMO feed network that provided a high isolation between the radiating elements and array network. Furthermore, the diversity gain (DG) was studied. The extracted measured results illustrated an impedance bandwidth of 3.5–8.2 GHz at port 1 and 3.5–8.3 GHz at port 2 for VWSR < 2 and 3 dB ARBW of 4.6–7.6 GHz at port 1 and 4.6–7.5 GHz at port 2. The peak gain of 9.9 dBi was at 6 GHz.


In this article, we have presented various techniques that are used for improving different parameters related to UWB antenna. In this Paper, we planned for MIMO antennas in contemporary wireless communication which enhances the bandwidth and gives compact antennas. The antenna band we notched is of planned MIMO which offers an bandwidth with the operational band-notched. The bandwidth capacity of the antenna is from 2.93-20 gigahertz with sharp rejection at WLAN-band with isolation of not exactly - 22 dB is accomplished for the whole band, by utilizing a simple modified shaped structure in the bottom plane, port isolation and transmission capacity are improved. The diversity execution performance is likewise contemplated and whole outcomes shows it’s a potential point of using MIMO based diversity antenna for ultra wide band applications which is demonstrate in this paper. The parameters to assess the performance of the MIMO are explained, the whole examination completed in different sections has been outlined


Author(s):  
Mekala Harinath Reddy ◽  
D. Seela

This paper demonstrates a compact MIMO (Multi Input Multi Output) fractal type antenna for ultra-wide band applications. The proposed antenna is manufactured on a lowcost substrate material and the design is analyzed for various iterations in terms of reflection coefficient, gain, and bandwidth. The 50 Ω transmission line feed is used for both fractal patches and a metamaterial structure is used as the ground plane. The proposed design achieved a wide-band frequency response between 5.8 and 15 GHz, with the reflection coefficient of less than –10 dB. Reduced mutual coupling, positive gain and stable radiation patterns were observed throughout the operating band as well. The bandwidth of 9.2 GHz is achieved with the use of a metamaterial structure on the ground plane. The ECC and diversity gain obtained prove the excellent diversity performance of the antenna. The design was simulated using HFSS software and was tested in a lab.


A MIMO antenna with micro strip fed ultra wide band nature with characteristics of single band notching is presented in this paper. MIMO antenna has two monopole antennas. Larger impedance bandwidth is obtained by providing slots beside the feed line on ground plane. By using parasitic element on back side of patch band notching characteristics cab be obtained. Here, antenna size is 44x22x1.6 mm3 . This antenna operates over the frequency band 4GHz to 11GHz with notched frequency band 5.1GHz to 5.9GHz. By keeping two monopole antennas perpendicular to each other, isolation of less than - 15dB is obtained and good value of ECC is obtained.


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