Highly compact size serpentine‐shaped multiple‐input–multiple‐output fractal antenna with CP diversity

2018 ◽  
Vol 12 (4) ◽  
pp. 636-640 ◽  
Author(s):  
Amer T. Abed
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Abubaker Ahmed Elobied ◽  
Xue-Xia Yang ◽  
Ningjie Xie ◽  
Steven Gao

This paper presents a close-spaced dual-band 2 × 2 multiple-input multiple-output (MIMO) antenna with high isolation based on half-mode substrate integrated waveguide (HMSIW). The dual-band operation of the antenna element is achieved by loading a rectangular patch outside the radiating aperture of an HMSIW cavity. The HMSIW cavity is excited by a coaxial probe, whereas the rectangular patch is energized through proximity coupling by the radiating aperture of HMSIW. The antenna elements can be closely placed using the rotation and orthogonal arrangement for a 2 × 2 array. Small neutralization lines at the center of the MIMO antenna can increase the isolation among its elements by around 10 dB in the lower band and 5 dB in the higher band. A prototype of the MIMO antenna is fabricated and its performance is measured. The measured results show that the resonant frequencies are centered at 4.43 and 5.39 GHz with bandwidths of 110 and 80 MHz and peak gains of 6 and 6.4 dBi, respectively. The minimum isolation in both bands is greater than 35 dB. The envelope correlation coefficient is lower than 0.005 within two operating bands.


2016 ◽  
Vol 9 (3) ◽  
pp. 573-580 ◽  
Author(s):  
Garima Srivastava ◽  
B. K. Kanuijia ◽  
Rajeev Paulus

A compact printed 2 × 2 ultrawideband (UWB) multiple input multiple output (MIMO) antenna with a single circular patch as a common radiator for both the antenna elements is presented in this paper. A single circular patch is excited by two tapered CPW feeds for dual polarization. To improve the isolation between two ports, a rectangular slot of dimension L1 × W1 is created in the radiator. The UWB MIMO antenna has impedance bandwidth of 3–12 GHz with a isolation better than 17 dB between the two ports. The envelope correlation coefficient and the capacity loss are evaluated to ensure the good diversity performance of UWB MIMO antenna. The antenna has a compact size of 45 × 45 mm2 and is fabricated on low cost FR4 substrate and measured using Agilent VNA. The simulated and measured results show that the proposed UWB antenna is good candidate for UWB MIMO applications.


2019 ◽  
Vol 16 (10) ◽  
pp. 4242-4248
Author(s):  
Manoj Kapil ◽  
Manish Sharma

In this research article, a compact MIMO (Multiple-Input-Multiple-Output) antenna with inclusion of two notched bands characteristics is presented. Designed MIMO antenna consist of dual radiating patches printed on one surface of the substrate which covers measured wide impedance bandwidth of 2.88 GHz–19.98 GHz and satisfies bandwidth ratio more than 10:1 for superwideband with compact size of 18 mm × 34 mm. Two radiating patch are placed symmetrically for MIMO configuration and notched bands to eliminate WiMAX/C and WLAN bands are obtained by attaching inverted T-shaped stub on radiating patch and etched inverted U-shape slit in microstrip feed. Isolation between the two radiating patch is maintained by adding two L-shaped stub in slotted rectangular ground plane. Measured radiation pattern are stable in operating band and offers maximum 4.23 dBi and 89% gain and radiation efficiency respectively. Moreover, antenna shows good diversity performance with Envelope-Correlation-Coefficient (ECC) < 0.5, Directive-Gain (DG) > 9.95 dB and Total-Active-Reflection Coefficient (TARC) < -30 dB.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Enze Zhang ◽  
Jinghui Qiu

A four-port dual-band dual circularly polarized (CP) stack-up patch antenna is introduced for multiple-input-multiple-output (MIMO) RFID application. The proposed antenna adopts two FR 4 substrates and one Rogers Ro4350b substrates. Two pairs of isolated ports work at FCC UHF/MW-RFID bands (0.902–0.928 and 2.4–2.485 GHz) with port isolations of 20 dB and 25 dB, respectively. Four inverted-F radiating elements fed with a 90° phase-delay feeding network realize the CP radiation at the FCC UHF-RFID band (0.902–0.928 GHz). The corner-truncated square slot and patch are implemented to obtain CP modes at the MW-RFID band. The relative impedance bandwidths in the FCC UHF and MW band are 10.9% and 9.4%, respectively, with peak gains of 4.1 and 7.2 dBic. The antenna’s MIMO performance of envelope correlation coefficient (ECC) is lower than 0.01, and diversity gain (DG) is close to 10 dB. Thanks to the stack-up configuration, the dual-band RFID antenna realizes good antenna performance with a compact size of 0.6 × 0.6 × 0.07 λ3.


Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 3031
Author(s):  
Jayshri Kulkarni ◽  
Abdullah G. Alharbi ◽  
Arpan Desai ◽  
Chow-Yen-Desmond Sim ◽  
Ajay Poddar

A single radiator that is a part of four-port diversity Multiple-Input Multiple-Output (MIMO) antenna design is composed of four octagonal rings embedded between the two opposite sides of a T-shaped conductive layer surrounded by inverted angular edge cut L-shaped and E-shaped structures. The radiators are placed at the four corners with common ground at the center of a smartphone to form a four-element mobile MIMO antenna. The printing of the antenna is carried out on the flexible polyamide substrate (dielectric constant = 3.5 and loss tangent = 0.0027) with dimensions of 70 × 145 × 0.2 mm3. A wide impedance bandwidth of (84.12%) 2.39 to 5.86 GHz is achieved for all four radiators. The compact size of the radiators along with their placement enables the proposed MIMO antenna to occupy much less area while preserving the space for 2G/3G/4G antennas. The placement of the antennas results in self-isolation between antenna elements by achieving isolation greater than 17.5 dB in the desired operating bands. Furthermore, besides showing a high efficiency of 85% and adequate gain above 4 dBi, good diversity performances such as Envelope Correlation Coefficient (ECC) of less than 0.05, Diversity Gain (DG) of above 9.8 dB, Mean Effective Gain (MEG) of −3.1 dB, Channel Capacity of 21.50 bps/Hz, and Total Active Reflection Coefficient (TARC) of below −10 dB are achieved by the flexible MIMO smartphone antenna. The effect of bending along the X and Y-axis on the performance of the proposed MIMO antenna is also analyzed where decent performance is observed. This makes the proposed flexible four-element MIMO antenna a potential candidate to be deployed in future smartphones.


2019 ◽  
Vol 8 (3) ◽  
pp. 6-15
Author(s):  
A. Chaabane ◽  
A. Babouri

This paper introduces a novel compact planar Ultra-Wideband (UWB) Multiple-Input-Multiple-Output (MIMO) antenna with dual-band notched performance for Surfaces Penetrating (SP) application. To avoid interference from co-existing systems, two notched bands are introduced by including strips inside the radiating patches. The two ports MIMO antenna is printed on the low-cost FR4 substrate having a compact size of 56×32.47×1.5 mm3. The measured results indicate that the −10 dB bandwidth of the proposed MIMO antenna covers a wide bandwidth from 1.57 GHz to 12.4 GHz (155.05%) with dual-band rejection (2.04 GHz – 3.98 GHz and 4.8 GHz – 6.22 GHz). The effects of numerous construction and decoration surfaces on the antenna’s reflection coefficients are measured. Gypsum, White Portland Cement, Slate, Marble, Wood and Reinforced Concrete were tested. A good penetrating capability is measured which confirms the aptitude of the proposed MIMO antenna to work as SP antenna.


Frequenz ◽  
2018 ◽  
Vol 72 (11-12) ◽  
pp. 503-509
Author(s):  
Rohit Mathur ◽  
Santanu Dwari

Abstract A compact 4-port ultra-wide band (UWB) multiple-input-multiple-output (MIMO) slot antenna with dual polarization is presented. The key features of antenna are: has directive radiation in two planes and low correlation without use of additional decoupling structure. The antenna contains four microstrip feedlines having circular patches backed by stepped circular slots. Orthogonal arrangement of each slot antenna increases compactness with polarization diversity and good isolation. The antenna has compact size of 36×36×0.8 mm3. It operates in the frequency band of 3.1 to 11.9 GHz and isolation is better than 15 dB. The superior diversity performance is ensured by calculating envelope correlation coefficient (ECC) and diversity gain. In addition to guarantee distortion less transmission in UWB group delay is also measured.


2014 ◽  
Vol 6 (3-4) ◽  
pp. 405-413 ◽  
Author(s):  
Oliver Biallawons ◽  
Jens Klare ◽  
Olaf Saalmann

This paper presents the technical realization of the multiple-input multiple-output (MIMO) radar MIRA-CLE Ka (MIMO radar-configurable in Ka-band). This system is a stationary imaging radar without any mechanical moving parts. It is highly portable, ready to use in only a couple of minutes, and it is able to process one radar image per second during continuous radar measurements in the current stage of development. In addition to the image processing, it is possible to detect changes in range of 0.1 mm in the illuminated scene. The MIMO system operates in Ka band and consists of 16 receive and 16 transmit elements, so that 256 virtual elements are generated during signal processing. The size of the antenna's frontend is about 80 cm in width. Owing to its compact size, flexibility, and realtime capability, the system offers a wide field of applications.


Frequenz ◽  
2018 ◽  
Vol 72 (9-10) ◽  
pp. 429-435 ◽  
Author(s):  
Rohit Mathur ◽  
Santanu Dwari

Abstract A compact four port multiple-input-multiple-output (MIMO) antenna with polarization diversity for ultrawideband (UWB) application is proposed. The antenna contains four monopoles where each monopole has three concentric rings. Orthogonal arrangement of monopoles of the antenna provides good isolation and polarization diversity. The antenna has compact size of 36×36×1.6 mm3. It operates in the frequency band of 3.2 to 11 GHz where isolation is better than 15 dB. The envelop correlation coefficient (ECC) and diversity gain from S-parameter have been calculated to evaluate MIMO performance of the antenna. In addition to ensure distortion less transmission in UWB group delay is also calculated.


2017 ◽  
Vol 9 (10) ◽  
pp. 2019-2028 ◽  
Author(s):  
Christoph Dahl ◽  
Michael Vogt ◽  
Ilona Rolfes

In this contribution, fractal antenna arrays are analyzed for their applicability in multiple-input multiple-output (MIMO) radars. Array geometries based on the Fudgeflake fractal and the Gosper island fractal are investigated. In addition, a concept for the combination of both fractals is shown in order to increase the flexibility concerning the number of transmitting and receiving antennas. The presented fractal MIMO concepts can be utilized in order to improve the angular resolution and to reduce the sidelobe level for a given number of transmitting and receiving antennas. It is shown that a fractal MIMO concept with 21 transmitting antennas and 21 receiving antennas improves the angular resolution to 4.6 degrees and reduces side lobe level by 3.1 dB compared to a MIMO configuration based on two linear arrays with the same number of antenna elements. In addition, the results are experimentally validated by broadband radar measurements.


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