scholarly journals Compact Four-Port Dual-Sense Circularly Polarized Stack-Up Patch Antenna for UHF/MW-RFID MIMO System

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.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Enze Zhang ◽  
Andrea Michel ◽  
Paolo Nepa ◽  
Jinghui Qiu

A compact, low-profile, two-port dual-band circularly polarized (CP) stacked patch antenna for radio-frequency identification (RFID) multiple-input-multiple-output (MIMO) readers is proposed, which employs the shared-aperture technique. The proposed antenna adopts a 1.524 mm thickness Rogers Ro4350b substrate with relative permittivity of 3.48. Two pairs of isolated ports are working at two microwave- (MW-) RFID bands (2.4–2.485 GHz and 5.725–5.875 GHz) with high port isolation of 25 dB and 30 dB, respectively. A shared metal slot layer is designed to separate two feeding structures of the lower band and upper band for port isolation enhancement as well as saving space. Corner-truncated square slot and patch configurations have been designed to obtain CP modes. In the lower and upper MW-RFID bands, the relative impedance bandwidths are 12.2% and 5.7%, and the maximum realized gains are higher than 7.3 dBic. Moreover, two-element configurations have been combined for an RFID MIMO system that occupies a dimension of 119 mm × 119 mm × 12.9 mm. The MIMO antenna performance of envelope correlation coefficient (ECC) is lower than 0.03, and diversity gain is close to 10 dB.


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.


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.


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.


Author(s):  
Charles MacWright Thomas ◽  
Huda A. Majid ◽  
Zuhairiah Zainal Abidin ◽  
Samsul Haimi Dahlan ◽  
Mohamad Kamal A. Rahim ◽  
...  

<p>A study on the V-shaped microstrip patch antenna for multiple-input multiple-output (MIMO) communication system based on the antenna orientation is performed. First the microstrip patch antenna operating at 2.45 GHz is calculated and simulated. Next, multiple element of antennas for MIMO system is simulated and discussed. V-shaped with 45 degree slanted inward and outward is studied. The antenna properties is analyzed and compact antenna design is determined based on the simulation results. The results shows the gap between antennas can be optimized to 1 mm while maintaining low mutual coupling. The gain of the MIMO antenna is 8.42 dBi. The simulated return losses, together with the radiation patterns, are presented and discussed.</p>


Author(s):  
Pavithra S ◽  
AmeeliaRoseline A

In MIMO(multiple input multiple output) system, antenna performance are degraded by mutual coupling hence to overcome this we go for circular polarization. In this paper we use planar, circularly polarized MIMO patch with three grounded stubs, F-shaped mirrored structure to achieve same time isolation &matching with offset feeding between two patches for circularly polarization.The elements of antenna are closely packed with 0.06λ0 of edge to edge distance at 2.5 GHZ frequency. The proposed antenna will results the impedance matching S11 < -10 dB and high isolation of S12 < -20 dB.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Wenjing Wu ◽  
Bo Yuan ◽  
Aiting Wu

A compact planar quad-element ultrawideband (UWB) antenna with a band-notch and low coupling for multiple-input multiple-output (MIMO) system is proposed in this paper. The antenna consists of four circular monopoles with modified defected ground plane and a periodic electromagnetic band gap (EBG) structures. The proposed EBG structures are modified from the traditional mushroom-like ones, comprised of patterns of grids on the top patch, the metallic ground plane, and several vias that connect the top and bottom plane. It is printed at the center of the dielectric substrate to lower electromagnetic coupling between the parallel elements. Besides, by etching four crescent ring-shaped resonant slots on the radiators, a sharp band-notched characteristic is achieved. From the experimental results, the −10 dB bandwidth of the antenna is extended covers from 3.0 to 16.2 GHz, with a sharp notched band at 4.6 GHz. And the isolation is greater than 17.5 dB between its elements, with a peak gain of 8.4 dB and a peak efficiency of 91.2%. Moreover, it has a compact size of 0.6λ×0.6λ×0.016λ at 3 GHz and could be a good candidate for portable devices.


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