A simple and effective broadband decoupling structure for UWB-MIMO antenna

2021 ◽  
pp. 1-6
Author(s):  
Huiqing Zhai ◽  
Kunming Zhang ◽  
Yu Huo ◽  
Chaozong Guo
Keyword(s):  
Common Ground ◽  
Impedance Matching ◽  
Antenna Element ◽  
Portable Devices ◽  
Excellent Performance ◽  
Mimo Antenna ◽  
Measurement Results ◽  
New Type ◽  
Better Than ◽  
Microstrip Feed

Abstract A new type of closed square ring decoupling structure is proposed in this letter, which can effectively reduce the coupling of antennas. The designed antenna is composed of two elliptical monopoles and a common ground loaded with a broadband parasitic decoupling structure. Considering the impedance matching, each antenna element is changed from the original rectangular microstrip feed to a tapered microstrip feed and etched a circular slot on the elliptical monopole patch. By comparison with the original antenna without any decoupling structure, through loading the broadband decoupling structure on the ground, the antenna isolation is improved by 10 dB in most frequency bands. Comparing simulation and measurement results, the antenna achieves better than 25 dB isolation over the whole operating band (3.3–12 GHz). By manufacturing and testing the antenna designed in this article, the excellent performance parameters obtained also prove that the antenna can be used in portable devices.

scholarly journals A High Isolation MIMO Antenna without Decoupling Structure for LTE 700 MHz

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Yanjie Wu ◽  
Yunliang Long
Keyword(s):  
Impedance Matching ◽  
Multiple Input Multiple Output ◽  
Monopole Antenna ◽  
Antenna Element ◽  
Mimo Antenna ◽  
High Isolation ◽  
Antenna Performance ◽  
Measurement Results ◽  
Multiple Input ◽  
Input Multiple Output

This paper presents a long-term evolution (LTE) 700 MHz band multiple-input-multiple-output (MIMO) antenna, and high isolation between the two symmetrical antenna elements is obtained without introducing extra decoupling structure. Each antenna element is a combination antenna of PIFA and a meander monopole antenna. The end of the PIFA and the meander monopole antenna are, respectively, overlapped with the 50 Ω microstrip feed line, the two overlapping areas produce additional capacitance which can be considered decoupling structures to enhance the isolation for the MIMO antenna, as well as the impedance matching of the antenna elements. The MIMO antenna is etched on FR4 PCB board with dimensions of 71 × 40 × 1.6 mm3; the edge-to-edge separation of the two antenna elements is only nearly 0.037 λat 700 MHz. Both simulation and measurement results are used to confirm the MIMO antenna performance; the operating bandwidth is 698–750 MHz withS11≤−6 dB andS21≤−23 dB.

scholarly journals A compact disc loaded curved elliptical shaped ultra-wideband MIMO antenna

2018 ◽  
Vol 7 (2.7) ◽  
pp. 597
Author(s):  
EVV Satyanarayana ◽  
Vivek Kumar ◽  
D Mallikarjun Reddy ◽  
T Siva Paravathi ◽  
J Chandrasekhar Rao
Keyword(s):  
Common Ground ◽  
Coplanar Waveguide ◽  
Impedance Matching ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Wide Band ◽  
Ultra Wideband ◽  
Portable Devices ◽  
Mimo Antenna ◽  
Uwb Applications

The ultra wide band (UWB) Multiple-Input- Multiple-Output (MIMO) antenna with coplanar waveguide (CPW) having size of 18 x 23 x 0.8mm3 is designed for ultra-wideband (UWB) applications. The designed MIMO antenna contains two symmetrical circular disc loaded curved elliptical monopoles on top of the substrate and common ground plane with Y slot and extended T-shaped stub on bottom of substrate. The T- shape stub is placed on the ground plane to have the better antenna impedance matching and to enhance the isolation between the two antenna ports. To further improve the isolation in between the ports 1 and 2, and also on the ground plane a Y-shaped slot is fixed. Good impedance matching (|S11| < -10dB) in the range from 2.8GHz to 12 GHz is provided by the proposed antenna, and an enhanced isolation of -27dB, low ECC of below 0.002, an acceptable gain of about 7 dBi and an efficiency of above 90%. The obtained result proves that the designed antenna is more appropriate for the portable devices.  

Compact LowPass Filter with Wide StopBand Using Non-Uniform Microstrip Resonant Cells

2012 ◽  
Vol 263-266 ◽  
pp. 15-19
Author(s):  
Yan Liang ◽  
Xiao Ming Wu ◽  
Bi Hua Tang ◽  
Yong Le Wu
Keyword(s):  
Microstrip Line ◽  
Photonic Bandgap ◽  
Impedance Matching ◽  
Stop Band ◽  
Cutoff Frequency ◽  
Harmonic Suppression ◽  
Lowpass Filter ◽  
Measurement Results ◽  
Better Than

In this paper, a novel compact microstrip lowpass filter is designed. The proposed filter which is etched on the 50 Ω microstrip line consists of four non-uniform 1-D microstrip photonic bandgap (PBG) cells with different cutoff frequency.. The demonstration lowpass filter with 2.2 GHz cutoff frequency is designed, fabricated and measured. The measurement results show that the band rejection effect is better than -20 dB from 2.8 GHz to 10 GHz, the insertion is less than 2 dB, and the length of filter is 5.6 cm long. Compared with the conventional filter, the proposed filter has smaller size. Meanwhile, it overcomes the problems of narrow stop-band and low harmonic suppression. Furthermore, the impedance matching is not need to be considered. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.

Dual circularly polarized multilayer MIMO antenna array with an enhanced SR-feeding network for C-band application

2017 ◽  
Vol 9 (8) ◽  
pp. 1741-1748 ◽  
Author(s):  
Mahdi Jalali ◽  
Mohammad Naser-Moghadasi ◽  
Ramezan Ali Sadeghzadeh
Keyword(s):  
Antenna Array ◽  
Tai Chi ◽  
Impedance Matching ◽  
Axial Ratio ◽  
Wide Band ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Circularly Polarized ◽  
Mimo Antenna ◽  
Feed Network

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.

scholarly journals Design of a Compact MIMO Antenna Using Coupled Feed for LTE Mobile Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xing Zhao ◽  
Youngki Lee ◽  
Jaehoon Choi
Keyword(s):  
Correlation Coefficient ◽  
Mobile Applications ◽  
Return Loss ◽  
Impedance Matching ◽  
Antenna Element ◽  
Mimo Antenna ◽  
First Order ◽  
Term Evolution ◽  
Radiating Element

A compact multi-input multi-output (MIMO) antenna with a coupled feed structure for 4th generation (4G) handsets is proposed for operation in long-term evolution (LTE) band 13 (0.746 GHz–0.787 GHz). The MIMO antenna consists of two symmetrically distributed identical antenna elements. The size of each element is limited to 20 mm × 10 mm × 5 mm (λ0=392 mm at 0.765 GHz), and the separation between different elements is minimized to 15 mm. Each antenna element contains a Z-shaped coupled feed strip and a simple folded monopole-type radiating element. The simple folded radiating element supports two monopole modes (first order) excited at adjacent frequencies to achieve broadband performance. The coupled feed strip effectively modifies impedance matching and maintains good isolation. The proposed antenna has a 6 dB return loss bandwidth of 55 MHz (0.735 GHz–0.79 GHz) and isolation above 12 dB without the use of an additional isolation enhancement element. Moreover, the envelope correlation coefficient (ECC) is maintained below 0.5 over the designed frequency band.

scholarly journals A Quad-Port Dual-Band MIMO Antenna Array for 5G Smartphone Applications

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 542 ◽  
Author(s):  
Jianlin Huang ◽  
Guiting Dong ◽  
Jing Cai ◽  
Han Li ◽  
Gui Liu
Keyword(s):  
Antenna Array ◽  
Dual Band ◽  
Antenna Element ◽  
Total Efficiency ◽  
Smartphone Applications ◽  
Mimo Antenna ◽  
Single Antenna ◽  
Fifth Generation ◽  
5 Ghz ◽  
Better Than

A quad-port antenna array operating in 3.5 GHz band (3.4–3.6 GHz) and 5 GHz band (4.8–5 GHz) for fifth-generation (5G) smartphone applications is presented in this paper. The single antenna element consists of an L-shaped strip, a parasitic rectangle strip, and a modified Z-shaped strip. To reserve space for 2G/3G/4G antennas, the quad-port antenna array is printed along the two long frames of the smartphone. The evolution design and the analysis of the optimal parameters of a single antenna element are derived to investigate the principle of the antenna. The prototype of the presented antenna is tested and the measured results agree well with the simulation. The measured total efficiency is better than 70% and the isolation is larger than 16.5 dB.

scholarly journals Double Overt-Leaf Shaped CPW-Fed Four Port UWB MIMO Antenna

Electronics ◽  
2021 ◽  
Vol 10 (24) ◽  
pp. 3140
Author(s):  
Shobit Agarwal ◽  
Umair Rafique ◽  
Rizwan Ullah ◽  
Shakir Ullah ◽  
Salahuddin Khan ◽  
...  
Keyword(s):  
Frequency Band ◽  
Impedance Matching ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Antenna Element ◽  
Single Element ◽  
Mimo Antenna ◽  
Single Antenna ◽  
Isolation Performance ◽  
Diversity Technique

This paper presents a 4 × 4 multi-input multi-output antenna array for ultra-wideband applications. The single element of the array is comprised of a modified co-planar waveguide-fed double overt-leaf shaped patch radiator. The co-planar ground is optimized to achieve maximum impedance matching in the operating frequency band. The results show that the single antenna element offers an impedance bandwidth of 13.2 GHz starting from 3.2 GHz to 16.7 GHz. It is also observed from the results that the antenna offers good radiation characteristics and acceptable gain for the frequency band of interest. Furthermore, a 4 × 4 MIMO array is designed by utilizing the polarization diversity technique. To improve the isolation performance among antenna elements, a fan-shaped decoupler is introduced on the other side of the substrate, which ensures minimum isolation of 20 dB. Moreover, the proposed MIMO array operates in the frequency range of 2.75–16.05 GHz. The proposed MIMO array is fabricated and measured for the validation of simulation results, and it is observed that both the results are well in agreement.

scholarly journals Reduction of Mutual Coupling in UWB/MIMO Antenna Using Stub Loading Technique

2021 ◽  
Vol 17 (1) ◽  
pp. 12-18
Author(s):  
Adamu Halilu Jabire ◽  
Anas Abdu ◽  
Sani Saminu ◽  
Sani Salisu ◽  
Abubakar Muhammad Sadiq ◽  
...  
Keyword(s):  
Mutual Coupling ◽  
Impedance Matching ◽  
Ground Plane ◽  
Surface Current ◽  
Uwb Antenna ◽  
Mimo Antenna ◽  
Capacity Loss ◽  
Measurement Results ◽  
Uwb Applications ◽  
Mutual Coupling Reduction

Abstract The research presents mutual coupling reduction between UWB-MIMO antenna elements using stub loading technique. The proposed 2 × 2 UWB antenna geometry consists of two circular-shaped monopole radiators with a partial ground for perfect impedance matching. Stubs of 20 mm × 0.2 mm are inserted between the two antenna elements in the ground plane to improve the isolation. The decoupling stub leads to a mutual coupling reduction of less than 20 dB. The farfield measurement at a selected frequency of 10 GHz confirms an omnidirectional radiation pattern. Different MIMO antenna metric such as channel capacity loss (CCL), mean effective gain (MEG), total active reflection coefficient (TARC), envelope correlation coefficient (ECC), and surface current are presented. Details of the design considerations and the simulation and measurement results are presented and discussed. The proposed MIMO antenna array can be well suited for UWB applications.

scholarly journals CPW Fed Compact UWB 4-Element MIMO Antenna with High Isolation

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2688
Author(s):  
Wenfei Yin ◽  
Shaoxiang Chen ◽  
Junjie Chang ◽  
Chunhua Li ◽  
Salam K. Khamas
Keyword(s):  
Impedance Matching ◽  
Ground Plane ◽  
Multiple Input Multiple Output ◽  
Polarization Diversity ◽  
Mimo Antenna ◽  
High Isolation ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Uwb Applications ◽  
Better Than

In the paper, an extremely compact multiple-input-multiple-output (MIMO) antenna is proposed for portable wireless ultrawideband (UWB) applications. The proposed prototype consists of four monopole antenna elements, which are placed perpendicularly to achieve polarization diversity. In addition, the mutual coupling between antenna elements is suppressed by designing the gap between the radiation element and the ground plane. Moreover, a matching stub has been connected to the feedline to ensure impedance matching in high frequency. Both simulated and measured results indicate that the proposed antenna has a bandwidth of 3–20 GHz, with a high isolation better than 17 dB. In addition, the designed MIMO antenna offers excellent radiation characteristics and stable gain over the whole working band. The envelope correlation coefficient (ECC) is less than 0.1, which shows that the antenna can meet the polarization diversity characteristics well.

scholarly journals A balanced-to-balanced directional coupler based on branch-slotline coupled structure

Frequenz ◽  
2020 ◽  
Vol 74 (11-12) ◽  
pp. 427-433
Author(s):  
Yaxin Liu ◽  
Feng Wei ◽  
Xiaowei Shi ◽  
Cao Zeng
Keyword(s):  
Directional Coupler ◽  
Return Loss ◽  
Design Method ◽  
Differential Mode ◽  
Arbitrary Power ◽  
Measurement Results ◽  
Transition Structures ◽  
Coupled Structures ◽  
Better Than ◽  
Good Agreement

AbstractIn this paper, a balanced-to-balanced (BTB) branch-slotline directional coupler (DC) is firstly presented, which can realize an arbitrary power division ratios (PDRs). The coupler is composed by microstrip-to-slotline (MS) transition structures and branch-slotline coupled structures. The single-ended to balanced-ended conversion is simplified and easy to implemented by the MS transition structures, which intrinsically leads to the differential-mode (DM) transmission and common-mode (CM) suppression. Moreover, the different PDRs which are controlled by the widths of branch-slotlines can be achieved. In order to verify the feasibility of the proposed design method, two prototype circuits of the proposed coupler with different PDRs are fabricated and measured. The return loss and the isolation of two designs are all better than 10 dB. Moreover, the CM suppressions are greater than 35 dB. A good agreement between the simulation and measurement results is observed.

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