4-Port Octagonal Shaped MIMO Antenna with Low Mutual Coupling for UWB Applications

A4-port multiple-input multiple-output(MIMO)antenna exhibiting lowmutual coupling andUWBperformance is developed.The octagonal-shaped four-antenna elements are connected with a 50microstrip feed line that is arranged rotationally to achieve the orthogonal polarization for improving the MIMO system performance.The antenna has a wideband impedance bandwidth of 7.5GHz with S11<−10 dB from(103.44%)3.5–11GHz and inter-element isolation higher than 20 dB.Antenna validation is carried out by verifying the simulated and measured results after fabricating the antenna.The results in the form of omnidirectional radiation patterns,peak gain(≥4 dBi),and Envelope Correlation Coefficient(ECC)(≤0.01)are extracted to validate the suggested antenna performance.Aswell,time-domain analysis was investigated to demonstrate the operation of the suggested antenna in wideband applications.Finally,the simulated and experimental outcomes have almost similar tendenciesmaking the antenna suitable for its use in UWBMIMOapplications.

Textile UWB 5G Antenna for Human Blood Clot Measurement

The antenna plays an essential role in the medical industry.The short-range 5th Generation(5G)communication can be used for seamless transmission,reception,patient monitoring,sensing and measuring various processes at high speeds.A passive Ultra Wide Band(UWB)antenna,used as a sensor in the mea-surement of Prothrombin Time(PT)i.e.,blood clot is being proposed.The inves-tigated micro-strip patch UWB antenna operating in the frequency range of 3.1 to 10.6 GHz consists of a circular patch with a diamond-shaped slot made of jeans substrate material with good sensing properties is accomplished by adjusting the copper thickness of the patch.Due to the turbidity in blood plasma,PT measure-ment is the repetitive approach to get accurate value.In order to solve this issue,an antenna is designed,fabricated and analysed to obtain the accurate PT mea-surements from blood plasma.The blood clotting is observed by electromagnetic emitted voltage converted into the frequency range of 5 to 10 GHz and voltage range of 0.66 to 0.87 mV.The circular UWB antenna is constructed employing jean’s substrate with a partial ground plane to improve the S-parameter,gain,bandwidth and performance characteristics.The proposed antenna with Specific Absorption Rate(SAR)value within the acceptable range can be used as a wear-able device in the human body,leveraging 5G technology.This antenna is well suited for various other applications like wireless sensors,wearable devices and short-range communication applications.

Novel band-notched UWB antenna for WUSB system

A simple and compact microstrip-fed ultra wideband （UWB） printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus （WUSB）. The antenna is composed of a U-shaped line radiator and a small strip bar and is partially grounded, so that the measured impedance bandwidth of the antenna is about 7. 88 GHz covering 3. 12 to 11 GHz with VSWR below 2, and the expected band rejection of 5.06 to 5. 89 GHz is also obtained. The characteristics of the proposed antenna are analyzed, and the geometric parameters for optimal performance are investigated in detail. A relatively stable, quasi-omnidirectional and quasi-symmetrical radiation pattern is also found. The proposed band-notched UWB antenna requires no external filters to avoid interference with other systems, and thus, greatly simplifies the system design of an ultra wideband WUSB communication system.

具有高隔离度的紧凑型三陷波UWB-MIMO天线设计

提出了一种具有高隔离度的紧凑型三陷波超宽带(ultra-wideband,UWB)多输入多输出(multiple-input multiple-output,MIMO)天线,整体尺寸为38 mm×26 mm×1.2 mm.通过对辐射贴片底部两侧进行多切角,实现了宽带化;通过在接地板上加载改进的波纹T型去耦结构,并刻蚀倒“π”型槽缝隙,实现了较高隔离度;通过在辐射贴片上刻蚀“U”型缝隙、在馈线上刻蚀类“H”型缝隙以及在右侧引入倒“C”型寄生枝节,实现了WiMAX(3.3~3.6 GHz)、WLAN(5.15~5.85 GHz)和X波段(7.25~7.75 GHz)3个频段的陷波.仿真与测试结果表明,该天线工作频段为2.9~11.3 GHz(相对带宽达到118.31%),隔离度小于-22.6 dB,包络相关系数小于0.01,辐射效率高,辐射特性良好,可以广泛应用于无线通信系统领域中.

Design of a Compact Monopole Antenna for UWB Applications

In this paper,a low cost,highly efficient and low profile monopole antenna for ultra-wideband(UWB)applications is presented.A new inverted triangular-shape structure possessing meander lines is designed to achieve a wideband response and high efficiency.To design the proposed structure,three steps are utilized to achieve an UWB response.The bandwidth of the proposed antenna is improved with changing meander lines parameters,miniaturization of the ground width and optimization of the feeding line.The measured and simulated frequency band ranges from 3.2 to 12 GHz,while the radiation patterns are measured at 4,5.3,6 and 8 GHz frequency bands.The overall volume of the proposed antenna is 26×25×1.6 mm^(3);whereas the FR4 material is used as a substrate with a relative permittivity and loss tangent of 4.3 and 0.025,correspondingly.The peak gain of 4 dB is achieved with a radiation efficiency of 80 to 98%for the entire wideband.Design modelling of proposed antenna is performed in ANSYS HFSS 13 software.A decent consistency between the simulated and measured results is accomplished which shows that the proposed antenna is a potential candidate for the UWB applications.

High Gain of UWB Planar Antenna Utilising FSS Reflector for UWB Applications

In this paper,a high gain and directional coplanarwaveguide(CPW)-fed ultra-wideband(UWB)planar antenna with a new frequency selective surface(FSS)unit cells design is proposed for UWB applications.The proposed UWB antenna was designed based on the Mercedes artistic-shaped planar(MAP)antenna.The antenna consisted of a circular ring embedded with three straight legs for antenna impedance bandwidth improvement.The modelled FSS used the integration of a two parallel conductive metallic patch with a circular loop structure.The FSS provided a UWB stopband filter response covering a bandwidth of 10.5 GHz,for frequencies from 2.2 to 12.7 GHz.The proposed FSS had a compact physical dimension of 5 mm×5 mm×1.6 mm,with a printed array of 19×19 FSS unit cells.The FSS unit cells were printed on only one side of the dielectric FR4 substrate and placed as a sandwich between the antenna and the reflector ground plane.An equivalent circuit configuration(ECC)was used to verify the FSS unit cell structure’s performance.The simulated results indicated that the UWB MAP antenna and FSS reflector provided a fractional bandwidth of 136%and a high gain of 11.5 dB at 8.5 GHz with an acceptable radiation efficiency of 89%.Furthermore,the gain was improved across the operating band and kept between 8.3 and 11.5 dB.The proposed antenna was in good agreement between theoretical and experimental results and offered a wide enough bandwidth for UWB and vehicle applications.

Wearable UWB Antenna-Based Bending and Wet Performances for Breast Cancer Detection

This paper proposed integrating the communication system on the garment,which can be utilized to detect breast cancer at an early stage by using an ultra-wideband(UWB)wearable antenna.Breast cancer is an abnormal cell that is located in the breast tissue.Early detection of breast cancer plays an important role,and it helps in the long term for all women.The proposed UWB wearable antenna successfully operates at 3.1-10.6 GHz under an acceptable reflection coefficient of−10 dB.The fabricated wearable antenna was made from Shieldit Super and felt both conductive and nonconductive wearable materials.Few measurement studies of bending angles have been carried out that covered 2°,4°,6°,8°,and 10°.In addition,the performance of UWB antennas in wet environments is studied in four stages:in water,instantly wet,nearly dry,and entirely dry.There is good agreement between the measured and simulated outcomes.Based on the experimental results,the proposed antenna could be helpful for a home breast cancer detection system.

Miniaturized Novel UWB Band-Notch Textile Antenna for Body Area Networks

This paper presents the design and analysis of a miniaturized and novel wearable ultra-wideband(UWB)band-notch textile antenna for Body Area Networks(BANs).The major goal of building the antenna for wearable applications with band notch in X-band is to reject the downlink band(7.25 to 7.75 GHz)of satellite communication in the UWB frequency ranges of 3.1–10.6 GHz to keep away from interference.Computer Simulation Technology(CST)TM Microwave Studio,which is user-friendly and reliable,was used to model and simulate the antenna.The radiating element of the antenna is designed on Jeans’textile substrate,which has a relative permittivity of 1.7.The thickness of the jeans’fabric substrate has been considered to be 1 mm.Return loss,gain,bandwidth,impedance,radiation,and total efficiency,and radiation patterns are presented and investigated.The antenna is simulated placed on the three layers of the human body model,and the on-body results are summarized in comparison with free space.Results and analysis indicate that this antenna has good band-notch characteristics in the frequency range of 7.25 GHz to 7.75 GHz.The parametric study varying the relative permittivity of Jeans’fabric substrate of this antenna is also evaluated.In addition,effects on the antenna parameters of variation of ground plane size have been reported.The antenna is 25 mm×16 mm×1.07 mm in total volume.Results reveal that this antenna achieves the design goal and performs well both in free space and on the body.

Frequency-Agile WLAN Notch UWB Antenna for URLLC Applications

This paper introduces a compact dual notched UWB antenna with an independently controllable WLAN notched band integrated with fixed WiMAX band-notch.The proposed antenna utilizes a slot resonator placed in the main radiator of the antenna for fixed WiMAX band notch,while an inverted L-shaped resonator in the partial ground plane for achieving frequency agility within WLAN notched band.The inverted L-shaped resonator is also loaded with fixed and variable capacitors to control and adjust the WLAN notch.The WLAN notched band can be controlled independently with a wide range of tunability without disturbing the WiMAX bandnotch performance.Step by step design approach of the proposed antenna is discussed and the corresponding mathematical analysis of the proposed resonators are provided in both cases.Simulation of the proposed antenna is performed utilizing commercially available 3D-EM simulator,Ansoft High Frequency Structure Simulator(HFSS).The proposed antenna has high selectivity with experimental validation in terms of reflection coefficient,radiation characteristics,antenna gain,and percentage radiation efficiency.The corresponding measured frequency response of the input port corresponds quite well with the calculations and simulations in both cases.The proposed antenna is advantageous and can adjust according to the device requirements and be one of the attractive candidates for overlay cognitive radio UWB applications and URLLC service in 5G tactile internet.The proposed multifunctional antenna can also be used for wireless vital signs monitoring,sensing applications,and microwave imaging techniques.

High Gain UWB Four Elements Antenna Array for C-Band and X-Band Application

The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by International Telecommunication Union. The X-band is used for terrestrial broadband communication, radar applications, and portions of the X-band are assigned for deep space telecommunications. In this paper, a design of 4 × 1 Ultra Wide Band (UWB) antenna array for C-band and X-band applications is introduced. Metamaterial sixteen-unit cells are incorporated into each antenna element for radiation characteristics enhancement purposes. Permeability and permittivity of metamaterial unit cells are obtained all over the operating bandwidth. UWB unequal power divider is used to feed the proposed four elements antenna array based on Chebyshev excitation method. The proposed antenna has a suitable 3 dB beam width and gains all over the operating bandwidth which extends from 5.6 GHz to 10.9 GHz. The proposed antenna covers 60% and 72.5% of the C-band and X-band, respectively. The proposed antenna is fabricated, measured, and good agreement is obtained between simulated and measured results. The obtained performance ensures the suitability of the proposed antenna array for C-band and X-band applications.

A Compact Ultra-Wideband Circularly Polarized Antenna Array for Vehicular Communications

In this paper,a new compact ultrawideband(UWB)circularly polarized(CP)antenna array for vehicular communications is proposed.The antenna array consists of a 2×2 sequentially rotated T-shaped cross dipole,four parasitic elements,and a feeding network.By loading the T-shaped cross dipoles with parasitic rectangular elements with cut corners,the bandwidth can be expanded.On this basis,the radiation pattern can be improved by the topology with sequential rotation of four T-shaped cross-dipole antennas,and the axial ratio(AR)bandwidth of the antenna also can be further enhanced.In addition,due to the special topology that the vertical arms of all Tshaped cross dipoles are all oriented toward the center of the antenna array,the gain of proposed antenna is improved while the size of the antenna is almost the same as the traditional cross dipole.Simulated and measured results show that the proposed antenna has good CP characteristics,an impedance bandwidth for S11<-10 d B of about 106.1%(3.26:1,1.57-5.12 GHz)and the 3-d B AR bandwidth of about 104.1%(3.17:1,1.57-4.98 GHz),a wide 3-d B gain bandwidth of 73.3%as well as the peak gain of 8.6 d Bic at 3.5 GHz.The overall size of antenna is 0.56λ×0.56λ×0.12λ(λrefers to the wavelength of the lowest operating frequency in free space).The good performance of this compact UWB CP antenna array is promising for applications in vehicular communications.

The Design of UWB Antenna for Mobile Phone and the Antenna Influence on Human Head Model

In order to improve the performance of the antenna at low frequency,short circuit branch and coupling feed structure are introduced into the folded broadband single antenna in this paper,then resonant frequency is merged into the antenna using method of stagger tuning,finally,a UWB antenna is designed to w ork betw een 800 MHz ~ 2700 MHz. Analysis are conducted to determine the antenna's properties. The short-circuit w ire location,feeding point location and the length of folded strip are discussed in detail. The SAR is calculated by HFSS simulation softw are w hile the antenna is close to a 3D human head model. The research results show that the antenna can cover eight commonly used commercial frequency bands at present,and electromagnetic radiation of the antenna has tiny influence on the human head model.

New band-notched UWB antenna

A simple and compact ultra wideband （UWB） printed monopole antenna with band-notched performance is proposed in this paper. The antenna is partially grounded so that the Q value is depressed and the impedance bandwidth is broadened. A small strip bar is loaded on each arm of the similar U-shaped radiator. The impedance bandwidth of the antenna overlap with IEEE 802.11a is rejected consequently. The geometry parameters of the antenna are investigated and optimized with HFSS. The measured bandwidth of the proposed antenna occupies about 7.89 GHz covering from 3.05 GHz to 10.94 GHz with expected notched band from 4.96 GHz to 5.98 GHz. A quasi-omnidirectional and quasi-symmetrical radiation pattern in the whole band is also obtained. As a result, a UWB wireless communication system can be simplified with the band-notched UWB antenna presented.

一种具有陷波特性的多模态频率可重构UWB天线

为了应对在超宽带(Ultra-Wide Band, UWB)系统中频率可重构天线尺寸偏大、模式单一等问题,提出了一种具有陷波特性的多模态频率可重构UWB天线。该天线通过在圆形单极子的辐射贴片上添加T型枝节和刻蚀I型槽、倒U型槽,以获得UWB覆盖范围为2.7~11.6 GHz的宽阻抗带宽,并产生四个陷波带。仿真与实测表明:控制PIN二极管的偏置状态,可以实现单频段、双频段、三频段、四频段和五频段共五种频段下八种工作模式的多模态切换。此天线大小为16 mm×19 mm,较传统单极子天线体积减小了40%以上,实现了小型化。天线的最大增益为4.13 dBi,具有良好的辐射特性。

Optimization of band-notched UWB antenna using micro-genetic algorithm combined with FDTD

The micro-genetic algorithm (MGA) optimization combined with the finite-difference time-domain (FDTD) method is applied to design a band-notched ultra wide-band (UWB) antenna. A U-type slot on a stepped U-type UWB monopole is used to obtain the band-notched characteristic for 5 GHz wireless local area network (WLAN) band. The measured results show that voltage standing wave ration (VSWR) less than 2 covers 3.1-10.6 GHz operating band and VSWR more than 2 is within 5.150-5.825 GHz notched one with the highest value of 5.6. Agreement among the calculated, HFSS simulated and measured results validates the effiectiveness of this MGA-FDTD method, which is efficient for UWB antennas design.

DESIGN OF CPW-FED ASYMMETRIC SLOT UWB ANTENNA FOR WIRELESS APPLICATION

A compact Ultra-WideBand(UWB) slot antenna is presented in this paper. The slot is modified rectangular in shape and asymmetrically cut in the ground plane. A hexagonal patch with two stepped CoPlanar Waveguide(CPW) feed is used to excite the slot. Wider impedance bandwidth is achieved due to the extra inductive reactance created by the asymmetric slot which neutralizes the capacitive reactance of the hexagonal patch. The measured impedance bandwidth of the proposed antenna is 11.85 GHz(2.9–14.75 GHz). The radiation patterns of the proposed antenna are obtained and found to be omni-directional in H-plane and bi-directional in E-plane.

一种小型化五陷波UWB天线设计

为了滤除窄带信号对超宽带(Ultra-Wide Band,UWB)通信系统的干扰以及解决天线尺寸偏大的问题,设计出一种小型化五陷波UWB天线。该天线通过添加L型枝节、C型槽、倒U型槽以及EBG结构,产生五个陷波带。对天线进行回波损耗(S11)、驻波比(VSWR)以及增益(Gain)等仿真测试,通过天线表面的电流分布情况分析了天线的陷波原理,研究上述结构对天线陷波特性的影响。该天线将UWB通信应用与陷波天线技术相结合,最终尺寸为21 mm×16 mm,实现了体积小、频带宽、多频段陷波特性的性能要求,天线频带覆盖了S、C和X三个波段,具有屏蔽窄带信号干扰的作用,可应用于UWB通信系统。测试结果表明,天线的阻抗带宽为2~12 GHz,在工作频段内具有全向性,并且整个UWB频段内天线的增益变化在4 dB以内,最大增益为4.67 dB,在通带频段内,天线五个陷波特性的结果与仿真结果均吻合良好。

A Frequency Selective Surface Loaded UWB Antenna for High Gain Applications

This paper presents the design of wideband and high gainFrequency Selective Surface(FSS)loaded antenna for ultra-wideband(UWB)wireless applications requiring high-gain.The antenna consists of a monopole and an FSS reflector.Initially,a conventional rectangular monopole antenna is modified using slot and stub to achieve wide operational bandwidth and size reduction.This modified antenna shows 50%miniaturization compared to a primary rectangular monopole,having a wide impedance bandwidth of 3.6-11.8 GHz.Afterward,an FSS is constructed by the combination of circular and square ring structures.The FSS array consisting of 8×8-unit cells are integrated with the antenna as a reflector to enhance the performance of the proposed miniaturized UWB antenna.The loading of FSS results in an improvement of at least 4 dBi gain in the entire operational bandwidth.Moreover,the antenna’s bandwidth is also increased at the lower frequency band due to the presence of the FSS.A prototype of the antenna is fabricated and tested to verify the simulation results.The simulation and measurement results show that the antenna offers a wideband-10 dB impedance bandwidth ranging from 2.55-13GHz with a stable peak gain of 8.6 dBi and retains the radiation pattern stability.

Triple Notched Band Characteristics UWB Antenna Using C-Shaped Slots and Slot-Type Capacitively-Loaded Loop (CLL)

Ultra wide bands antennas with notched bands characteristics have recently been considered for efficient communication between devices. In this paper, a compact ultra-wideband antenna (UWB) for UWB applications with triple bandnotched characteristics is presented. The proposed antenna consists of a square patch with four truncated corners and a partial ground plane with a rectangular slit. The operation bandwidth of the designed antenna is from 2.66 GHz to more than 13.5 GHz. Band-notched characteristics of antenna to reject the frequency band of 3.18 - 3.59 GHz and 4.70 - 5.88 GHz, is realized by inserting two C-shaped slots in the patch, the third band of 9.54 - 12.22 GHz is achieved by slottype capacitively-loaded loop (CLL) inserted in the patch near the feed line. Details of the proposed antenna design and simulated results are presented and discussed.

Design and Implementation of Step-Constant Tapered Slot Antennas for UWB Application

This paper presents the analytical design and high performance of step-constant tapered slot antenna (STSA) for ultra-wideband application. The return loss, radiation pattern, antenna gain, and level of cross polarization of this antenna are presented and analyzed. Utilizing Rogers (RO3006) substrate having a relative permittivity of 6.15, the proposed antenna provides the ultra-wideband (UWB) from 3.1 GHz to 10.6 GHz. It is observed that the return loss and gain are increased with increasing the step size. It has been observed from the simulation results incorporating CST microwave studio commercial software version 2015, the optimum return loss, directivity and gain are ?43 dB, 10.52 dBi and 10.20 dB, respectively, for 15 step size. Therefore, the newly proposed antenna will be a decent candidate for ultra-wideband application.