Metamaterial inspired quad band circularly polarized antenna for WLAN/ISM/Bluetooth/WiMAX and satellite communication applications

A CPW fed metamaterial inspired Quadband circularly polarized antenna is presented in this article. The proposed antenna consists of defected ground structure with a radiating stub, which is at opposite side of the feedline. A waveguide mode of analysis is carried out for split ring resonator (SRR) and complimentary split ring resonator (CSRR) to enhance the properties of metamaterials. The proposed antenna analysis is taken iteration wise and used FR-4 Material as the substrate material with Ɛ_r = 4.4 and analysed using ANSYS electromagnetic desktop. The designed antenna projecting the peak gain of 4.8 dB and it is working in the application bands of WLAN/ISM/Bluetooth at 2.4 GHz, 5.8 GHz and 3.35 WiMAX band, X-band downlink satellite communication system (7.25–7.75 GHz) and ITU band (8–8.5 GHz) with fractional bandwidth of about 70%. Proposed antenna exhibits circular polarization at 2.39–2.55 GHz, 3.05–3.1 GHz, 4–5 GHz and 6.3–6.64 GHz respectively. To know the signal integrity of the antenna, time domain analysis is carried out for identical antennas in two conditions (face to face and side by side) with the help of CST microwave studio. The designed antenna showing excellent correlation in measurements with respect to simulation results.     

Design of Compact Quad-Band Notched UWB-MIMO Antenna

With quad-notched band characteristic, a compact ultra-wideband (UWB) multiple-input-multiple-output antenna is proposed in the article. There are two identical monopole elements in the system. By inserting symmetrical L-shaped slots, complementary split-ring resonators) and C-shaped stubs in each element, four notched bands are achieved to filter 3.5 GHz WiMAX, 5.25 GHz lower WLAN, 5.8 GHz upper WLAN, and 7.5 GHz X-band. Without decoupling structures, the antennas were placed vertically to obtain high isolation. Results indicate that the antenna operates from 2.6 to 13 GHz except four rejected bands, and port isolation (S21) is better than ?25 dB, envelope correlation coefficient is below 0.002 in UWB spectrum frequency of 3.1–10.6 GHz.     

SRR and S-shape slot loaded triple band notched UWB antenna

This paper demonstrates the design of a triple band notched ultrawideband circular microstrip patch antenna loaded with Complementary Split RingResonator (CSRR) and S-shaped slot in microstrip feed line. Complementary Split Ring Resonator slot and S-shaped slot are used to produce band notched characteristics for WiMAX band (3.30–3.60 GHz) and WLAN band (5.10–5.80 GHz) respectively. The downlink frequency band (7.25–7.75 GHz) of X-band for satellite communication is notched using Symmetrical Split Ring Resonator Pair (SSRRP) as electromagnetic coupling element near microstrip feed line which produces band stop characteristics. Measured results of fabricated antenna prototype are compared with simulated results and found in correspondence. The VSWR and vector current plots show evidence of the significant suppression in the desired frequency bands.     

Compact Quad Band-Notched Monopole Antenna for UWB Systems

A novel compact microstrip-fed UWB antenna with quad notched band is proposed. The antenna consists of a rectangular radiating patch with a half circle, a tapered microstrip feed-line, and a semi-elliptical ground plane. With a pair of L-shaped slots, complementary co-directional SRR and a pair of C-shaped stubs, four notched bands are created to prevent interference from WiMAX/lower WLAN/higher WLAN/X-band. Experimental results show that the designed antenna, with compact size of 20 × 30 mm², has an ultrawide band (VSWR < 2) from 2.68 to 13 GHz, except four notched bands of 3.13–3.8, 4.87–5.52, 5.65–6.1, 7.12–8 GHz. Good radiation patterns and stable gain within the operating band have been observed.     

Triple band notched mushroom and uniplanar EBG structures based UWB MIMO/Diversity antenna with enhanced wide band isolation

Triple band-rejection MIMO/Diversity UWB antenna characteristics are described in this paper. Proposed antenna discards worldwide interoperability for microwave access WiMAX band from 3.3 to 3.6 GHz, wireless local area network WLAN band from 5 to 6 GHz and X-Band satellite downlink communication band from 7.1 to 7.9 GHz. Mushroom Electromagnetic Band Gap (EBG) structures helps to attain band notches in WiMAX and WLAN bands. Uniplanar plus shaped EBG structure is used for notch in X-band downlink satellite communication band. Decoupling strips and slotted ground plane are employed to develop the isolation among two closely spaced UWB monopoles. The individual monopoles are 90° angularly separated with stepped structure which helps to reduce mutual coupling and also contributes towards impedance matching by increasing current path length. Mutual coupling magnitude of more than 15 dB is found over whole UWB frequency range. The Envelope Correlation Coefficient is less than 0.02 over whole UWB frequency range.The variations in the notched frequency with the variations in mushroom EBG structure parameters are investigated.The antenna has been designed using FR-4 substrate and overall dimensions is (64 × 45 × 1.6) mm³.     

基于方开环谐振器的双陷波超宽带滤波器

针对超宽带系统易受窄带信号干扰的问题,设计了一种可以抑制无线局域网络(WLAN)和卫星通信信号干扰的双陷波超宽带带通滤波器。该滤波器的主要谐振结构由T型枝节加载的多模谐振器组成,改进的T型枝节增加了两个传输零点,同时减小了滤波器尺寸;通过耦合方开环谐振器,实现了两个陷波特性,调节谐振器尺寸,可以得到所需的陷波频率。测试结果表明,该滤波器的尺寸仅16.7mm×8.5mm,中心频率为6.9GHz,通带为3.0~10.8GHz,陷波中心频率在5.8GHz和8.04GHz,衰减最低点分别为-27dB和-18dB,仿真与测量结果有较好的一致性。     

A compact wide slot antenna with dual band-notch characteristic for ultra-wideband applications

A new type of ultra-wideband (UWB) antenna with a dual-notched frequency band, compact size of 21?×?28?mm² and a coplanar waveguide (CPW) fed is proposed in this article. Two notched frequency bands are obtained by embedding two U-shaped slots in the radiation patch and a rectangle slot in the ground plane, which can be controlled by adjusting the length of the responding slots. The frequency domain characteristics are investigated and measured. Both the experimental and numerical results show that the proposed antenna has an impedance bandwidth ranging from 3.1?GHz to more than 11.0?GHz in which voltage standing wave ratio is less than 2, expect two notch frequency band, 5–6?GHz (WLAN) and 7.7–8.5?GHz (X-band for satellite communications in China).     

Compact UWB monopole antenna with quadruple band notched characteristics

ABSTRACT

A compact planar Ultrawideband (UWB) monopole antenna with quadruple band notch characteristics is proposed. The proposed antenna consists of a notched rectangular radiating patch with a 50 Ω microstrip feed line, and a defected ground plane. The quadruple band notched functions are achieved by utilising two inverted U-shaped slots, a symmetrical split ring resonator pair (SSRRP) and a via hole. The fabricated antenna has a compact size of 24 mm × 30 mm × 1.6 mm with an impedance bandwidth ranging from 2.86 to 12.2 GHz for magnitude of S₁₁ < ?10 dB. The four band notched characteristics of proposed antenna are in the WiMAX (worldwide interoperability for microwave access) band (3.25–3.55 GHz), C band (3.7–4.2 GHz), WLAN (wireless local area network) band (5.2–5.9 GHz) and the downlink frequency band of X band (7–7.8 GHz) for satellite communication are obtained. The measured and simulation results of proposed antenna are in good agreement to achieve impedance matching, stable radiation patterns, constant gain and group delay over the operating bandwidth.     

A slot resonators based quintuple band-notched Y-shaped planar monopole ultra-wideband antenna

A Y-shaped ultra-wideband (UWB) monopole antenna containing modified ground plane with five stop bands is presented. An inverted U-shaped slot and a C-shaped slot are placed on Y-shaped radiating patch to achieve two notched bands while three pairs of C-shaped slots are placed at different positions on modified ground plane to achieve three more notched bands. The proposed antenna is designed, fabricated and experimentally tested. The designed Y-shaped antenna has overall dimensions of 36 × 38 × 1.6 mm³ (0.34λ_l × 0.36 λ_l × 0.016 λ_l) and has impedance bandwidth 2.86–13.3 GHz at |S₁₁| < −10 dB level. Measured band notches are achieved at 3.75/5.43/7.87/8.62/9.87 GHz centre notched frequencies to eliminate worldwide interoperability for microwave access (WiMAX) band (3.45–4.0 GHz), wireless local area network (WLAN) band (5.15–5.90 GHz), X-band for satellite communication (6.77–8.00 GHz), ITU-8 band (8.3–9.1 GHz), and radio navigation (RN) band (9.3–10.6 GHz), respectively. Variation of slot parameter on individual band notch is also investigated. Omnidirectional radiation pattern for XZ-plane and dipole-like radiation pattern for YZ-plane are observed. Stable gain, variation of phase response in linear fashion and group delay <1.3 ns for whole ultra-wideband except at band notches is achieved.     

一种双阻带椭圆单极子UWB天线的设计

通过仿真与实际测试结合的方法,研究并设计了一种用于UWB通信的、具有双阻带特性的紧凑椭圆单极子天线。双阻带特性是通过在辐射单元上插入一个缝隙和在馈线上引入一共面波导谐振单元实现的。测试结果表明此天线在3.45~3.75 GHz(覆盖了WIMAX频段)和5~6 GHz(覆盖了5.15~5.85 GHz的WLAN频段)分别有两个阻带,此外,驻波系数在3.1~10.6 GHz UWB的范围内小于2。天线的辐射特性也近似于全向。天线的增益和传输函数也证实了天线能达到双阻带特性。     

Design of Compact Planar Triple Band-Notch Monopole Antenna for Ultra-wideband Applications

In this article a microstrip-fed mickey shaped monopole antenna with triple notched band characteristics for ultra-wideband applications is presented. By etching two slots in the ground plane, improved VSWR bandwidth is achieved. Mickey shape radiating patch provides 10 dB return-loss bandwidth from 3.10 to 10.60 GHz. By etching three simple C-shaped slots on the radiating patch, three existing wireless communication systems which interfere with UWB band is removed which includes WiMAX IEEE802.16 (3.30–3.80 GHz), WLAN IEEE802.11a/h/j/n (5.15–5.35, 5.25–5.35, 5.47–5.725, 5.725–5.825 GHz) and X-band downlink satellite system (7.1–7.9 GHz). Experimental results reveal that the proposed antenna exhibits desirable radiation patterns in the far field, resulting omnidirectional like pattern in the H-plane and nearly dipole like pattern in the E-plane.     

Split ring resonator based multiband hybrid fractal antennas for wireless applications

In this paper, initially two Moore Antennas are designed which are different from each other in terms of 50 Ω microstrip transmission line only. Same size Feed line is applied at right and left side of the substrate and termed as Left Side Feed Line (LFL) and Right Side Feed Line (RFL). To improve the multiband behavior of Moore Antenna, it is being fused with Koch curve and resultant antenna is named as Moore – Koch Hybrid Fractal Antenna (MKHFA) where Koch curves are superimposed on Moore curve. Two distinct MKHFA’s are designed as MKHFA with LFL and MKHFA with RFL. In order to attain the more number of frequency bands, improved gain, better impedance matching and improved bandwidth, both the MKHFA’s are loaded with Split Ring Resonator (SRR). Proposed antennas are designed on FR4 glass epoxy substrate with thickness 1.6 mm, relative permittivity 4.4. Results of Moore Antenna has been compared with MKHFA and found that MKHFA exhibits multiband behavior. A comparison between unloaded MKHFA using LFL/RFL and loaded MKHFA using LFL/RFL has been made and found that later case exhibits better results in terms of increase in number of frequency bands, bandwidth enhancement and improvement in gain. Prototypes of proposed MKHFA using LFL loaded with SRR and MKHFA using RFL loaded with SRR have been fabricated and tested for their results. The comparison between the simulated and measured results have been done and found in good agreement with each other. The overall dimensions of proposed MKHFA using LFL/RFL loaded with SRR is 25 mm × 25 mm and can be useful for different wireless applications such as Bluetooth (2.41–2.49 GHz) for ISM band, IEEE 802.11 g/b (2.40–2.48 GHz), WiMAX (2.5–2.69 GHz), WLAN (5.15–5.35 GHz), X-band satellite communication (7.1–7.76 GHz). Proposed MKHFA using LFL loaded with SRR also reports peak gain 5.76 dB and bandwidth 770 MHz, whereas, MKHFA using RFL loaded with SRR confirms peak gain 8.56 dB and bandwidth 750 MHz.     

一种可控三陷波超宽带天线设计与研究

为了避免如WiMax, WLAN和X频段卫星系统等窄带通信系统对超宽带通信系统的影响,该文提出一种具有可控三陷波特性的超宽带天线。该天线通过在辐射贴片和接地板上开槽,并在基板背面增加环形寄生单元的方法实现三陷波特性。天线在3.1~10.6 GHz的超宽带频段内能够有效地工作并抑制3种不同的窄带通信系统的干扰。同时在环形寄生单元处增加开关设置,使天线能够实现双/三陷波的功能切换,并增强陷波性能。实测和仿真结果吻合,该天线实现了良好的陷波功能,在工作频段内有良好的辐射方向特性。     

基于SRR结构的陷波超宽带天线设计

针对超宽带系统易受窄带信号干扰的问题,设计了一种新颖的基于金属开口谐振环(SRR)结构的平面超宽带陷波天线。在天线的辐射贴片上加载U形缝隙,实现了其陷波特性。利用仿真软件研究了U形缝隙的物理尺寸对其陷波特性的影响,并对所设计的超宽带天线进行了制作和测量。结果表明,所制天线在超宽带系统3.1~10.6GHz工作频段的电压驻波比(VSWR)小于2,在WLAN频段具有良好的陷波特性,有效地抑制了超宽带通信系统与窄带通信系统之间潜在的干扰。     

5.2 GHz notched ultra-wideband antenna using slot-type SRR

A band notch characteristic using a slot-type split ring resonator (SRR) working at microwave frequencies is used for designing a UWB antenna requiring the rejection of some frequency band, which is already in use by existing wireless services. The slot-type SRR is employed effectively for notching unwanted frequency band such as that for WLAN service, since it can be implemented with a small dimension and in a high Q operation similarly to the conventional strip-type SRR. Based on the simulation and measurement results, a band notched UWB antenna using a slot-type SRR is very effective in rejecting unwanted frequency in terms of its selectivity and small real estate.     

五陷波超宽带天线的研究与设计

为滤除窄带信号对超宽带通信系统的干扰,研究并设计了一种具有五个陷波特性的超宽带天线。采用微带线馈电,在辐射贴片上刻蚀一个椭圆形开环谐振器,并在馈线旁制作了四个不同尺寸的U 形寄生短截线,以实现天线的陷波特性,天线尺寸为30 mm×40 mm×0.8 mm。仿真实验验证了天线工作频率范围为2.8~12 GHz;有效滤除了WiMAX 波段(2.94~3.42 GHz)、INSAT 波段(4.42~4.53 GHz)、WLAN 波段(5.32~5.5 GHz)、X 波段上行频(7.01~7.27 GHz)和X 波段下行频(7.57~8.05 GHz)。实测数据表明,天线的工作频段、方向性、增益及五个陷波特性等性能指标良好。     

A Quad Band Metamaterial Miniaturized Antenna for Wireless Applications with Gain Enhancement

This paper presents a designing of dual-coated miniaturized metamaterial inspired quad band antenna for wireless standards with gain enhancement. Proposed design has compactness in size with electrical dimension of 0.239?×?0.351?×?0.0127 λ (30?×?44?×?1.6 mm³), at lower frequency of 2.39 GHz. The antenna consist a double printed slotted hexagonal shape radiating section with implementation of metamaterial rectangular split ring resonator. Antenna achieve quad bands for wireless standards WLAN (2.4/5.8 GHz), WiMAX (3.5 GHz), IEEE 802.11P (WAVE-5.9 GHz), ITU assigned X bands (7.25–7.75, 7.9–8.4 GHz) and satellite communication systems operating bands (C-band: 7.4–8.9 GHz and X-band: 8–10 GHz for satellite TV). An acceptable gain, stable radiation characteristics and good impedance matching are observed at all the resonant frequencies of the proposed structure. By application of proposed frequency selective surface an average enhancement of gain is about 4–5 dB over the operating band. Antenna fabricated and tested represent good agreement between the simulated and measured results.

     

Controllable Band‐Notched Slot Antenna for UWB Communication Systems

We propose a slot antenna consisting of a rectangular slot on the ground plane, fed by a microstrip line with a rectangular‐ring‐shaped tuning stub that can be deployed in ultra‐wideband (UWB) communication systems to avoid interference with wireless local area network (WLAN) communication. Our antenna can achieve a single band‐notched property from the 5 GHz frequency to the 6 GHz frequency owing to a controllable band notch that uses L‐ and J‐shaped parasitic elements. The antenna characteristics can be modified to tune the band‐notched property (4 GHz to 5 GHz or 6 GHz to 7 GHz) and the bandwidth of the band notch (1 GHz to 2 GHz). Furthermore, the shifted notch with enhanced width of the band notch from 1 GHz to 1.5 GHz is described in this paper. The UWB slot antenna and L‐ and J‐shaped parasitic elements also provide the band‐rejection function for reference in the WiMAX (3.5 GHz) and WLAN (5 GHz to 6 GHz) regions of the spectrum. Experiment results evidence the return loss performance, radiation patterns, and antenna gains at different operational frequencies.     

Design of novel compact eight-element lotus shaped UWB-MIMO antenna with triple-notch characteristics on hollow substrate

The design of novel compact two-element and eight-element lotus shaped multiple-input-multiple-output (MIMO) antenna system employing pattern diversity with enhanced isolation characteristics is presented. The proposed two-element antenna system is arranged rotationally on a square-hollow substrate resulting in an eight-element MIMO antenna system employing pattern diversity. The developed eight-element MIMO antenna system resonates in the frequency range 3.1 to 14.6 GHz housing the complete UWB band with triple band-notch characteristics at 3.7–4.5 GHz (C-band satellite down link [3.7–4.2 GHz]), 5.1–5.9 GHz (WLAN) and 6.8–8.25 GHz (X-band satellite down link (7.25–7.75 GHz) and up link (7.9–8.4 GHz)) bands. The antenna system gives element-to-element isolation of more than 25 dB in the majority of the operating band with a peak gain of 6.8 dBi and a maximum 90% efficiency. The important MIMO metrics like ECC (envelope correlation coefficient), DG (diversity gain), total active reflection coefficient (TARC), channel capacity losses (CCL) and MEG (mean effective gain) are presented for both two-element and eight-element to estimate the performance the proposed antennas in multi-antenna environments. The both two- and eight-element designs are fabricated and the measured results of those are well agreed with simulation results.     

一种基于开口谐振环的高增益宽带双极化天线设计

该文设计并制作了一种基于超材料的高增益宽带双极化天线,该天线由两个正交放置的印刷振子单元、馈电巴伦及金属接地板构成。为了进一步展宽带宽、提高增益,在天线上了加载开口谐振环、互补开口谐振环等超材料结构。测试结果表明,该天线回波损耗小于-10 dB的带宽约为69%(0.98~2.01 GHz),在相同的频带内隔离度大于20 dB。由于开口谐振环的引向作用,天线的辐射特性得到改善,增益最大提高了4.1 dB左右。和已有设计相比,该天线的总体高度减小了约12%。其可以当作独立天线使用,也可用作反射面天线的双极化馈源。