Frequency notched printed slot antenna with parasitic open-circuit stub

A new frequency notched ultra-wideband microstrip slot antenna with a parasitic tuning stub is proposed. The antenna is similar in configuration to a conventional microstrip slot antenna; by introducing a parasitic open-circuit tuning stub, flexible frequency notched function is achieved. Several properties of the antenna, such as frequency notched function, antenna transfer function and gain, have been investigated. As is reported, the operation bandwidth of the antenna is 2.91-11.16 GHz, in which a frequency notched band of 5.10-5.85 GHz has been achieved. Furthermore, good ultra-wideband linear transmission performance over the entire operation frequency range has also been achieved.     

Circularly polarised microstrip antenna with a tuning stub

A simple circular polarisation (CP) design of microstrip antennas using a tuning stub is proposed and studied. It is also demonstrated that, by applying this CP design method to a circular microstrip patch with a cross slot having equal slot lengths, a compact circularly-polarised microstrip antenna can easily be implemented, with much more relaxed manufacturing tolerances as compared to the case of using a cross slot of unequal slot lengths. Details of the antenna designs are described, and experimental results are presented and discussed     

一种改进的U型槽超宽带微带天线研究

设计了一种改进的U型槽低剖面宽带微带天线,并考虑在尺寸为30.0 mm×30.0 mm×1.5 mm、由相对介电常数为4.4的FR4制成的覆铜介质基板上通过酸蚀制备该天线。利用仿真软件HFSS对该天线的参数进行了仿真和优化,并根据优化的天线尺寸进行了实际制作和测量。仿真及实测结果均表明:通过在U型槽臂加载弧形,该天线的频带宽度和相对带宽分别可达3.4～11.2 GHz(S11≤–10 dB)和107%,达到了展宽带宽的目的。该天线不仅可以实现超宽带,而且结构简单,尺寸小,易于集成。     

Improved U-shaped stub rectangular slot antenna with tuning pad for UWB applications

An improved design of the U-shaped stub rectangular slot antenna with a tuning pad for enhancing the impedance bandwidth is proposed. By properly tuning the physical size of the copper pad, a wide impedance bandwidth of the antenna can be achieved for UWB applications. For 10 dB return loss, a impedance bandwidth of the antenna is covered from 2.3 to 12 GHz (135.7%). A gain variation from 2 to 6.82 dBi is obtained.     

Compact ultra-wideband antenna with tri-band notched characteristic

A compact ultra-wideband printed planar antenna with tri-band notched characteristic is presented. Two different types of slots are used to obtain tri-band notched characteristic. By using a U-slot defected ground structure, a notched band, 5?6 GHz for WLAN, is achieved. An H-shaped slot is etched on the radiating patch to obtain another two notched bands at 3.3?3.7 GHz for WiMAX and 7.2 GHz for some C-band satellite communication systems. The proposed antenna yields an impedance bandwidth of 3.1?10.6 GHz with VSWR , 2, except the notched bands. The antenna is successfully simulated and measured, showing tri-band notched characteristic can be obtained by using two different slots.     

一种双极化的MIMO超宽带方环缝隙天线设计

设计了一种双极化的多输入多输出(MIMO)超宽带方环缝隙天线。该天线有4个天线单元,底层由2个方环微带馈电线构成,用于正交偏振。顶层由2个对称结构的方环构成,用于减少交叉极化。方环之间用矩形切口连接,以增加环缝之间的耦合。测量结果表明,该天线在3~12 GHz内隔离比大于22 d B,相关系数(ECC)在可以接受的范围内。该天线可以应用于MIMO超宽带通信系统中。     

一种新型超宽带微带折线环天线的研究与设计

提出了一种新型折线环形超宽带天线的设计,该天线结构类似一般的宽缝隙天线,不同的是采用了折线环结构进行设计。通过采用折线环结构不仅可以获得宽带工作特性,还能实现尺寸缩减。通过数值分析与实验研究,研究了天线的输入反射特性与辐射特性。计算与实测结果表明,该超宽带天线具有超过4:1的工作带宽以及良好、稳定的全向辐射特性,具有很好的理论参考意义与实用价值。     

一种便携式微带超宽带天线

改进了一种印刷单极U型微带超宽带天线.利用Ansoft公司的高频仿真软件HFSS对影响其辐射性能的关键参数进行了仿真计算,通过优化使其尺寸减少到原来的22%,阻抗带宽也展宽了24%,最后给出了天线的反射损耗曲线和辐射方向图.天线的-10dB反射损耗的频率覆盖范围为2.3～11.2GHz.这种天线不仅适用于短距离超宽带无线通信,而且也适合于无线局域网(WLAN)与蓝牙(BT)通信.     

具有三陷波特性的类Sierpinski分形超宽带天线

为避免窄带通信系统对超宽带(ultra-wideband,UWB)系统的干扰冲突,提出一款具有三陷波特性的类Sierpinski分形UWB天线.辐射贴片采用圆环与五角星形嵌套迭代的2阶类Sierpinski分形结构,并采用缺陷地结构接地板以实现良好的UWB特性.通过在分形结构的上部添加对称倒L形开路枝节,在微带馈线两侧添加对称L形开路枝节,并在馈线处刻蚀倒π形窄缝隙产生了4.5～4.8 GHz、7.2～7.8 GHz和8.0～8.5 GHz三个频段的陷波特性.仿真和实测结果表明,天线在3.1～18.1 GHz的频段内,可有效抑制国际卫星波段、X卫星波段和国际电信联盟波段等窄带系统的干扰.该天线除滤波频段内,在通带频段内有较稳定的增益和全向辐射特性,可用于各种UWB系统中.     

具有三陷波特性的类Sierpinski分形超宽带天线

为避免窄带通信系统对超宽带(ultra-wideband,UWB)系统的干扰冲突,提出一款具有三陷波特性的类Sierpinski分形UWB天线.辐射贴片采用圆环与五角星形嵌套迭代的2阶类Sierpinski分形结构,并采用缺陷地结构接地板以实现良好的UWB特性.通过在分形结构的上部添加对称倒L形开路枝节,在微带馈线两侧添加对称L形开路枝节,并在馈线处刻蚀倒π形窄缝隙产生了4.5～4.8 GHz、7.2～7.8 GHz和8.0～8.5 GHz三个频段的陷波特性.仿真和实测结果表明,天线在3.1～18.1 GHz的频段内,可有效抑制国际卫星波段、X卫星波段和国际电信联盟波段等窄带系统的干扰.该天线除滤波频段内,在通带频段内有较稳定的增益和全向辐射特性,可用于各种UWB系统中.     

Very ultra-wideband printed CPW-fed slot antenna

A very ultra-wideband compact microstrip slot antenna targeting the 3.1-10.6-GHz frequency band is presented. The proposed antenna is a simple printed slot antenna with a novel radiator, which is fed by a 50 Omega CPW line. The measured return loss extends from 2.8-33.4-GHz, about 169-. The proposed antenna has a compact size of 24-25-mm. The measured radiation patterns confirm that the antenna shows an approximately omnidirectional radiation pattern.     

Small dual-frequency microstrip antenna with cross slot

A new design of single-feed, reduced-size dual-frequency rectangular microstrip antenna with a cross slot of equal length is presented. The frequency ratio of the two operating frequencies is mainly determined by the aspect ratio of the rectangular patch, and the reduction in the two operating frequencies is achieved by cutting a cross slot in the microstrip patch. Details of the experimental results for such a design are presented and discussed     

Broadband triangular microstrip antenna with U-shaped slot

The broadband design of a triangular microstrip antenna with a U-shaped slot is demonstrated. With a foam substrate of thickness ~0.08 λ₀, a slotted triangular microstrip antenna with an operating bandwidth of ~18% is obtained, which is ~1.8 times that of a corresponding simple triangular patch antenna. Details of the antenna design and experimental results are presented     

Frequency notched wide slot antenna for UWB/2.4 GHz WLAN applications

A compact frequency notched microstrip slot antenna for ultra-wideband (UWB) /2.4 GHz-band wireless local area network (WLAN) applications is proposed. The antenna is similar to a conventional microstrip slot antenna; however, by introducing a cross wide slot and a meandered-slotted stub, both compact size and frequency notched function can be achieved. It has been studied both numerically and experi- mentally for its impedance bandwidth, surface current distribution, radiation patterns, and gain. As will be seen, an operation bandwidth of over 4.61 ranging from 2.39 to 11.25 GHz for return loss lower than having a frequency notched band ranging from 4.75 to 5.85 GHz has been achieved, and good radiation performance over the entire frequency range has also been achieved.     

A compact quasi-self-complementary dual band notched UWB MIMO antenna with enhanced isolation using Hilbert fractal slot

A compact ultrawideband multiple input multiple output antenna with dual band notch characteristics is proposed. The design utilizes the property of quasi-self-complementary monopoles to achieve a bandwidth that ranges from 2.2 GHz to 11 GHz. The design has a compact size of 30 mm × 41 mm × 1.59 mm. Two quasi-self complementary half circular monopoles are symmetrically arranged to obtain MIMO antenna. Bandnotch characteristics are obtained by adding parasitic strips of Levy's Fractal shape near the feed line. A Hilbert Fractal shaped slot is etched in the ground plane to enhance the isolation (|S₂₁| < −20 dB) throughout the operational bandwidth. The measured and simulated radiation patterns are in good agreement and is found to be stable throughout the ultrawideband. Moreover, the measured peak gain is found to be 4 dBi.     

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.     

具有双陷波特性的蜂窝结构分形超宽带天线

提出了一款具有双陷波特性的蜂窝结构分形超宽带（ultra-wideband，UWB）天线，采用二阶蜂窝结构作为辐射贴片和缺陷地结构接地板实现良好的超宽带特性.通过在辐射贴片上挖去正六边形和矩形宽缝隙并引入对称鱼钩形枝节，在馈线处刻蚀倒U形窄缝隙产生了3.27~4.27 GHz和7.2~8 GHz两个频段的陷波特性.天线在2.8~11.6 GHz的频段内，可有效抑制WiMAX、C波段卫星和X波段卫星窄带系统的干扰.仿真和实测结果基本吻合，表明该天线适合应用于各种UWB通信系统.     

A new ultra-wideband fractal monopole antenna

The paper focuses on the peculiar dynamic behaviour of the recently developed 8 mm² TO-220-packaged, high-voltage, double-interdigitated (or rwo interdigi-tation levels—TIL) GTO thyristor. This novel power device was rated under both slightly and heavily inductive resistive loads, i.e. close to the real conditions encountered in practical power circuits employing GTO thyristors. Emphasis is laid on the ability of TIL GTOs to switch safely, with minimum power losses, a certain amount of anode current under high-voltage conditions and high commutation frequencies. The merits of TIL GTO thyristors are analysed in terms of their reliability and switching efficiency, which include the total power losses (conduction and switching losses), turn-on and turn-off gains and the switching speed. It is shown that thanks to their built-in self-protective features, these novel GTOs possess an enhanced current-handling capability at commutation frequencies up to 50kHz under extremely tough load conditions. The main implications of the results for power applications are outlined.     

C-shaped slot loaded reconfigurable microstrip antenna

A new electronically reconfigurable dual frequency microstrip patch antenna with highly simplified varactor tuning circuitry is presented. The proposed design allows relatively independent selection of the two operating frequencies. Tuning ranges of 7.1 and 4.1% are realised for the two resonant frequencies without the use of any matching circuits.