Unbalanced-Mode Spiral Antenna Backed by an Extremely Shallow Cavity

This paper describes a two-arm Archimedean spiral antenna backed by a conducting cavity, where only one arm is directly excited, with the other arm being parasitically excited; in other words, the spiral arms are excited in an unbalanced mode. A balun circuit required for a conventional two-arm spiral is not used for this unbalanced-mode spiral. The design of the unbalanced-mode spiral is performed over a frequency range of $f _{rm Ld} = 3~{rm GHz}$ to $f _{rm Hd} = 9~{rm GHz}$ (1:3 bandwidth), where the antenna height is selected to be extremely small ($7~ {rm mm}= 0.07$ wavelength at $f _{rm Ld}$) to realize a low-profile antenna. For reference, a corresponding spiral antenna excited in balanced mode is also analyzed. It is found that the unbalanced-mode spiral shows an acceptably small VSWR over the design frequency range of $f _{rm Ld}$ to $f _{rm Hd}$. The radiation is circularly polarized around the antenna axis normal to the spiral plane. The gain shows behavior similar to that of the balanced-mode spiral. Results for other antenna heights (5 mm, 10.5 mm, and 14 mm) are also presented and briefly discussed. It can be said that the unbalanced-mode spiral is a circularly polarized wideband antenna with a simple feed system.      

WLAN双频印刷天线的设计

设计了一种应用于2.4GHz和5.8GHz无线局域网的双频天线。天线由4个印刷偶极子分别组成两对阵列而成,每一对阵列分别工作在各自的谐振频率上,从而实现双频。介质板背面印刷有巴伦进行耦合馈电。该天线具有结构简单、体积小、重量轻,成本低、易于集成等优点,适用于无线局域网系统。     

Defected Ground Based Fractal Antenna for S and C Band Applications

Wireless Personal Communications - Defected ground based modified rectangular fractal patch antenna for mobile devices communication in Delay Tolerant Networks, Wireless sensor networks and Mobile...     

A Compact Rectangular Dual Patch Antenna for Multiple Satellite Communication Applications

At present, with the advances in satellite communication systems and their increasing importance, wideband antennas are in great demand for both military and commercial applications. Most of the communication systems need a wideband antenna that operates on multi-octave frequencies. In patch antenna, diverse techniques played a vital role in enhancing the antenna parameters such as gain or bandwidth. A new design concept of a compact rectangular dual patch antenna has been developed for both high gain and wider bandwidth. In this work, a compact rectangular dual patch antenna is proposed as a wideband antenna for multiple satellite communication applications such as Global Positioning System, Global Navigation Satellite System, Indian Regional Navigation Satellite System, and S-Band Satellite Communication. The designed rectangular dual patch antenna is simulated and fabricated. Based on the performance, the fabricated antenna is compared with the simulated results in terms of VSWR, gain, axial ratio, and 3 dB beam width. Increased gain and wider bandwidth have been achieved with the developed rectangular patches and their energy distributed on the surface of the dual patches simultaneously. Finally, the proposed rectangular dual patch antenna shows improved performance for the multiple satellite communication applications.

     

ACS-Fed e-Shaped Dual Band Uniplanar Printed Antenna for Modern Wireless Communication Applications

A printed small size (12×16.5 mm) ACS-fed e-shaped uniplanar antenna is proposed for dual band applications. The multiband operating characteristics have been achieved by integrating e-shaped radiating strips to the 50ΩACSfeed line. Two simultaneously operating wide bands have been generated by using optimized radiating branch strips for the multiband applications. For obtaining size reduction and wider impedance bandwidth, e-shaped meandered elements are chosen in the design. The proposed design features the bandwidth (VSWR < 2, reflection coefficient below–10 dB) of 100 MHz in 2.4–2.5 GHz, and 2100MHzin 4.0–6.1 GHz. The developed multiband antenna can be useful for several wireless communication applications, such as 2.4 GHz Bluetooth/RFID,WLAN(2.4/5.2/5.8 GHz), WiMAX (5.5 GHz), US public safety band (4.9 GHz), ISM band, radio frequency energy harvesting and internet of things (IoT) applications.     

A Pentagonal Shaped Microstrip Planar Antenna with Defected Ground Structure for Ultrawideband Applications

A new compact pentagonal microstrip patch antenna with slotted ground plane structure, developed for use in ultrawideband applications, is studied in this article. The proposed antenna is mainly constituted by a pentagonal shaped patch antenna, a defected ground plane structure, two stubs, and four slots to improve the bandwidth. The designed antenna has an overall dimension of 30?×?17.59?×?1.6 mm³, for WIMAX/WLAN/WiFi/HIPERLAN-2 /Bluetooth/LTE/5G applications with a very large bandwidth starting from 2.66 to 10.82 GHz (S₁₁?<???6 dB). A parametric study of the ground plane structure was carried out to find the final and the optimal UWB antenna, and to confirm that the antenna has good performance and broader bandwidth. The proposed antenna prototype has been fabricated. The measured results indicate that the antenna has a good impedance matching. The antenna has an electrically small dimension with a good gain, a notable efficiency, and a wide impedance bandwidth, which makes this antenna an excellent candidate for ultrawideband wireless communication, microwave imaging, radar applications, and the major part of the mobile phone frequencies as well.

     

Compact Planar Monopole Antenna with Dual Band Notched Characteristics Using T-Shaped Stub and Rectangular Mushroom Type Electromagnetic Band Gap Structure for UWB and Bluetooth Applications

In this paper, an ultra-wideband (UWB) antenna with dual band-notched characteristics is proposed. The proposed antenna also covers ISM (Industrial, Scientific, and Medical)/Bluetooth band. The antenna consists of a microstrip fed truncated U-shaped patch, T-shaped stub, rectangular mushroom type electromagnetic band gap structures (EBG), and partial ground plane. To mitigate the problem of interference due to standard narrow bands (like wireless interoperability microwave access (WiMAX) and wireless local area network (WLAN)) lie in the range of UWB, dual band notched characteristics is introduced. The WiMAX and WLAN band notched characteristics are realized by introducing a T-shaped stub and rectangular mushroom type EBG structures, respectively. The proposed antenna is printed on a 1.6 mm thick FR4 substrate with relative permittivity \((\upvarepsilon _{\mathrm{r}})\) 4.4 and the size of actual antenna is \(36 \times 40\hbox { mm}^{2}\) . The measured results shows that the proposed antenna attains a wide impedance bandwidth \((\hbox {VSWR} \le 2)\) from 2.35 to 11.6 GHz with dual band notched characteristics from 3.29 to 3.9 GHz and 5.1 to 5.85 GHz with stable radiation patterns. The time domain behaviors of the proposed antenna is also analyzed for pulse handling capability.     

一种应用于卫星通信地面站的新型单臂螺旋天线及其阵列的研究

研究了一种应用于卫星通信地面站的新型单臂平面螺旋天线,该天线采用圆柱螺旋激励同轴线馈电,可以形成倾斜的波束,通过改变圆柱螺旋的参数可以调整其输入阻抗以达到阻抗匹配的目的.用矩量法求解了天线的电流分布和三维辐射方向图以及增益轴比等参数,计算结果与参考文献很吻合.为了增强天线的方向性系数和增益,以四元天线阵为例,研究了这种天线组成的天线阵的辐射特性,给出了天线阵的三维辐射方向图.计算结果表明,该天线组成的天线阵同样具有倾斜的波束指向,各天线单元的输入阻抗为接近50 Ω的纯电阻,增益比单个天线单元提高6.3 dB.     

A Dual Polarized Triple Band Stacked Elliptical Microstrip Patch Antenna for WLAN Applications

In this paper, a single coaxial feed dual polarized triple band stacked microstrip patch antenna for wireless applications is presented. The proposed stacked antenna has two resonating elements with lower layer consisting of a truncated corner square patch and upper layer with an elliptical patch. Both the layers of proposed antenna are printed on RT Duroid^® 5880 substrate (having ?_r?=?2.2). The antenna shows triple band resonance at 4.2, 4.8 and 5.8 GHz with circular polarization behaviour at the first two resonances and linear polarization characteristic in the third resonance respectively. The typical realized gain of proposed antenna is around 7 dB in all three resonating bands.     

A Miniaturized Printed Antenna with Extended Circular Patch and Partial Ground Plane for UWB Applications

Wireless Personal Communications - A miniaturized printed antenna with extended circular patch and partial ground plane for ultra-wideband applications is designed and investigated. The overall...     

A Metamaterial Inspired ZOR Antenna Using IDC and Spiral Inductor with Partial Ground Plane for WLAN Application

Wireless Personal Communications - In this article, an open-ended metamaterial antenna structure is designed for WLAN application. The antenna comprises of an interdigital capacitor (IDC) and...     

Hybrid Planar Inverted‐F Antenna with a T‐Shaped Slot on the Ground Plane

In this letter, a novel hybrid planar inverted‐F antenna (PIFA) with a T‐shaped slot on the ground plane is proposed. The loop structure formed by the feed line and shorting pin can be operated as a series and shunt inductance for the PIFA and the T‐shaped slot antenna, respectively. The PIFA operates at a frequency of 1.75 GHz, while the T‐shaped slot on the ground plane operates at 2.4 GHz by the same voltage feeding source. The height of the PIFA is 6.5 mm, and the size of an upper patch is designed to be 30 mm…16 mm. The measured relative impedance bandwidth of the PIFA and the T‐shaped slot are about 12% and 21%, respectively. In addition, good antenna performance was achieved.     

Analysis of the Effect of Ground Plane Size on the Performance of a Probe-fed Cavity Resonator Microstrip Antenna

In this paper, a probe-fed rectangular microstrip patch antenna with partially reflective superstrate at terahertz frequency (600 GHz) has been analyzed and simulated. The analysis of the partially reflective surface shows the highly reflective property of the surface over the wideband of the frequencies. The analysis of a specific configuration (rectangular patch) of partially reflective surface predicts the directivity of antenna to be the order of 24 dBi and subsequently it has been validated with the simulation. The proposed antenna has been simulated by using commercially available CST Microwave Studio simulator based on finite integral technique. Next to this, the application scenario of this kind of the antenna in the terahertz regime of the electromagnetic spectrum has been discussed and it has been obtained that this antenna is capable to establish 9 m long communication link.     

Meander and Koch Hybrid Fractal Curve Based Dual Hexagonal Radiating Patch Antenna for Quad Band Wireless Applications

Wireless Personal Communications - A unique dual hexagonal-shaped radiating patch design with hybrid fractal curves (Meander and Koch) is presented for quad-band wireless applications. Initially,...     

Design and Analysis of MIMO Antenna with High Isolation and Dual Notched Band Characteristics for Wireless Applications

A very compact Superwideband multiple-input–multiple-output antenna with dual notched band characteristics is presented. Superwideband characteristics is obtained by means of radiating patch and high isolation between two input ports are obtained by using T-shaped stub in ground plane. Two rejection bands (wireless interoperability for microwave access (WiMAX)/C-band and wireless local area network) are obtained by etching two elliptical slots on radiating patch. Antenna offers large measured useable bandwidth of 2.60–20.04 GHz. Diversity performance is studied in terms of envelope correlation coefficient, diversity gain and total active reflection coefficient. Antenna also offers desirable radiation pattern, gain and radiation efficiency which makes proposed antenna quite suitable for different wireless applications.

     

超宽带低背腔车载探地雷达收发天线的研究

本文研制了一种超宽带车载探地雷达收发天线系统,采用半椭圆形状的偶极子天线形式和电阻加载的方法展宽了天线的工作带宽,使天线末端的反射明显减小.分析了背腔高度对天线电性能的影响,在保证天线电性能的前提下,采用的背腔高度仅为22mm.设计并制作了一套天线样机,并安装在探测车上,在电波暗室中对天线的电性能进行了测试,测试结果与仿真结果吻合良好,这表明该超宽带收发天线可以满足车载探地雷达系统的需求.     

一种双陷波超宽带单极子天线的设计

提出了一种新型双陷波特性的超宽带单极子天线。通过在介质基板上添加锥形辐射贴片,天线可以覆盖超宽带通信频段。在辐射贴片上引入上、下两个锥形缝隙结构,可以实现3.5 GHz、5.5 GHz的双陷波特性。天线实测模型电压驻波比＜2的阻抗带宽是2.56~10.61 GHz,其中3.18~3.76 GHz和4.4~5.75 GHz具有陷波特性。测试表明,天线在工作频带内具有全向辐射特性。