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1.
    
In this article, a geometrically simple, microstrip line‐fed planar monopole structure with slanting edge ground plane is designed to realize the dual‐band dual‐polarized operation. The proposed antenna consists of a rotated U‐shaped patch and an electromagnetically coupled L‐shaped parasitic radiating element. Owing to the combination of microstrip line‐fed radiating patch and a slanting‐edge rectangular ground plane on the opposite side of the substrate, the proposed dual‐band antenna can generate broad axial ratio bandwidth (ARBW) in the upper frequency band. The overall dimension of the prototype is only 32 × 32 × 1.6 mm3. The measured results validate that the proposed antenna has two operational frequency bands, 29.84% (1.54‐2.08 GHz) for linearly polarized radiation and 71.85% (3.96‐8.4 GHz) for circularly polarized radiation. Measured result shows that 3‐dB ARBW of the proposed antenna is 73.54% (3.80‐8.22 GHz) in the higher frequency band. It shows that the higher frequency band exhibits a left‐hand circularly polarized radiation in the boresight direction.  相似文献   

2.
    
A compact widebeam circularly polarized antenna with wide impedance and axial ratio (AR) bandwidths is proposed in this study. The antenna is composed of a pair of crossed dipoles, four sequentially rotated parasitic elements, a slotted ground plane with four vertical plates, and four inverted L‐shaped structures. A prototype is fabricated and measured. An impedance bandwidth (S11 < ?10 dB) of 102.4% and a 3‐dB AR bandwidth of 83.5% are measured. And half‐power beamwidth is more than 120° over the whole operating band. Radiation patterns are symmetrical and identical in both principal planes. The compact size of antenna is 0.42λ0 × 0.42λ0 × 0.16λ0.  相似文献   

3.
A wide‐beam circularly polarized (CP) cross‐dipole antenna for GNSS applications is proposed in this article. This cross‐dipole antenna is fed by a coaxial cable, on which the slots is added to optimize the impedance matching. These two pairs of dipole arms are designed with different lengths to obtain the circularly polarized radiation. Enhanced wide‐beam CP radiation characteristics can be achieved by curving the dipole arms and adjusting the distance between the arms and the metallic ground plane. The study of proposed antenna performance with different geometric parameters has been conducted. The final antenna exhibits a good impedance bandwidth (IBW) of ～13.1% (1.50‐1.71 GHz), and the 3‐dB axial‐ratio bandwidth is over 7% (1.52‐1.64 GHz). Broad pattern coverage of more than 140°, pure CP radiation at all designed bands and a wide 3 dB axial‐ratio beamwidth (ARBW) of nearly 150° makes this antenna an excellent candidate for satellite communications and navigation systems.  相似文献   

4.
    
A low profile circularly polarized (CP) antenna based on printed monopole and sequential rotation feed network is presented. As the monopole placed on the edge of the limited floor produces an axial radiation, CP radiation will be obtained when the sequential rotation technique is introduced to enclose the 6 monopoles into a hexagon. By folding the top of the monopole elements to the center, the profile of the antenna is reduced greatly. Measurement results show that the proposed antenna has a good CP performance and a small size. The antenna operates at 1.575 GHz with profile of 7 mm and 3 dB beamwidth of 140°.  相似文献   

5.
    
In this article, a circularly polarized coupled slot 1 × 4 stacked patch antenna array with enhanced bandwidth is proposed for S‐band applications. Initially, a patch antenna radiating at 2.79 GHz is designed and maximum energy from feedline to patch element is coupled using two rectangular slots. Whereas, a parallel feedline structure is designed to provide polarization flexibility by creating 0, 90 , and 180o phase differences. Then, a truncated patch element is vertically stacked in the design to achieve broader bandwidth of 600 MHz over frequency range from 2.4 to 3.0 GHz. Finally, a coupled slot 1 × 4 array stacked antenna array having feedline line structure to provide 90o phase difference for circular polarization is designed and fabricated for measurements. It is observed that the final design achieved target specification having impedance matching (|S11 | (dB) < ?10 dB over 2.4 to 3.0 GHz, broad band circular polarization, and 11.5 dBic total gain. Overall, a good agreement between simulated and measurement results is observed.  相似文献   

6.
    
This study investigates the use of a polarization rotation reflective surface (PRRS) to construct a wideband, wide‐beam, low‐profile circularly polarized (CP) patch antenna. The device is composed of a feeding monopole antenna and a novel PRRS‐based dual‐patch artificial magnetic conductor (AMC) cell structure. The PRRS has two polarization rotation (PR) frequency points, generated by properly adjusting the width between square and L‐shaped metallic patches. A large PR band of 35.5% (5.1‐7.3 GHz) was achieved by combining two adjacent PR frequency points. The PRRS‐based patch antenna impedance bandwidth was measured to be 28.6% (5.1‐6.35 GHz), with a 3 dB axial ratio (AR) bandwidth of 21.8% (4.8‐6.4 GHz) and a profile of 0.045λ0. Additionally, the proposed antenna exhibited the largest AR beamwidth (to our knowledge) of 175° and 128° in the xoz and yoz planes, respectively. It also produced a high broadside gain of 6.7 dBic within the operational bandwidth.  相似文献   

7.
    
In this article, a compact single fed hexa‐band circularly polarized (CP) monopole antenna using split ring resonators (SRRs) on the partial ground plane is designed and experimentally investigated. The loaded SRR elements generate multiple circularly polarized bands along with a reduction in antenna size. The multiband can be controlled by changing the configuration of SRRs and their position on the ground plane without altering the monopole radiator. To illustrate the CP mechanism and multiband operation of the proposed configuration, the surface current density has been studied. The antenna is fabricated on RT Duroid 5880 substrate of permittivity 2.2 with a total size of 47 × 40 × 1.57 mm3. Compared with the existing antenna designs, the proposed structure is compact and demonstrates improved multiband performance with circular polarization.  相似文献   

8.
    
In this letter, we present a circular polarization antenna array using the novel slot‐coupling feeding technique. This antenna includes eight elements which are installed in line, each array element is fed by means of two microstrip lines with equal amplitude and phase rotation of 90°. The feeding microstrip lines are coupled to a square patch through a square‐ring slot realized in the feeding network ground plane. With the presence of the slots, this antenna array is able to cover the range of frequency of 3 GHz to 4 GHz. The size of the proposed antenna array is 7λ × 1.8λ × 0.4λ. The measured gain is 15.2 dBi and the bandwidth of S11< ?10 dB is 1 GHz (3–4 GHz, 28%). The antenna array is suited for the WiMAX applications. With the use of slot‐coupling feeding technique, the measured bandwidth for axial ratio < 3 dB is about 24% in the WiMAX frequency band (3.3–3.8GHz). The measured HPBW of the y–z planes is larger than 62°. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:567–574, 2016.  相似文献   

9.
    
This paper presents a new approach to design dual‐band antenna with dual‐sense circularly polarized (CP) operation. A principle for CP radiation is the use of two orthogonal dipoles and properly choosing their lengths can produce either right‐hand CP (RHCP) or left‐hand CP (LHCP) operation. In the proposed structure, the lower frequency band at 2.4 GHz is designed with RHCP radiation and LHCP is the operating mode of the higher band at 3.5 GHz. For verification, an antenna prototype is fabricated and measured. Measured data indicate that good performances over the RHCP and LHCP bands can be obtained with usable bandwidths of 2.9% (2.36‐2.43 GHz) and 1.7% (3.48‐3.54 GHz). Along with this, it also observes good unidirectional radiation patterns and the measured broadside gains are around 7.7 and 7.4 dBic across these frequency ranges.  相似文献   

10.
    
A wideband circularly polarized printed antenna is proposed and fabricated, which employs monofilar spiral stubs and a slit in the asymmetrical ground plane which are fed by an inverted L‐shaped microstrip feedline. The CP operation is realized by embedding an inverted‐L shaped strip and modified ground plane and can be markedly improved by loading monofilar spiral stubs asymmetrically connected at the edge of the ground plane. After optimization, the measured results of the finally structure demonstrate that a 10‐dB bandwidth of 67.6% from 4.6 to 9.3 GHz and a 3‐dB axial‐ratio bandwidth (ARBW) for circular polarization (CP) of 60.1% from 5 to 9.3 GHz could be achieved which could completely cover the WLAN (5.725‐5.85 GHz) band. Therefore, the proposed antenna is suitable for circular polarization applications in C band. To explain the mechanism of broadband circular polarization operation, the analysis of magnetic fields distributions and a parametric study of the design are given. Compared to other recent works, a simpler structure, wider axial ratio and impedance bandwidths and a more compact size are the key features of the proposed antenna.  相似文献   

11.
    
In this article, multiband monopole antenna has been designed for the applications of wireless communication systems. The antenna is composed of I‐shaped strips which are placed in such a way that the each of the resonating strips produced distinct frequency bands. The optimum dimension of the proposed antenna is printed on dielectric substrates of FR4 epoxy having dimensions of 0.3λ0 × 0.21λ0 × 0.009λ0. The antenna has been fabricated and measured for evidence. The measured results are verified with simulated results. The comparison of simulated and measured S11 parameter, radiation pattern, peak gains, and circular polarization are described in the section of experimental results. The measured result shows that the antenna may cover the frequency band of Digital Cellular System, Personal Communications Service, Long Term Evolution‐4G, Bluetooth, Worldwide Interoperability Microwave Access, Wireless Local Area Network, 802.11j (WLAN‐Public Safety), and X‐band (Satellite Communication‐downlink).  相似文献   

12.
    
This letter presents the design of a broadband microstrip CP antenna using single‐fed technique. The feeding network is integrated within the coupling feed patch to simplify the structure. The proposed antenna is designed for Global Navigation satellite System (GNSS) operating at 1575.42 ± 10.23 MHz (GPS: L1 band), 1559～1592 MHz (Galileo: E2‐L1‐E1 band), 1602 ± 5.625 MHz (GLONASS: L1 band) and 1559.052～1591.788 MHz & 1610～1626.5 MHz (BeiDou Navigation Satellite System B1 and L band). Another advantage of this antenna is the much wider bandwidth in both VSWR and 3 dB axial‐ratio compared with traditional single‐fed CP antennas. Details of design, simulated and experimental results of this CP antenna are presented and discussed. The measured results confirm the validity of this design which meet the requirement of GNSS applications.  相似文献   

13.
    
This paper demonstrates the design procedure of a 4 × 8 phased array antenna. Initially, a unit element in multilayer topology with orthogonal slots in the ground plane to couple electromagnetic energy is designed. Then, a stacked patch with truncated edges is placed on the top thick substrate layer to enhance the bandwidth to 600 MHz. This multilayered stacked patch unit element is then used to design a 1 × 4 and 4 × 8 slot coupled stacked patch array. On the bottom side, a novel feedline structure is designed to provide a 90 o phase difference at the antenna feed for the circular polarization. The phase difference is achieved in the feedline structure using a quarter wavelength ( λg/4 ) difference in the lengths. After the numerical validation, both 1 × 4 and 4 × 8 stacked patch antenna arrays are fabricated to validate the simulations. The final 4 × 8 array achieved the target specification of an active reflection of less than ?10 dB over 2.4 to 3.0 GHz, axial ratio of less than 3 dB, and stable radiation pattern over the complete band. In addition, beam scanning characteristics of the proposed stacked patch antenna arrays are also verified. The prototype resulted a peak gain of 19.5 dB at 2.7 GHz, 3‐dB beamwidth around 12 o in the xz‐plane, and scanning range of 90 o . Overall, good agreement between measured and simulated results showed that the proposed designed array capable of providing 600 MHz is an excellent candidate for the radar communication, small commercial drones, and synthetic aperture radar applications.  相似文献   

14.
    
In this article a novel wide‐band artificial magnetic conductor (AMC) based wideband directional antenna is presented for ultra‐wideband (UWB) applications. The proposed novel cross‐slot AMC (CSAMC) achieves wide ±90° reflection phase bandwidth of 4.07 GHz (44.69%) and is used as a reflector. The overall antenna structure is designed with 4 × 4 CSAMC unit cell array and has very compact size of (0.584λ0 × 0.584λ0). The proposed structure improves the radiation properties and exhibits 91.5% (3.13‐8.41 GHz) impedance bandwidth (VSWR ≤2). Additionally, it results in significant improvement in gain and front to back ratio. The proposed antenna is fabricated and its measured performance is in good agreement with simulation results.  相似文献   

15.
    
A miniaturized, loop resonators (LRs)‐loaded, circularly polarized (CP) multi‐dipole antenna with wide axial‐ratio (AR) beamwidth is proposed and demonstrated in this article. The radiator of this CP antenna consists of two pairs of parallel dipoles loaded with four LRs at their corners. By increasing the length of the LR, or decreasing the coupling space between the dipole and the LR, the effective length of the dipole can be lengthened significantly and thus the working frequency can be reduced without increasing the whole aperture size. As a result, a miniaturized radiator structure is completed. A feeding network consisting of a T‐shaped coupling feeding structure and four coplanar striplines having different lengths are specially designed to feed these dipoles with approximately the same magnitude and 90° phase quadrature. What is more, a cavity reflector is employed to achieve a unidirectional radiation with wide axial‐ratio beamwidth. The radiator of the proposed CP antenna has a small aperture size of only 0.34λ0 × 0.34λ0, where λ0 is the free space wavelength at the working frequency. Measured results are in a good agreement with the corresponding simulated counterparts. Especially, the experimental results show that the antenna has achieved a wide AR beamwidth of 182° and 174° at the center frequency in the xoz and yoz planes, respectively.  相似文献   

16.
    
In this work, a wideband linear‐to‐circular polarization converter is proposed based on a bi‐layer band‐pass frequency selective surface (FSS), whose unit cell consists of two layers of identical patterned metal films mounted on the two sides of a homogeneous dielectric layer, and the geometric pattern of each metal film is a square loop aperture surrounding a concentric square corner‐truncated patch. Both measured and simulated results show that the polarization converter can realize linear‐to‐circular polarization conversion in the frequency range from 6.87 to 10.07 GHz, which corresponds to a fractional bandwidth of 37.8%; moreover, its response is almost independent of the polarization and incidence angle of the incoming wave. Compared with published designs, the proposed polarization converter has a simpler geometry but a wider bandwidth, higher transmittance and better stability, it may possess potential applications in the design of CP antennas.  相似文献   

17.
论文提出了一种新型宽带圆极化天线,成本低廉,结构简单,性能优异.此天线基板采用普通FR4板材,其辐射体由方形地、钩形分枝及倒L形分枝三部分组成,并由50Ω微带阻抗传输线进行馈电.天线尺寸为55×55mm2,工作在1.75GHz～2.9GHz.频段.天线的10dB回波损耗相对带宽和3dB轴比(AR)相对带宽分别为49％(1.75GHz～2.9GHz)和50％(1.8GHz～3GHz),其良好的圆极化和阻抗性能可以在相关的无线通信系统中得到很好地应用.  相似文献   

18.
    
A single‐layer circularly polarized reflectarray using rectangle‐shaped elements in X‐band is presented in this article. The designed element is analyzed and optimized with parametrical studies to obtain good performance at the operating frequency. The phase shifts can be controlled by varying the dimensions in two orthogonal directions of the element for circular polarization. A reflectarray antenna with 27 × 27 elements has been designed, manufactured and measured. The measured results show that the proposed reflectarray antenna provides a 1‐dB gain bandwidth of 18% and a 3‐dB axial ratio of 13%. The measured peak gain at 10 GHz is 26.1 dBi, which corresponds to the high aperture efficiency of 40.3%.  相似文献   

19.
    
A dual‐band single‐layer circularly polarized reflectarray composed by elements with variable rotation angles is presented in this article. Orthogonal dipole elements etched on the substrate are designed to operate at 10 and 13.5 GHz, respectively. By introduction of element rotation technique, the proposed reflectarray has a good isolation between the two operating bands and obtains excellent performance of circular polarization compared with the conventional design. All the simulated and measured results demonstrate the advantages of the proposed reflectarray. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:39–47, 2015.  相似文献   

20.
    
A simple structure of broadband circularly polarized slot antenna based on coplanar waveguide (CPW) feeding is proposed in this article. To obtain circular polarization with a single feed, a transition from microstrip to CPW is designed to excite the even and odd modes of the CPW simultaneously. By adjusting the relative position and dimensions of the two circular patches introduced at the end of microstrip line and CPW, a 90° phase difference between two modes can be produced. When the two modes are coupled into the wide slot antenna, broadband circular polarization operation can be realized. The 10‐dB reflection coefficient bandwidth of the proposed antenna is 88.2% (2.49‐6.42 GHz) and 3‐dB AR bandwidth attains 50% (2.72‐4.49 GHz).  相似文献   

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