On the modeling of metal strip antennas contiguous with the edge ofelectrically thick finite size dielectric substrates

A solution to the problem of radiation by a narrow metal strip antenna contiguous with the edge of a dielectric substrate is presented where the substrate has parameters such that its electrical thickness is appreciable. Such an antenna may be useful at millimeter wavelengths as an integrated phased array element forming a part of a monolithic microwave integrated circuit (MMIC). A suitable geometry for this application is illustrated and an efficient computational procedure developed. Comparisons with experimental results for the input impedance and far-field radiation patterns show excellent agreement. The influence of the dielectric substrate on the performance of an antenna designed to operate at approximately 60 GHz is discussed. Two examples, the first involving the analysis of a coplanar strip transmission line fed antenna and the second involving impedance matching and control of cross-polarized radiation using a folded strip dipole, are given to illustrate practical applications of the analytical method to design problems     

Wideband CPW-Fed Spiral-Shaped Slot Antenna for Wireless Applications

A new compact design of CPW-fed wideband (WB) spiral-shaped slot antenna is proposed. The proposed antenna has a compact size with overall dimensions 37-33 mm and is fabricated on FR4 substrate with dielectric constant ? _r = 4.4 and thickness h = 1.6 mm. With the different length of the spiral-shaped slots, simulated and experimental results of the antenna are suitable for WB operations. The–10 dB bandwidth of the WB antenna from measurement is approximately 115.2% (2.36–8.53 GHz). The proposed antenna provides nearly omni-directional radiation characteristics. The new antenna configuration operates in several different bands: 2.4, 3.5, 5.2, 5.5, and 5.8 GHz covering 2.4/5.2/5.8 GHz WLAN bands and 2.5/3.5/5.5 GHz WiMAX bands. The results for S₁₁, far-field H- and E-plane radiation patterns and gain of the proposed antennas are presented and discussed. The agreement between measured results and full-wave simulation validates the feasible configuration of the proposed antennas.     

Miniature aperture-coupled microstrip antenna of very highpermittivity

A miniature aperture-coupled microstrip antenna of very high permittivity designed at 1.66 GHz is described. Superstrates of appropriate thickness are added on the substrate for gain enhancement. Its size is dramatically reduced and the electrical performance remains almost the same as compared with the conventional microstrip antenna of low dielectric constant. Experimental data for the return loss, radiation pattern and measured antenna gain are presented to validate the design     

A Planar UWB Diversity Antenna

A planar dual-port diversity antenna, operating with broadside and/or conical radiation patterns in H-planes, is presented for ultrawideband (UWB) applications. The proposed antenna consists of a suspended square patch with a thick stem underneath. A broadband differential feeding strip is used to feed the square patch. The measured gain for the broadside mode is 8.4–10.3 dBi from 3.1 GHz to 5.2 GHz (50.6%), and the conical mode 3.2–5.1 dBi from 3.1 GHz to 4.9 GHz (45%). The measured reflection coefficients $(vert S _{11} vert, vert S _{22} vert)$ are less than -10 dB over the frequency ranges and the isolation $vert S _{21} vert $ between the two ports is greater than 13.5 dB. The operation of the differential feeding strip on the antenna is discussed. Both pattern diversity and partial polarization diversity are achieved for this antenna.      

Transverse slot antenna array in the broad wall of a rectangular waveguide partially filled with a dielectric slab

A compact and wide-band transverse slot antenna array in the broad wall of a rectangular waveguide partially filled with an H-plane -dielectric slab is presented in this paper. By partially filling an H-plane dielectric slab in the waveguide, the inter-element spacing between slots is reduced to be about 0.8 free-space wavelengths to avoid grating lobes. In addition, the partially filled material provides extra flexibility to adjust the slot impedance as desired within a relatively wide frequency range. A new feeding network is designed for this antenna array, which can prevent the shift in the pointing angle of the array's main radiation beam with the change of frequency. Experimental data for a 2/spl times/4 antenna array operating at X-band show that stable radiation pattern over a wide frequency range can be obtained. The measured gain is 16.9 dB at 10 GHz and the fluctuation is less than 2 dB over a frequency band of 1.5 GHz. The slot array's 10-dB return loss bandwidth is 13% and the cross-polarization level is better than -25 dB.     

Broadband Microstrip Antenna With Left-Handed Metamaterials

A novel type of microstrip antenna is proposed for compact wideband wireless applications. The antenna is composed of six unit cells of left-handed metamaterial (LHM) and a dipole element. The dipole is directly connected to three of six LHM unit cells, which are arranged in a 2 $times$ 3 antenna array form. In this aspect, the proposed antenna is regarded as LHM loaded dipole antenna. The antenna is matched with a stepped impedance transformer and rectangular slot in the truncated ground plane. The coupled LH resonances and simultaneous excitation of different sections of unit cells and dipole result into broad bandwidth. The proposed antenna has a maximum gain of $-$1 dBi at 2.5 GHz. The measured return loss indicates 63% bandwidth for $vert{rm S}11vert≪-10 {rm dB}$ over the band of 1.3–2.5 GHz. The overall size of LHM loaded antenna is $lambda_{0}/2.87timeslambda_{0}/11.27timeslambda_{0}/315.80$ at the center frequency. The radiation of the electrically small LHM unit cells is also demonstrated by the simulated radiation pattern, which is an important concept for the antenna miniaturization.      

基于3D打印技术的宽带圆形微带天线

该文介绍了一款环形耦合的圆形贴片天线。采用圆形金属贴片作为天线的辐射贴片,通过在介质板上引入两个谐振环,产生两个新的工作谐振频段。通过调节圆形贴片和耦合环之间的高度,进一步拓宽了天线的工作频段。通过3D打印技术对不规则的介质基板进行加工制作,有效解决了传统加工方法加工难度大及生产周期长的问题。测试结果表明,该天线在3.8～5.8 GHz工作频段内,回波损耗小于-10 dB;在5.1 GHz时,天线增益达到8.4 dBi;天线相对带宽为42%,且具有良好的全向辐射特性。天线的测试结果与仿真结果基本吻合。     

叶片形超宽带单极天线

提出了一种超宽带叶片形单极天线,该天线在叶片形薄铜片上开三个孔和用相对介电常数为3.5的单层覆铜介质板作接地板。实验天线的实测结果从1.3GHz到29.7GHz约22∶1的超宽频带上,反射损耗都在-10dB以下。这种天线的频带覆盖了L、C、X、Ku各频段,应用前景十分广阔。     

加载介质透镜的超宽带平面螺旋天线设计

针对乳腺癌检测、成像等医疗领域对天线高增益及宽频带的需求,研究设计了一款加载介质透镜的超宽带平面螺旋天线。该天线采用双臂平面阿基米德螺旋天线作为辐射单元,在辐射臂外围间隔一定距离处加载金属圆环以改善驻波性能,并由指数渐变式微带巴伦作为馈电结构。天线顶部加载介质透镜,底部设置金属圆台形反射背板,实现了调整波束形状和提高天线增益的目的。加装圆柱形天线罩后天线高度约为87.53 mm,直径约为46.50 mm。仿真结果显示,天线在3－12 GHz 工作频带内回波损耗小于-10 dB,辐射方向图呈现良好的定向辐射特性,实测结果与仿真结果基本一致。     

Conformal Antennas on Liquid Crystalline Polymer Based Rigid-Flex Substrates Integrated With the Front-End Module

Recent developments in liquid crystalline polymer (LCP)-based processing technology have shown that highly-integrated, fully-packaged radio-frequency (RF) front-end modules with high-performance can be designed by using the system-on-package (SOP) approach. However, the direct integration of a large antenna element to a small module package still remains an issue. This paper presents a novel conformal antenna structure, which results in a compact integration of the antenna and the module package for 5 GHz WLAN/WiMAX applications. The extension of 5 GHz single-band operation to 2.4/5 GHz dual-band operation is also discussed in this paper. The antenna is an inverse L-shaped monopole printed on a 25-$mu{hbox {m}}$-thick flexible LCP layer, which protrudes from a rigid multilayer organic substrate. The shielding effects of a grounded metal case, which can house the associated module circuitry, are also considered during the design process. The metal case serves as a vertical ground plane for the antenna in addition to protecting the module circuitry from the near-fields of the antenna. The flexible LCP substrate can be bent and folded over the module case, resulting in a compact design and the tight integration of the antenna with the front-end module. The details of the design and the fabrication of the proposed structure as well as the simulation and the measurement data are presented in this paper.      

Compact uniplanar antenna for WLAN applications

A compact dual-band uniplanar antenna for operation in the 2.4/5.2/5.8 GHz WLAN/HIPERLAN2 communication bands is presented. The dual-band antenna is obtained by modifying one of the lateral strips of a slot line, thereby producing two different current paths. The antenna occupies a very small area of 14.5times16.6 mm² including the ground plane on a substrate having dielectric constant 4.4 and thickness 1.6 mm at 2.2 GHz. The antenna resonates with two bands from 2.2 to 2.52 GHz and from 5 to 10 GHz with good matching, good radiation characteristics and moderate gain     

一种应用于WLAN的抗金属四频段平面单极天线设计

用于非金属外壳设备的常规天线与金属外壳设备一起使用,会导致完全不同的回波损耗。因此,提出了一种同时适用于金属外壳和非金属外壳设备的四频段平面单极天线,该天线由一个弯曲接地层、一对寄生贴片和由同轴馈电激发的辐射片组成。提出的天线能够在不同类型接地层影响下,保持其谐振频率一致性,甚至能够连接到金属外壳上。该天线适用于在WLAN 2.4/5.2/5.8 GHz、WiMAX 3.5/5.5 GHz和4.5GHz工作的多种应用。仿真和实际测量结果显示,即便是连接到较大的金属外壳或金属板时,提出天线能够较好地保持回波损耗和增益一致性且符合行业标准。     

Angled Split-Ring Artificial Magnetic Conductor for Gain Enhancement in Microstrip Patch Antenna for Wireless Applications

A multiband rectangular microstrip patch antenna integrated with angled split- ring artificial magnetic conducting (AMC) structure is proposed. In order to achieve high gain, directivity and radiation efficiency, an \(3\times 2\) array of proposed angled split-ring patches which has multiple in-phase reflection phase characteristics at S-band (2–4 GHz) is presented as a reflector. A rectangular microstrip patch antenna integrated with the proposed angled split-ring AMC is fabricated, tested and its parameters are compared with the microstrip patch antenna backed with a flat metal sheet, and microstrip patch antenna integrated with conventional split-ring AMC structure. The presence of high scattered field amplitude between the angled arms lead to improved radiation characteristics and make the antenna more suitable for real-time wireless applications. The antenna attains 2.138 dBi increment in gain and 1.87 dBi increment in directivity when it is backed with the proposed angled split-ring artificial magnetic conducting structure instead of a flat metal sheet. A good pact is obtained between the simulated and the measured results.     

A planar UWB antenna with signal rejection capability in the 4-6 GHz band

The design of a compact planar antenna featuring ultra wideband performance and simultaneous signal rejection in the 4-6 GHz band, assigned for IEEE802.11a and HIPERLAN/2, is presented. The design is demonstrated assuming RT6010LM substrate with a relative dielectric constant of 10.2 and thickness of 0.64 mm. The presented results show that the designed antenna of 27 mm /spl times/ 20 mm dimensions has a bandwidth from 2.7 GHz to more than 10 GHz excluding the rejection band. The antenna features near omnidirectional characteristics and good radiation efficiency.     

Ka-band Dielectric Waveguide Antenna Array for Millimeter Wave Active Imaging System

Ka-band compact dielectric waveguide antenna array for active imaging system is given. Antenna array with WR28 metal waveguide direct feeding is specially designed with small size, high gain, good radiation pattern, easy realization, low insertion loss and low mutual coupling. One practical antenna array for 3-D active imaging system is shown with theoretic analysis and experimental results. The mutual coupling of transmitting and receiving units is less than -30dB, the gain from 26.5GHz to 40GHz is (12-16) dB. The results in this paper provide guidelines for the designing of millimeter wave dielectric waveguide antenna array.     

Long backfire antenna with insular image guide feed for dual frequency operation

A long backfire antenna using an insular image waveguide feed compatible with microwave dielectric integrated circuit technology is presented. The antenna operates as a backfire component from 9.7 to 9.9 GHz and as an endfire antenna from 8.9 to 9.9 GHz, with symmetrical radiation patterns and low crosspolarisation. The important parameters of the antenna are experimentally optimised to give a maximum gain of 20 dB and 17 dB when working as a backfire and endfire antenna, respectively. This type of antenna can find extensive applications at millimetre-wave frequencies.     

A Microstrip Fed Patch Antenna with Two Parasitic Invert L Stubs for Dual-Band WLAN Applications

A novel microstrip fed dual-band design patch antenna with two parasitic invert L stubs for 2.4/5- GHz wireless applications is presented in this paper. Printed on a dielectric substrate of FR4 with relative permittivity of 4.4 and thickness of 1 mm, and fed by a 50Ω microstrip line, the patch antenna with two parasitic invert L stubs is demonstrated to generate three resonant modes to cover 2.4/5.2/5.8- GHz wireless local area network (WLAN) bands with satisfactory radiation characteristics. Experimental and simulated S parameters are presented. Parameters sweep and simulated radiation patterns are demonstrated.     

Design and analysis of single and multi-input multioutput triple-band metamaterial inspired antennas for WiMAX,WLAN, and satellite applications

This work proposes an electrical compact triple-bands antenna founded on a composite left-/right-handed approach. This structure contains a rectangular patch combined with two unit cells based on the metamaterial properties that are used to produce wide electrical lengths in miniature physical sizes. Thus, the presented antenna is designed with a lower resonant frequency and miniature physical dimensions compared to conventional antennas. The suggested antenna has been produced on top of the FR4 substrate having tan δ = 0.022, εr = 4.58, and a size of 28 × 16 × 1.6 mm³. This structure provides three bandwidths of (2.391–2.54 GHz), (3.42–3.56 GHz), and (5.02–11.40 GHz). Additionally, a multi-input multioutput (MIMO) antenna is designed by placing two similar radiating patches in a perpendicular shape. Therefore, this design approach has been used to achieve an important isolation among ports and less than −30 dB at frequency bands. The results of radiation patterns, envelope correlation coefficient, diversity gain, and channel capacity loss are below to 0.06, 10 dB, and 0.4 b/s/Hz respectively, which confirms that the MIMO antenna is compatible with wireless MIMO devices. These antennas have been modeled and experimentally confirmed, and the results have proven that the suggested antennas are useable and can support multi-standard wireless applications.     

Dielectric Resonator Antenna on Silicon Substrate for System On-Chip Applications

This paper presents for the first time the design and performance of a novel integrated dielectric resonator antenna fabricated on a high conducting silicon substrate for system on-chip applications. A differential launcher to excite the ${rm TE}_{01delta}$ mode of the high permittivity cylindrical dielectric resonator was fabricated using the IBM SiGeHP5 process. The proposed antenna integrated on a silicon substrate of conductivity 7.41 S/m has an impedance bandwidth of 2725 MHz at 27.78 GHz, while the achieved gain and radiation efficiency are 1 dBi and 45% respectively. The design parameters were optimized employing Ansoft HFSS simulation software. Very good agreement has been observed between simulation and experimental results. The results demonstrate that integration of dielectric resonator antennas on silicon is viable, leading to the fabrication of high efficient RF circuits, ultra miniaturization of ICs and for the possible integration of active devices.      

Efficiency enhancement of microstrip antenna by elevating radiating edges of patch

A new structure for a microstrip patch antenna fabricated on a highly lossy and thin FR4 substrate is presented. Elevated radiating edges of the metallic patch with notches as inductive loading form the patch antenna. This structure effectively reduces the dielectric loss and enhances the radiation efficiency. The proposed antenna has been designed and tested at 3.1 GHz as an example. It showed increased radiation power levels of more than 3 dB in both E- and H-plane radiation patterns when compared with those of a conventional planar patch antenna, indicating enhanced radiation efficiency.