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Showing papers on "Dipole antenna published in 2012"


Journal ArticleDOI
TL;DR: This work investigates the interaction of circularly polarized (CP) light at an interface composed of a dipole antenna array to create spatially varying abrupt phase discontinuities and designs and experimentally demonstrates an ultrathin phase gradient interface to generate a broadband optical vortex beam based on the above principle.
Abstract: Ultrathin metasurfaces consisting of a monolayer of subwavelength plasmonic resonators are capable of generating local abrupt phase changes and can be used for controlling the wavefront of electromagnetic waves. The phase change occurs for transmitted or reflected wave components whose polarization is orthogonal to that of a linearly polarized (LP) incident wave. As the phase shift relies on the resonant features of the plasmonic structures, it is in general wavelength-dependent. Here, we investigate the interaction of circularly polarized (CP) light at an interface composed of a dipole antenna array to create spatially varying abrupt phase discontinuities. The phase discontinuity is dispersionless, that is, it solely depends on the orientation of dipole antennas, but not their spectral response and the wavelength of incident light. By arranging the antennas in an array with a constant phase gradient along the interface, the phenomenon of broadband anomalous refraction is observed ranging from visible to ...

841 citations


Journal ArticleDOI
TL;DR: A printed two-multiple-input multiple-output (MIMO)-antenna system incorporating a neutralization line for antenna port decoupling for wireless USB-dongle applications is proposed and it was found that the antenna port isolation can be effectively improved by removing only 1.5 mm long inwards from the top edge in the small ground portion.
Abstract: A printed two-multiple-input multiple-output (MIMO)-antenna system incorporating a neutralization line for antenna port decoupling for wireless USB-dongle applications is proposed. The two monopoles are located on the two opposite corners of the system PCB and spaced apart by a small ground portion, which serves as a layout area for antenna feeding network and connectors for the use of standalone antennas as an optional scheme. It was found that by removing only 1.5 mm long inwards from the top edge in the small ground portion and connecting the two antennas therein with a thin printed line, the antenna port isolation can be effectively improved. The neutralization line in this study occupies very little board space, and the design requires no conventional modification to the ground plane for mitigating mutual coupling. The behavior of the neutralization line was rigorously analyzed, and the MIMO characteristics of the proposed antennas was also studied and tested in the reverberation chamber. Details of the constructed prototype are described and discussed in this paper.

363 citations


Journal ArticleDOI
TL;DR: In this article, a high-efficiency 2.45 GHz rectenna with a simple structure and high gain of 8.6 dBi is proposed for the rectenna, which can harvest low input RF power effectively.
Abstract: This letter presents a high-efficiency 2.45-GHz rectenna that can harvest low input RF power effectively. A new antenna with a simple structure and high gain of 8.6 dBi is proposed for the rectenna. The antenna is designed to directly match the rectifying circuit at 2.45 GHz and mismatch it at the second and third harmonics so that the use of bandpass filter between the antenna and rectifying circuit can be eliminated. The rectenna shows a maximum conversion efficiency of 83% with a load resistance of 1400 Ω. Furthermore, the overall conversion efficiency can remain 50% for the low, -17.2 dBm (corresponding power density 0.22 μW/cm2 ) input power level.

326 citations


Patent
Bing Dang1, Duixian Liu1, Loic Marnat1, Atif Shamim1, Cornelia K. Tsang1 
27 Nov 2012
TL;DR: In this paper, a radio frequency integrated circuit (RFIC) chip package is provided having an RFIC chip and an integrated antenna structure, which includes an on-chip antenna having one or more radiator elements formed as part of a back-end-of-line structure.
Abstract: A radio frequency integrated circuit (RFIC) chip package is provided having an RFIC chip and an integrated antenna structure. The integrated antenna structure includes an on-chip antenna having one or more radiator elements formed as part of a back-end-of-line structure of the RFIC chip. The antenna structure further includes a superstrate structure disposed on the back-end-of-line structure of the RFIC chip. The superstrate structure includes at least one substrate layer and a focusing metal element. The focusing metal element has a structure that is complementary to the on-chip radiator elements and which is configured to focus electromagnetic radiation to and from the planar antenna structure. The superstrate structure improves the performance (e.g., antenna gain and bandwidth) of the on-chip antennas for millimeter-wave applications.

271 citations


Journal ArticleDOI
03 Apr 2012
TL;DR: In this paper, stringent requirements imposed on the design of base station antennas for mobile communications are summarized and a new magnetoelectric dipole that is low in profile and robust in structure is presented.
Abstract: In this paper, stringent requirements imposed on the design of base station antennas for mobile communications are summarized. Conventional techniques for implementing base station antennas are reviewed. The complementary antenna concept of combining an electric dipole with a magnetic dipole is reconsidered. Recently, this kind of antenna has been commonly called a “Huygen's source.” The purpose is to develop wideband unidirectional antennas with stable frequency characteristics and low back radiation. Based on this concept, the magnetoelectric dipole was invented by integrating an electric dipole with an -probe fed shorted quarter-wave patch antenna. A number of magnetoelectric dipoles with different radiation patterns and different polarizations have been developed in recent years. An overview of the characteristics of this new class of complementary antennas is presented. Major design challenges are explained. Finally, a new magnetoelectric dipole that is low in profile and robust in structure is presented. The magnetic dipole part of this antenna is realized by a triangular-shaped loop antenna. The antenna is inherently direct current (dc) grounded, which satisfies the requirement for outdoor applications.

253 citations


Journal ArticleDOI
TL;DR: A novel plasmonic antenna geometry - the double resonant antenna (DRA) - that is optimized for second-harmonic generation (SHG) is presented, based on two gaps coupled to each other so that a resonance at the fundamental and at the doubled frequency is obtained.
Abstract: We present a novel plasmonic antenna geometry – the double resonant antenna (DRA) – that is optimized for second-harmonic generation (SHG). This antenna is based on two gaps coupled to each other so that a resonance at the fundamental and at the doubled frequency is obtained. Furthermore, the proximity of the localized hot spots allows for a coupling and spatial overlap between the two field enhancements at both frequencies. Using such a structure, both the generation of the second-harmonic and its re-emission into the far-field are significantly increased when compared with a standard plasmonic dipole antenna. Such DRA are fabricated in aluminium using electron beam lithography and their linear and nonlinear responses are studied experimentally and theoretically.

248 citations


Journal ArticleDOI
TL;DR: The physical basis of the light-matter interaction at the transition from the RF to optical regime is reviewed, the extension of antenna theory as needed for the design of impedance-matched optical antenna-load coupled systems are discussed, and several examples of the state of the art in design strategies are provided and suggest future extensions.
Abstract: The goal of antenna design at optical frequencies is to deliver optical electromagnetic energy to loads in the form of, e.g.,?atoms, molecules or nanostructures, or to enhance the radiative emission from such structures, or both. A true optical antenna would, on a qualitatively new level, control the light?matter interaction on the nanoscale for controlled optical signal transduction, radiative decay engineering, quantum coherent control, and super-resolution microscopy, and provide unprecedented sensitivity in spectroscopy. Resonant metallic structures have successfully been designed to approach these goals. They are called optical antennas in analogy to radiofrequency (RF) antennas due to their capability to collect and control electromagnetic fields at optical frequencies. However, in contrast to the RF, where exact design rules for antennas, waveguides, and antenna?load matching in terms of their impedances are well established, substantial physical differences limit the simple extension of the RF concepts into the optical regime. Key distinctions include, for one, intrinsic material resonances including quantum state excitations (metals, metal oxides, semiconductor homo- and heterostructures) and extrinsic resonances (surface plasmon/phonon polaritons) at optical frequencies. Second, in the absence of discrete inductors, capacitors, and resistors, new design strategies must be developed to impedance match the antenna to the load, ultimately in the form of a vibrational, electronic, or spin excitation on the quantum level. Third, there is as yet a lack of standard performance metrics for characterizing, comparing and quantifying optical antenna performance. Therefore, optical antenna development is currently challenged at all the levels of design, fabrication, and characterization. Here we generalize the ideal antenna?load interaction at optical frequencies, characterized by three main steps: (i) far-field reception of a propagating mode exciting an antenna resonance, (ii) subsequent transformation of that mode into a nanoscale spatial localization, and (iii) near-field coupling via an enhanced local density of states to a quantum load. These three steps define the goal of efficient transformation of incident radiation into a quantum excitation in an impedance-matched fashion. We review the physical basis of the light?matter interaction at the transition from the RF to optical regime, discuss the extension of antenna theory as needed for the design of impedance-matched optical antenna?load coupled systems, and provide several examples of the state of the art in design strategies and suggest future extensions. We furthermore suggest new performance metrics based on the combination of electric vector field, field enhancement and capture cross section measurement to aid in comparison between different antenna designs and optimization of optical antenna performance within the physical parameter space.

228 citations


Journal ArticleDOI
TL;DR: In this paper, an ultrawideband multiple-input-multiple-output (MIMO) antenna that covers the WCDMA (1.92-2.17 GHz), WiMAX (2.3, 2.4 GHz), and UWB (3.1-10.6 GHz) bands for wireless device applications is presented.
Abstract: This letter presents an ultrawideband multiple-input-multiple-output (MIMO) antenna that covers the WCDMA (1.92-2.17 GHz), WiMAX (2.3, 2.5 GHz), WLAN (2.4 GHz), and UWB (3.1-10.6 GHz) bands for wireless device applications. The proposed antenna consists of a printed folded monopole antenna coupled with a parasitic inverted-L element, with an open stub inserted in the antenna to reject the WLAN (5.15-5.85 GHz) band that interferes with the UWB band. These two antennas are symmetrically arranged on a mobile device substrate. The -10-dB bandwidth of the designed antenna is 1.85-11.9 GHz without the WLAN band 5.15-5.85 GHz. S21 and the envelope correlation coefficient are lower than -17.2 dB and 0.18 in the operating bands, respectively. The size of the antenna is 55 ×13.5 × mm2.

185 citations


Journal ArticleDOI
TL;DR: In this paper, a closely packed ultrawideband (UWB) multiple-input multiple-output (MIMO)/diversity antenna (of two elements) with a size of 25 mm by 40 mm is proposed for USB dongle applications.
Abstract: A closely-packed ultrawideband (UWB) multiple- input multiple-output (MIMO)/diversity antenna (of two elements) with a size of 25 mm by 40 mm is proposed for USB dongle applications. Wideband isolation can be achieved through the different patterns and polarizations of the two antenna elements. Moreover, the slot that is formed between the monopole and the ground plane of the half slot antenna is conveniently used to further enhance the isolation at the lower frequencies and to provide an additional resonance at one antenna element in order to increase its bandwidth. The underlying mechanisms of the antenna's wide impedance bandwidth and low mutual coupling are analyzed in detail. Based on the measurement results, the proposed antenna can cover the lower UWB band of 3.1-5.15 GHz, and within the required band, the isolation exceeds 26 dB. The gains and total efficiencies of the two antenna elements are also measured. Furthermore, a chassis mode can be excited when a physical connection is required between the ground planes of the two antenna elements. Without affecting the performance of the half slot element, the monopole can now cover the band of 1.78-3 GHz, apart from the UWB band. The proposed antenna structure is found to provide good MIMO/diversity performance, with very low envelope correlation of less than 0.1 across the UWB band.

178 citations


Journal ArticleDOI
TL;DR: In this paper, a printed diversity monopole antenna is presented for WiFi/WiMAX applications, which comprises two crescent shaped radiators placed symmetrically with respect to a defected ground plane and a neutralization line is connected between them to achieve good impedance matching and low mutual coupling.
Abstract: A novel printed diversity monopole antenna is presented for WiFi/WiMAX applications. The antenna comprises two crescent shaped radiators placed symmetrically with respect to a defected ground plane and a neutralization lines is connected between them to achieve good impedance matching and low mutual coupling. Theoretical and experimental characteristics are illustrated for this antenna, which achieves an impedance bandwidth of 54.5% (over 2.4-4.2 GHz), with a reflection coefficient <;-10 dB and mutual coupling <;-17 dB. An acceptable agreement is obtained for the computed and measured gain, radiation patterns, envelope correlation coefficient, and channel capacity loss. These characteristics demonstrate that the proposed antenna is an attractive candidate for multiple-input multiple-output portable or mobile devices.

177 citations


Journal ArticleDOI
TL;DR: In this article, the design, fabrication, and measurement of a 16 × 16 dual-polarized planar ultrawideband modular antenna (PUMA) array operating over 7-21 GHz (3:1 bandwidth) is presented.
Abstract: The design, fabrication, and measurement of a 16 × 16 dual-polarized planar ultrawideband modular antenna (PUMA) array operating over 7-21 GHz (3:1 bandwidth) are presented. The array is comprised of tightly coupled dipoles printed on a grounded dielectric substrate and are excited by an unbalanced feeding scheme that eliminates external wideband baluns and feed organizers. The array can be assembled modularly, where each low-profile, fully planar, low-cost tile is fabricated using standard multilayer microwave PCB techniques. A unique solderless, modular interconnect mates the array to a dilation fixture that facilitates measurements using standard surface-mount assembly (SMA) connectors and terminations. After presenting the most critical design trends, simulation results of the final array in infinite, infinite × finite, and finite × finite models are compared with measurements. This prototype array exhibits a measured active VSWR <; 2.1 and close to ideal gain at broadside, and VSWR <; 2.8 with low cross-polarization out to θ = 45° in all planes, showing close agreement with simulations.

Journal ArticleDOI
TL;DR: In this paper, a 60 GHz wideband circularly polarized (CP) helical antenna array of 4 × 4 elements is designed and fabricated using low temperature co-fired ceramic (LTCC) technology.
Abstract: A 60-GHz wideband circularly polarized (CP) helical antenna array of 4 × 4 elements is designed and fabricated using low temperature cofired ceramic (LTCC) technology. The flexible via hole distribution is fully utilized to achieve a helical antenna array to obtain good circular polarization performance. Meanwhile, grounded coplanar waveguide (GCPW) to stripline is utilized for probe station measurement. Unlike traditional helical antennas, the proposed helical antenna array is convenient for integrated applications. The fabricated antenna array has dimension of 12 × 10 × 2 mm3. The simulated and measured impedance, axial ratio (AR) and radiation pattern are studied and compared. The proposed antenna array shows a wide measured impedance bandwidth from 52.5 to 65.5 GHz for | S11| <; -10dB, wideband measured AR bandwidth from 54 to 66 GHz for AR <;3 dB, respectively.

Journal ArticleDOI
TL;DR: In this article, a small-size microstrip-fed multi-band planar monopole antenna is presented, which covers the frequency bands 1.3, 1.8, 2.4 and 3.6 GHz.
Abstract: A small-size microstrip-fed multi-band planar monopole antenna is presented. The base of the proposed antenna is a diamond-shaped-patch (DSP) that covers the ultrawideband (UWB) frequency range. To create a multi-band antenna, several narrow strips, acting as resonance paths, can be integrated with the DSP antenna. It is shown that by removing the centre part of the DSP antenna, without distorting the UWB behavior, quarter-wavelength strips can be added to the notched region. This will not affect the dimension of the base antenna. The designed quad-band antenna has a substrate size of 16 × 22 mm2 and covers the frequency bands 1.3, 1.8, 2.4 and 3.1-10.6 GHz which includes GPS, GSM, WLAN and UWB. Dual-, triple- and quad-band antennas are simulated and good results are obtained. The antennas have omnidirectional and stable radiation patterns across all the relevant bands. Moreover, relatively consistent group delays across the UWB frequencies are noticed for the base, dual- and triple-band antennas, and slightly distorted for the quad-band antenna. A prototype of the quad-band antenna is fabricated and measured results are compared with simulated results.

Journal ArticleDOI
TL;DR: In this article, a fixed-frequency electronically-steerable one-dimensional (1-D) leaky-wave antenna is presented, which is based on a parallel-plate waveguide loaded with a planar partially reflective surface and a tunable high impedance surface.
Abstract: A novel fixed-frequency electronically-steerable one-dimensional (1-D) leaky-wave antenna is presented. The antenna is based on a parallel-plate waveguide loaded with a planar partially reflective surface and a tunable high impedance surface (HIS), which creates a 1-D Fabry-Perot leaky-waveguide. The tunable HIS consists of printed patches loaded with varactor diodes that allow the electronic tuning of the cavity resonance condition. Using a simple Transverse Equivalent Network, it is theoretically shown how the variation of the varactors' junction capacitance allows the scanning of the antenna pointing angle from broadside towards the endfire direction at a fixed frequency. Experimental results of an antenna prototype operating at 5.6 GHz are reported, demonstrating that the new reconfigurable leaky-wave antenna can provide electronic beam scanning in an angular range from 9 $^{\circ}$ to 30 $^{\circ}$

Journal ArticleDOI
TL;DR: In this paper, a compact ultrawideband (UWB) antenna printed on a 50.8-μm Kapton polyimide substrate is presented, which is fed by a linearly tapered coplanar waveguide that provides smooth transitional impedance for improved matching.
Abstract: In this letter, we present a compact ultrawideband (UWB) antenna printed on a 50.8-μm Kapton polyimide substrate. The antenna is fed by a linearly tapered coplanar waveguide (CPW) that provides smooth transitional impedance for improved matching. The proposed design is tuned to cover the 2.2-14.3-GHz frequency range that encompasses both the 2.45-GHz Industrial, Scientific, Medical (ISM) band and the standard 3.1-10.6-GHz UWB band. Furthermore, the antenna is compared to a conventional CPW-fed antenna to demonstrate the significance of the proposed design. A parametric study is first performed on the feed of the proposed design to achieve the desired impedance matching. Next, a prototype is fabricated; measurement results show good agreement with the simulated model. Moreover, the antenna demonstrates a very low susceptibility to performance degradation due to bending effects in terms of impedance matching and far-field radiation patterns, which makes it suitable for integration within modern flexible electronic devices.

Patent
17 Jul 2012
TL;DR: An electromagnetic-radiation power-supply mechanism includes a microwave power introduction port provided on the side of the coaxial waveguide and a power supply antenna for radiating the electromagnetic wave power into the waveguide as mentioned in this paper.
Abstract: An electromagnetic-radiation power-supply mechanism includes a microwave power introduction port provided on the side of the coaxial waveguide, a power line being connected to the microwave power introduction port; and a power supply antenna for radiating the electromagnetic wave power into the waveguide, the power supply antenna being connected to the power line. The power supply antenna includes an antenna body having a first pole connected to the power line and a second pole connected to an inner conductor of the waveguide; and a ring-shaped reflection portion extending from opposite sides of the antenna body.

Journal ArticleDOI
TL;DR: In this article, a planar antenna design incorporating a high impedance surface (HIS) is presented, which is composed by a periodic array of subwavelength dogbone-shaped conductors printed on top of a thin dielectric substrate and backed by a metallic ground plane.
Abstract: A fully planar antenna design incorporating a high impedance surface (HIS) is presented. The HIS is composed by a periodic array of subwavelength dogbone-shaped conductors printed on top of a thin dielectric substrate and backed by a metallic ground plane. First, the characteristics of a dipole over PEC or PMC layers, a dielectric slab, and the HIS are compared and studied in detail, highlighting the advantages provided by the use of the HIS. Then, the design of a low profile folded dipole antenna working at 5.5 GHz on top of the HIS is described. The surface provides close to 6% antenna impedance bandwidth and increased gain up to 7 dBi, while shielding the lower half space from radiation. The antenna structure comprises three metal layers without any vias between them, and its overall thickness is 0.059λ0. The dipole is fed by a balanced twin lead line through a balun transformer integrated in the same antenna layer. A prototype has been built and measurements confirming simulation results are provided.

Journal ArticleDOI
TL;DR: In this paper, a low-profile magneto-electric dipole antenna composed of a horizontal planar dipole and a vertically oriented folded shorted patch antenna is presented for SWR ≤ 1.5 from 1.88 to 3.3 GHz.
Abstract: A new low-profile magneto-electric dipole antenna composed of a horizontal planar dipole and a vertically oriented folded shorted patch antenna is presented. The antenna is simply excited by a coaxial feed without the need of an additional balun. A rectangular cavity-shaped reflector is introduced for enhancing the stability in radiation pattern over the operating frequencies. A parametric study is performed for providing practical design guidelines. A prototype with a thickness of 0.173λ was designed, fabricated and measured. Results show that an impedance bandwidth of 54.8% for SWR ≤ 1.5 from 1.88 to 3.3 GHz was achieved. Stable radiation pattern with low cross polarization, low back radiation and an antenna gain of 8.6 ± 0.8 dBi was found over the operating frequencies. In addition, the antenna is d.c. grounded, which satisfies the requirement of many outdoor antennas.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the possibility of using the mantle cloaking approach to reduce mutual blockage effects between two electrically close antennas and showed that by covering the two antennas with properly patterned metasurfaces printed on realistic substrates, it is possible to make each antenna invisible to the other and preserve their individual operation as if they were isolated.
Abstract: In this letter, we investigate the possibility of using the mantle cloaking approach to reduce mutual blockage effects between two electrically close antennas. In particular, we consider the case of two dipoles resonating at different, close frequencies and separated by an electrically short distance ( λ0 /10 at 3 GHz). We show that by covering the two antennas with properly patterned metasurfaces printed on realistic substrates, it is possible to make each antenna invisible to the other and preserve their individual operation as if they were isolated. This new cloaking application is confirmed by realistic full-wave numerical simulations.

Journal ArticleDOI
TL;DR: Measurements performed on the antenna after bending and integration into clothing indicate high robustness against deformation and low influence of the human body on antenna performance, making the design well-suited for on-body use.
Abstract: A novel wearable substrate integrated waveguide antenna fabricated entirely from textile materials is presented. The cavity-backed slot antenna operates in the 2.45 GHz industrial, scientific and medical band, for short range communication between rescue workers. A prototype of the antenna was fabricated and tested: good performance was obtained in terms of input matching and radiation pattern. Moreover, measurements performed on the antenna after bending and integration into clothing indicate high robustness against deformation and low influence of the human body on antenna performance, making the design well-suited for on-body use.

Journal ArticleDOI
TL;DR: In this article, a novel ultrawideband (UWB) microstrip monopole antenna with reconfigurable multiband function is presented, which is achieved by using GaAs field effect transistor (FET) switches to connect multiple stubs of different lengths to the main feed line of the monopole.
Abstract: A novel ultrawideband (UWB) microstrip monopole antenna with reconfigurable multiband function is presented. Reconfigurability is achieved by using GaAs field effect transistor (FET) switches to connect multiple stubs of different lengths to the main feed line of the monopole. The antenna is compact and flexible in terms of the availability of different reconfiguration bands and, most importantly, the simple biasing of the GaAs FET switches will not have a severe effect on the antenna performance. Using GaAs FET switches did not degrade the antenna radiation patterns due to the simple biasing technique and the few external biasing components needed, besides these switches did not degrade the antenna gain and efficiency due to their low insertion loss and low on resistance. When the antenna was reconfigured from UWB to work into multiple frequency bands, the total peak gain improved by 20% compared to the UWB case. In addition, the total efficiency of the antenna has not been significantly reduced in any reconfigured band, whereas the out-of-band total efficiency is hugely reduced, which highlights the filtering role of the reconfiguration process. The total dc power consumption of the antenna switches is still very low (<; 33 μW), and this will lead to simple integration of the antenna in some portable communication systems or future cognitive radio front ends.

Patent
30 Aug 2012
TL;DR: In this paper, a radio frequency identification (RFID) chip that receives and modulates a Radio Frequency (RF) signal was provided for use with a RFID chip that received and modulated a RF signal, and a substrate of the device includes a first short dipole antenna structure that backscatters a received RF signal to produce a first radiation pattern having nulls.
Abstract: A device is provided for use with a radio frequency identification (RFID) chip that receives and modulates a radio frequency (RF) signal. A substrate of the device includes a first short dipole antenna structure that backscatters a received RF signal to produce a first radiation pattern having nulls. A set of connection pads couple the RF signal from the antenna to a frontend transmitter circuit of the RFID chip. A second antenna structure backscatters the received RF signal by electromagnetic coupling to the first antenna structure and produces a second radiation pattern that complements the nulls in the first radiation pattern.

Journal ArticleDOI
TL;DR: In this paper, physical bounds on the directivity Q-factor quotient and optimal current distributions are determined for antennas of arbitrary shape and size using an optimization formulation, where a variational approach offers closed form solutions for small antennas expressed in the polarizability of the antenna structure.
Abstract: Physical bounds on the directivity Q-factor quotient and optimal current distributions are determined for antennas of arbitrary shape and size using an optimization formulation. A variational approach offers closed form solutions for small antennas expressed in the polarizability of the antenna structure. Finite sized antennas are solved using Lagrangian parameters in a method of moments formulation. It is also shown that the optimal charge density for a small antenna can be generated by several current densities. Numerical examples for small and large antennas are used to illustrate the results.

Journal ArticleDOI
TL;DR: In this article, the authors proposed a novel wideband horizontally polarized omnidirectional printed loop antenna, which consists of a loop with periodical capacitive loading and a parallel stripline as an impedance transformer.
Abstract: This letter presents the design of a novel wideband horizontally polarized omnidirectional printed loop antenna. The proposed antenna consists of a loop with periodical capacitive loading and a parallel stripline as an impedance transformer. Periodical capacitive loading is realized by adding interlaced coupling lines at the end of each section. Similarly to mu-zero resonance (MZR) antennas, the periodical capacitive loaded loop antenna proposed in this letter allows current along the loop to remain in phase and uniform. Therefore, it can achieve a horizontally polarized omnidirectional pattern in the far field, like a magnetic dipole antenna, even though the perimeter of the loop is comparable to the operating wavelength. Furthermore, the periodical capacitive loading is also useful to achieve a wide impedance bandwidth. A prototype of the proposed periodical capacitive loaded loop antenna is fabricated and measured. It can provide a wide impedance bandwidth of about 800 MHz (2170-2970 MHz, 31.2%) and a horizontally polarized omnidirectional pattern in the azimuth plane.

Patent
04 Apr 2012
TL;DR: In this paper, an antenna for a medical device, e.g., an implantable medical device (IMD), comprises an electrically conductive wire that spirals to form a three-dimensional shape of a rectangular cuboid.
Abstract: In an embodiment, an antenna for a medical device, e.g., an implantable medical device (IMD), comprises an electrically conductive wire that spirals to form a three-dimensional shape of a rectangular cuboid. In another embodiment, the antenna comprises an electrically conductive wire that spirals to form a three-dimensional shape of an elliptical cylinder, an oval cylinder, an elongated pentagonal prism, an elongated hexagonal prism, or some other shape where the longitudinal diameter of the antenna is greater than the lateral diameter of the antenna. The antennas are sized to fit within a portion of a header of the medical device. Such antennas are designed to provide increased antenna gain and antenna bandwidth.

Journal ArticleDOI
03 Apr 2012
TL;DR: The four key technologies related to small antenna designs to be reviewed and discussed, including multiband planar inverted-F antennas, broadband folded patch antenna, compact differentially fed antennas, and miniature circularly polarized patch antennas, would cover a wide range of topical interests and practical applications.
Abstract: The objective of this paper is to provide the context, physical insight, and perspective on antennas in wireless communications. Although it does not mean to be comprehensive, the four key technologies related to small antenna designs to be reviewed and discussed, including multiband planar inverted-F antennas, broadband folded patch antennas, compact differentially fed antennas, and miniature circularly polarized patch antennas, would cover a wide range of topical interests and practical applications. A brief overview of computer software for analyzing these antennas is also provided. Hopefully, this paper will be beneficial for the diverse engineering readership of the IEEE.

Journal ArticleDOI
Kung Bo Ng1, Hang Wong1, Kwok Kan So1, Chi Hou Chan1, Kwai-Man Luk1 
TL;DR: In this paper, a planar electric dipole and a magnetic dipole formed by a vertically oriented shorted patch antenna are used for millimeter wave applications. But the antenna is realized by a plated through hole printed technique with the use of a microwave substrate and is excited by a T-shaped coupled strip feed.
Abstract: A wideband unidirectional antenna, which is composed of a planar electric dipole and a magnetic dipole formed by a vertically-oriented shorted patch antenna, is presented for millimeter wave applications. The antenna is realized by a plated through hole printed technique with the use of a microwave substrate and is excited by a T-shaped coupled strip feed. An impedance bandwidth of 33% (S11 ≤-15 dB) from 50 to 70 GHz is achieved. Stable radiation patterns with low cross polarizations and a stable antenna gain of ~7.5 dBi are achieved across the entire operating bandwidth. This single antenna element yields advantages of wideband, good directional radiation pattern and low fabrication cost.

Journal ArticleDOI
TL;DR: In this paper, a tri-band printed antenna for WLAN and WiMAX applications is presented, which consists of a modified rectangular slot, a pair of symmetrical inverted-L strips, and a Y-shaped monopole radiator with a meandering split-ring slot.
Abstract: A novel compact tri-band printed antenna for WLAN and WiMAX applications is presented. The proposed antenna consists of a modified rectangular slot, a pair of symmetrical inverted-L strips, and a Y-shaped monopole radiator with a meandering split-ring slot. Tuning the locations and the sizes of these structures, three distinct current paths can be produced at three independent frequency bands, respectively. Based on this concept, a prototype of the tri-band antenna is further fabricated and measured. The experimental and numerical results show that the antenna has impedance bandwidth (for return loss less than 10 dB) of 430 MHz (2.33-2.76 GHz), 730 MHz (3.05-3.88 GHz), and 310 MHz (5.57-5.88 GHz), which can cover both the WLAN 2.4/5.8-GHz bands and the WiMAX 2.5/3.5-GHz bands.

Journal ArticleDOI
TL;DR: In this paper, a beam reconfigurable antenna is proposed for THz application, which is based on a switchable high-impedance surface (HIS) using a single-layer graphene.
Abstract: In this paper, a new beam reconfigurable antenna is proposed for THz application, which is based on a switchable high-impedance surface (HIS) using a single-layer graphene. The effects of impurity density and gate voltage on the conductivity of graphene are utilized, and the switchable reflection characteristic of the graphene-based HIS is observed. Then the THz antenna is designed over this switchable HIS. By applying different voltages for different rows of HIS units, the antenna beam can be reconfigurable. The performance of the antenna is analyzed with its reflection coefficient, radiation pattern, and input impedance. The radiation beam of the antenna can vary in a range of ±30° as demonstrated by the simulated results.

Patent
18 May 2012
TL;DR: In this paper, a multi-band antenna component consisting of a carrier, a first antenna array, and a second antenna array is provided, composed of a ceramic material characterized by a permittivity of at least about 6.
Abstract: A multi-band antenna component is provided. The multi-band antenna component comprises a carrier, a first antenna array, and a second antenna array. The carrier is composed of a ceramic material characterized by a permittivity of at least about 6, said carrier having a first region and a second region distinct from the first region. The first antenna array is disposed on the first region and comprises one or more antennas selected from the group consisting of a first antenna adapted for about 2.4 GHz wireless communication, a second antenna adapted for about 5 GHz wireless communication, and a third antenna adapted for wireless communication for a global positioning system. The second antenna array is disposed on the second region and comprises at least one of a fourth antenna adapted for about 850 MHz wireless communication or a fifth antenna adapted for about 1800/1900 MHz wireless communication.