Showing papers on "Microstrip antenna published in 2014"
TL;DR: The challenges, benefits and approaches associated with realizing largescale antenna arrays at mmWave frequency bands for future 5G cellular devices are discussed, and a first-of- a-kind cellular phone prototype equipped with mmWave 5G antenna arrays consisting of a total of 32 low-profile antenna elements are developed.
Abstract: This article discusses the challenges, benefits and approaches associated with realizing largescale antenna arrays at mmWave frequency bands for future 5G cellular devices. Key design considerations are investigated to deduce a novel and practical phased array antenna solution operating at 28 GHz with near spherical coverage. The approach is further evolved into a first-of- a-kind cellular phone prototype equipped with mmWave 5G antenna arrays consisting of a total of 32 low-profile antenna elements. Indoor measurements are carried out using the presented prototype to characterize the proposed mmWave antenna system using 16-QAM modulated signals with 27.925 GHz carrier frequency. The biological implications due to the absorbed electromagnetic waves when using mmWave cellular devices are studied and compared in detail with those of 3/4G cellular devices.
509 citations
TL;DR: In this paper, a conformal wearable antenna that operates in the 2.36-2.4 GHz medical body-area network band is proposed, which is enabled by placing a highly truncated metasurface, consisting of only a two by two array of I-shaped elements, underneath a planar monopole.
Abstract: We propose a compact conformal wearable antenna that operates in the 2.36-2.4 GHz medical body-area network band. The antenna is enabled by placing a highly truncated metasurface, consisting of only a two by two array of I-shaped elements, underneath a planar monopole. In contrast to previously reported artificial magnetic conducting ground plane backed antenna designs, here the metasurface acts not only as a ground plane for isolation, but also as the main radiator. An antenna prototype was fabricated and tested, showing a strong agreement between simulation and measurement. Comparing to previously proposed wearable antennas, the demonstrated antenna has a compact form factor of 0.5 λ
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, all while achieving a 5.5% impedance bandwidth, a gain of 6.2 dBi, and a front-to-back ratio higher than 23 dB. Further numerical and experimental investigations reveal that the performance of the antenna is extraordinarily robust to both structural deformation and human body loading, far superior to both planar monopoles and microstrip patch antennas. Additionally, the introduced metal backed metasurface enables a 95.3% reduction in the specific absorption rate, making such an antenna a prime candidate for incorporation into various wearable devices.
301 citations
TL;DR: In this paper, a metamaterial-based broadband low-profile mushroom antenna is presented, which is formed using an array of mushroom cells and a ground plane, and fed by a microstrip line through a slot cut onto the ground plane.
Abstract: A metamaterial-based broadband low-profile mushroom antenna is presented. The proposed antenna is formed using an array of mushroom cells and a ground plane, and fed by a microstrip line through a slot cut onto the ground plane. With the feeding slot right underneath the center gap between the mushroom cells, the dual resonance modes are excited simultaneously for the radiation at boresight. A transmission-line model integrated with the dispersion relation of a composite right/left-handed mushroom structure is applied to analyze the modes. The proposed dielectric-filled (er=3.38) mushroom antenna with a low profile of 0.06λ0 ( λ0 is the operating wavelength in free space) and a ground plane of 1.10λ0×1.10λ0 attains 25% measured bandwidth with(|S11| <; - 10dB) 9.9-dBi average gain at 5-GHz band. Across the bandwidth, the antenna efficiency is greater than 76%, and cross-polarization levels are less than -20 dB.
290 citations
TL;DR: In this article, a planar polarization-reconfigurable metasurface antenna (PRMS) is proposed to operate at around 3.5 GHz with high-polarization isolation of larger than 15 dB.
Abstract: A planar polarization-reconfigurable metasurfaced antenna (PRMS) designed using metasurface (MS) is proposed. The PRMS antenna consists of a planar MS placed atop of and in direct contact with a planar slot antenna, both having a circular shape with a diameter of 78 mm (0.9 $\lambda_{0}$ ), making it compact and low profile. By rotating the MS around the center with respect to the slot antenna, the PRMS antenna can be reconfigured to linear polarization, left-hand and right-hand circular polarizations. An equivalent circuit is used to explain the reconfigurability of the antenna. The PRMS antenna is studied and designed to operate at around 3.5 GHz using computer simulation. For verification of simulation results, the PRMS antenna is fabricated and measured. The antenna performance, in terms of polarization reconfigurability, axial-ratio bandwidth, impedance bandwidth, realized boresight gain and radiation pattern, is presented. Results show that the PRMS antenna in circular polarizations achieves an operating bandwidth of 3.3–3.7 GHz (i.e., fractional bandwidth 11.4%), a boresight gain of above 5 dBi and high-polarization isolation of larger than 15 dB. While the PRMS antenna in linear polarization achieves a gain of above 7.5 dBi with cross-polarization isolation larger than 50 dB.
272 citations
TL;DR: A class of microstrip patch antennas that are stretchable, mechanically tunable, and reversibly deformable and well suited for applications like wireless strain sensing are demonstrated.
Abstract: We demonstrate a class of microstrip patch antennas that are stretchable, mechanically tunable, and reversibly deformable. The radiating element of the antenna consists of highly conductive and stretchable material with screen-printed silver nanowires embedded in the surface layer of an elastomeric substrate. A 3-GHz microstrip patch antenna and a 6-GHz 2-element patch array are fabricated. Radiating properties of the antennas are characterized under tensile strain and agree well with the simulation results. The antenna is reconfigurable because the resonant frequency is a function of the applied tensile strain. The antenna is thus well suited for applications like wireless strain sensing. The material and fabrication technique reported here could be extended to achieve other types of stretchable antennas with more complex patterns and multilayer structures.
270 citations
TL;DR: In this article, a broadband dual-polarized planar antenna is proposed for 2G/3G/LTE base stations, which is composed of two perpendicularly crossed bow-tie dipoles.
Abstract: A broadband dual-polarized planar antenna is proposed for 2G/3G/LTE base stations. The dual-polarized antenna is composed of two perpendicularly crossed bow-tie dipoles. Each bow-tie dipole is excited by a microstrip stub that is directly fed by a coaxial line, making the dual-polarized antenna full planar. Due to the coupling between two crossed bow-tie dipoles, a broad bandwidth is achieved. It is shown that the dual-polarized antenna has a bandwidth of 45% (1.7-2.7 GHz) for return loss >15 dB with an isolation of higher than 30 dB between two polarization input ports. The dual-polarized antenna has a half-power beam width (HPBW) of around 65 ° and an average gain of 8.5 dBi for slant ±45° polarizations. An 8-element dual-polarized planar antenna array is developed for base station applications. A bandwidth of 56% (1.63-2.9 GHz) is obtained for the antenna array. The antenna gain of the array is about 16 dBi and the HPBW is 65±8° for each polarization.
266 citations
TL;DR: In this paper, a circular phased array antenna that can generate orbital angular momentum (OAM) radio beams in the 10 GHz band is described, which consists of eight inset-fed patch elements and a microstrip corporate feeding network.
Abstract: A circular phased array antenna that can generate orbital angular momentum (OAM) radio beams in the 10 GHz band is described. The antenna consists of eight inset-fed patch elements and a microstrip corporate feeding network. A full-wave electromagnetic simulator is used to aid the antenna design and theoretical simulations are confirmed by measurements.
245 citations
TL;DR: In this article, a low-profile microstrip-fed compact triple band-notched ultrawideband (UWB) antenna is proposed, where two elliptic single complementary split-ring resonators (ESCSRRs) of different dimensions from the radiating patch of the antenna are etched out.
Abstract: In this letter, a novel low-profile microstrip-fed compact triple band-notched ultrawideband (UWB) antenna is proposed. Notch bands around the 3.3-3.8-GHz WiMAX and 5.15-5.85-GHz WLAN frequencies are obtained by etching out two elliptic single complementary split-ring resonators (ESCSRRs) of different dimensions from the radiating patch of the antenna. Furthermore, by placing two rectangular split-ring resonators near the feedline-patch junction of the antenna, rejection for the 7.9-8.4-GHz X-band frequencies is achieved. Design guidelines for implementing the notch-bands at the desired frequency regions are provided. The match between the simulated and experimental results suggests that the proposed antenna can be a good candidate for application in UWB communication systems.
234 citations
TL;DR: In this article, a single-fed miniaturized circularly polarized microstrip patch antenna is designed and experimentally demonstrated for industrial-scientific-medical (2.4-2.48 GHz) biomedical applications.
Abstract: A single-fed miniaturized circularly polarized microstrip patch antenna is designed and experimentally demonstrated for industrial-scientific-medical (2.4-2.48 GHz) biomedical applications. The proposed antenna is designed by utilizing the capacitive loading on the radiator. Compared with the initial topology of the proposed antenna, the so-called square patch antenna with a center-square slot, the proposed method has the advantage of good size reduction and good polarization purity. The footprint of the proposed antenna is 10×10×1.27 mm3. The simulated impedance, axial ratio, and radiation pattern are studied and compared in two simulation models: cubic skin phantom and Gustav voxel human body. The effect of different body phantoms is discussed to evaluate the sensitivity of the proposed antenna. The effect of coaxial cable is also discussed. Two typical approaches to address the biocompatibility issue for practical applications are reported as well. The simulated and measured impedance bandwidths in cubic skin phantom are 7.7% and 10.2%, respectively. The performance of the communication link between the implanted CP antenna and the external antenna is also presented.
230 citations
TL;DR: In this paper, a new concept for decoupling two coupled antenna elements in a broad band using a coupled resonator decoupled network (CRDN) is proposed for the first time, and two prototypes using microstrip resonators are designed and experimentally studied.
Abstract: A new concept for decoupling two coupled antenna elements in a broad band using a coupled resonator decoupling network (CRDN) is proposed for the first time. A synthesis and design theory of a CRDN is presented. Based on the admittance parameters of a given antenna array, a set of required rational functions and, consequently, the coupling matrix for a second-order decoupling network is obtained analytically. To prove the concept, two prototypes using microstrip resonators are designed and experimentally studied. Measurement results have demonstrated that an isolation improvement of more than 10 dB can be achieved within more than 15% bandwidth in both examples. The benefits of using a CRDN for different levels of isolation in a MIMO terminal are investigated through experiments and simulations. The results have shown that, as compared to the existing decoupling scheme using a lumped element, the proposed CRDN scheme can significantly increase the radiation efficiency, reduce the correlation, improve the channel capacity, and above all enhance the throughput of a MIMO terminal. The technique is general and can be applied to both symmetric and asymmetric arrays.
201 citations
29 Sep 2014
TL;DR: A circularly polarized microstrip rectangular patch antenna incorporated with a metamaterial slab will enhance the amount of transferred power to wireless sensors network with less radiation loss in WPT system.
Abstract: Wireless Power Transfer (WPT) system is a suitable alternative for power transmission where conventional wired power transfer faces geographical challenges. In a long range wireless power transmission system, power is transmitted through microwaves. A highly directive antenna is required for an effective transmission through this system. This paper talk about a circularly polarized microstrip rectangular patch antenna incorporated with a metamaterial slab. Use of microstrip antennas will considerably reduce the size of WPT system in comparison to other microwave antenna. In this paper the modeling and analysis of the wireless power transmission system is done on 2.45 GHz frequency and using GaAs Schottky barrier diode for the rectification of microwave power to DC power at the receiver end. Antenna assigned with metamaterial proposed in paper will enhance the amount of transferred power to wireless sensors network with less radiation loss.
TL;DR: In this article, the authors presented a 32 $\,\times\,$ 32 high-gain patch array antenna fed by the substrate integrated waveguide (SIW) structure at W-band.
Abstract: This communication presents a 32 $\,\times\,$ 32 high-gain patch array antenna fed by the substrate integrated waveguide (SIW) structure at W-band. The array antenna consists of two layers to achieve a compact topology, which allows for mass production using a standard PCB fabrication process. The wideband feeding network is placed in the bottom layer while the radiating patches are on the top layer. This configuration also resolves the trade-off between gain and bandwidth of conventional SIW array antennas. Measured gain of the 32 $\,\times\,$ 32 antenna array is within the range 28.81–29.97 dBi in the working bandwidth of 91–97 GHz. Measured impedance bandwidth covers the same frequency band for $\vert {\rm S} _{11} \vert . The cross-polarization of the antenna array is less than 40 dB at the beam direction. Good agreement between the simulated and measured results validates our design.
TL;DR: A fully textile microstrip topology with ultra wideband (UWB) characteristics useful in wireless body area networks (WBAN) is proposed, which successfully reduces any on-body performance degradation, resulting in a very robust structure.
Abstract: A fully textile microstrip topology with ultra wideband (UWB) characteristics useful in wireless body area networks (WBAN) is proposed. The antenna is operable within the full UWB band and incorporates a full textile shielding ground plane. The full ground plane is shown to be crucial in maintaining the performance when worn on-body. It successfully reduces any on-body performance degradation, resulting in a very robust structure. A detailed numerical and experimental evaluation of the antenna is performed in free space and on body.
TL;DR: In this paper, a low-cost single-layer wideband microstrip antenna array is presented for 60 GHz band applications. But the proposed array is excited by a novel coplanar waveguide feed network, which not only has a simple structure by abandoning the traditional air bridges (wire bonds) above the CPW T-junctions but also provides pairs of broadband differential outputs.
Abstract: A low-cost single-layer wideband microstrip antenna array is presented for 60-GHz band applications. Each microstrip radiation element is fed by a modified L-shaped probe to enhance the impedance bandwidth. The proposed microstrip antenna array is excited by a novel coplanar waveguide (CPW) feed network, which not only has a simple structure by abandoning the traditional air bridges (wire bonds) above the CPW T-junctions but also provides pairs of broadband differential outputs. Experimentally, two 4 $\,\times\,$ 4 antenna arrays with different polarizations were designed and fabricated on the double-sided single-layer printed circuit board. The linearly polarized array exhibits an impedance bandwidth ( ${\hbox{SWR}}\leq 2$ ) of 25.5% and a gain of around 15.2 dBi. The circularly polarized array, employing the same CPW feed network to excite sequentially rotated circularly polarized elements, achieves an impedance bandwidth ( ${\hbox{SWR}}\leq 2$ ) of 17.8%, a 3-dB axial ratio bandwidth of 15.6%, and a gain of around 14.5 dBi.
TL;DR: An implantable rectenna, which consists of a planar inverted-F antenna (PIFA) and a rectifier circuit, is proposed for far-field wireless power transfer and a method of adding a parasitic patch over the human body is used to enhance the wireless power link.
Abstract: An implantable rectenna, which consists of a planar inverted-F antenna (PIFA) and a rectifier circuit, is proposed for far-field wireless power transfer. The PIFA has a folded ground plane to miniaturize its size. The performance of the wireless power link between the implanted antenna and an external antenna is examined. A method of adding a parasitic patch over the human body is used to enhance the wireless power link, thus to increase the received power level. Safety considerations of far-field RF powering are discussed. The RF-to-DC conversion circuit efficiency is optimized after the receiver power level of the implantable antenna is estimated based on the safety considerations. Finally, a rectifier circuit and an integrated rectenna solution are discussed.
TL;DR: In this paper, a dual-band textile antenna with an AMC plane is proposed for WLAN applications, which is enabled by a rectangular patch in the 2.4 GHz band and a patch-etched slot dipole in the 5 GHz band.
Abstract: A dual-band textile antenna loaded with an artificial magnetic conductor (AMC) plane is proposed for WLAN applications. Its dual-band operation is enabled by a rectangular patch in the 2.4 GHz band and a patch-etched slot dipole in the 5 GHz band. Since the AMC approaches a perfect magnetic conductor (PMC) in the 5 GHz band, the slot dipole can be located close to the ground. The proposed antenna is fully fabricated using textiles except for a feeding connector used for testing purposes and a via. Simulations and experiments agree well and validate that this low profile antenna operates with a good reflection coefficient and a high front-to-back ratio (FBR) within the desired bands.
TL;DR: In this paper, a partially reflecting surface (PRS) was proposed to reduce the radar cross section (RCS) and enhance the gain of a patch antenna by using two layers of metallic patterns on both sides of a dielectric slab.
Abstract: We propose a novel design to reduce the radar cross section (RCS) and enhance the gain of a patch antenna by using partially reflecting surface (PRS). The PRS consists of two layers of metallic patterns on both sides of a dielectric slab. The metallic pattern on the bottom side is utilized to construct Fabry-Perot resonance cavity with ground plane of a patch antenna, while it is designed to absorb most of the incident wave on the top side. The PRS can enable the patch antenna to simultaneously achieve high gain and low RCS. Measurement results show that the antenna gain is enhanced by about 6.5 dB at 11.5 GHz, and its RCS is dramatically reduced in a broad frequency range from 6 to 14 GHz, compared with the traditional patch antenna without the PRS.
TL;DR: In this paper, a screen-printed interface layer was used to reduce the surface roughness of the polyester/cotton material that facilitated the printing of a continuous conducting surface.
Abstract: This letter introduces a new technique of inkjet printing antennas on textiles. A screen-printed interface layer was used to reduce the surface roughness of the polyester/cotton material that facilitated the printing of a continuous conducting surface. Conducting ink was used to create three inkjet-printed microstrip patch antennas. An efficiency of 53% was achieved for a fully flexible antenna with two layers of ink. Measurements of the antennas bent around a polystyrene cylinder indicated that a second layer of ink improved the robustness to bending.
TL;DR: In this paper, a frequency-reconfigurable antenna designed using metasurface (MS) to operate at around 5 GHz is proposed and studied. But the MS placed atop the patch antenna behaves like a dielectric substrate and rotating the MS changes the equivalent relative permittivity of the substrate and hence the operating frequency of the FRMS antenna.
Abstract: A frequency-reconfigurable antenna designed using metasurface (MS) to operate at around 5 GHz is proposed and studied. The frequency-reconfigurable metasurfaced (FRMS) antenna is composed of a simple circular patch antenna and a circular MS with the same diameter of 40 mm (0.67 λ) and implemented using planar technology. The MS is placed directly atop the patch antenna, making the FRMS antenna very compact and low profile with a thickness of only 3.048 mm (0.05 λ). The MS consists of rectangular-loop unit cells placed periodically in the vertical and horizontal directions. Simulation results show that the operating frequency of the antenna can be tuned by physically rotating the MS around the center with respect to the patch antenna. The MS placed atop the patch antenna behaves like a dielectric substrate and rotating the MS changes the equivalent relative permittivity of the substrate and hence the operating frequency of the FRMS antenna. Measured results show that the antenna has a tuning range from 4.76 to 5.51 GHz, a fractional tuning range of 14.6%, radiation efficiency and a realized peak gain of more than 80% and 5 dBi, respectively, across the tuning range.
TL;DR: This paper provides a methodology to design reconfigurable antennas with radio frequency microelectromechanical system (RF-MEMS) switches using particle swarm optimization, a nature-inspired optimization technique.
Abstract: Reconfigurable antennas offer attractive potential solutions to solve the challenging antenna problems related to cognitive radio systems using the ability to switch patterns, frequency, and polarization. In this paper, a novel frequency reconfigurable E-shaped patch design is proposed for possible applications in cognitive radio systems. This paper provides a methodology to design reconfigurable antennas with radio frequency microelectromechanical system (RF-MEMS) switches using particle swarm optimization, a nature-inspired optimization technique. By adding RF-MEMS switches to dynamically change the slot dimensions, one can achieve wide bandwidth which is nearly double the original E-shaped patch bandwidth. Utilizing an appropriate fitness function, an optimized design which works in the frequency range from 2 GHz to 3.2 GHz (50% impedance bandwidth at 2.4 GHz ) is obtained. RF-MEMS switch circuit models are incorporated into the optimization as they more effectively represent the actual switch effects. A prototype of the final optimized design is developed and measurements demonstrate good agreement with simulations.
TL;DR: In this paper, a new type of wideband substrate integrated waveguide (SIW) cavity-backed patch antenna and array for millimeter wave (mmW) are investigated and implemented.
Abstract: In this letter, a new type of wideband substrate integrated waveguide (SIW) cavity-backed patch antenna and array for millimeter wave (mmW) are investigated and implemented. The proposed antenna is composed of a rectangular patch with a backed SIW cavity. In order to enhance the bandwidth and radiation efficiency, the cavity is designed to resonate at its TE210 mode. Based on the proposed antenna, a 4 × 4 array is also designed. Both the proposed antenna and array are fabricated with standard printed circuit board (PCB) process, which possess the advantage of easy integration with planar circuits. The measured bandwidth (|S11| ≤ -10 dB) of the antenna element is larger than 15%, and that of the antenna array is about 8.7%. The measured peak gains are 6.5 dBi for the element and 17.8 dBi for the array, and the corresponding simulated radiation efficiencies are 83.9% and 74.9%, respectively. The proposed antenna and array are promising for millimeter-wave applications due to its merits of wide band, high efficiency, low cost, low profile, etc.
TL;DR: A new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for future fifth generation (5G) cellular networks is presented and can be considered as a good candidate for 5G communication applications.
Abstract: In this paper, a new dense dielectric (DD) patch array antenna prototype operating at 28 GHz for future fifth generation (5G) cellular networks is presented. This array antenna is proposed and designed with a standard printed circuit board process to be suitable for integration with radio frequency/microwave circuitry. The proposed structure employs four circular-shaped DD patch radiator antenna elements fed by a 1-to-4 Wilkinson power divider. To improve the array radiation characteristics, a ground structure based on a compact uniplanar electromagnetic bandgap unit cell has been used. The DD patch shows better radiation and total efficiencies compared with the metallic patch radiator. For further gain improvement, a dielectric layer of a superstrate is applied above the array antenna. The measured impedance bandwidth of the proposed array antenna ranges from 27 to beyond 32 GHz for a reflection coefficient (S11) of less than -10 dB. The proposed design exhibits stable radiation patterns over the whole frequency band of interest, with a total realized gain more than 16 dBi. Due to the remarkable performance of the proposed array, it can be considered as a good candidate for 5G communication applications.
TL;DR: In this paper, a low-cost high-gain and broadband substrate integrated waveguide (SIW)-fed patch antenna array is demonstrated at the 60 GHz band, where a single-layered SIW feeding network with wideband T-junctions and wideband high gain cavity-backed patch antennas are employed to achieve high gain and wide-band performance simultaneously.
Abstract: A low-cost high-gain and broadband substrate integrated waveguide (SIW)-fed patch antenna array is demonstrated at the 60-GHz band. A single-layered SIW feeding network with wideband T-junctions and wideband high-gain cavity-backed patch antennas are employed to achieve high gain and wideband performance simultaneously. Although the proposed antenna array has a multilayered structure, it can be fabricated by conventional low-cost single-layered printed circuit board (PCB) technology and then realized by stacking and fixing all of single layers together. The simulated and measured impedance bandwidths of a 4 × 4 antenna array are 27.5% and 22.6% for 10 dB. The discrepancy between simulation and measurement is analyzed. A gain up to 19.6 dBi, and symmetrical unidirectional radiation patterns with low cross polarization are also achieved. With advantages of low fabrication cost and good performances, the proposed antenna array is a promising candidate for millimeter-wave wireless communication systems.
TL;DR: In this paper, a comprehensive analysis aimed at reducing the radar cross section (RCS) of array antennas, preserving at the same time their radiating performance, is presented, where a microstrip slot array is considered as a test case to illustrate the proposed strategy for radar cross-section reduction (RCSR).
Abstract: A comprehensive analysis aimed at reducing the radar cross section (RCS) of array antennas, preserving at the same time their radiating performance, is presented. A microstrip slot array is considered as a test case to illustrate the proposed strategy for radar cross section reduction (RCSR). It is shown that a remarkable reduction of the radar signature can be accomplished over a frequency band as wide as two octaves by employing an array of periodic resistive elements in front of the radiating apertures. The monostatic and bistatic RCS of the proposed structures are investigated both for normal and oblique incidence. Different arrangements and geometries of the periodic resistive pattern are thoroughly analyzed showing the benefits and the drawbacks in terms of antenna gain and level of the scattered fields. Furthermore, the use of metallic parasitic elements for enhancing the antenna gain is considered, and the scattering phenomena caused by their presence are addressed, taking into account the appearance of grating lobes. The antenna designs are also analyzed by resorting to a bidimensional color plot presenting the variation of the reradiated field both in frequency and spatial domain. The guidelines illustrated by the proposed examples can be easily applied to other antenna architectures.
Patent•
17 Feb 2014
TL;DR: In this article, a multiband common-caliber antenna with a continuous transverse stub (CTS) antenna and a microstrip patch antenna is presented. But the CTS antenna does not have an antenna array array array.
Abstract: An embodiment of the present invention provides a multiband common-caliber antenna. The multiband common-caliber antenna of the present invention comprises a continuous transverse stub (CTS) antenna and a microstrip patch antenna. The CTS antenna comprises a planar waveguide feeding structure and multiple strip-shaped waveguide radiation units disposed on the planar waveguide feeding structure and disposed in a spaced manner along a first direction. A medium substrate is disposed between every two strip-shaped waveguide radiation units and on the upper surface of the planar waveguide feeding structure. Microstrip patch antenna arrays are disposed on the upper surface of the medium substrate. Each of the microstrip patch antenna arrays comprises multiple microstrip patch antenna units disposed in a spaced manner along a second direction perpendicular to the first direction. The number of the microstrip patch antenna arrays disposed on at least one of the medium substrate is not less than 2. The microstrip patch antenna arrays disposed on the medium substrates form the microstrip patch antenna. The embodiment of the present invention suppresses mutual coupling between surface waves of the microstrip patch antenna and the antenna.
TL;DR: In this article, a selective frequency-reconfigurable antenna is proposed for cognitive radio applications. But the antenna is composed of a radiating element in the form of an inverted U fed by a microstrip line on its upper side.
Abstract: This letter presents a selective frequency-reconfigurable antenna, suitable for cognitive radio applications. The proposed antenna is capable of switching between a wide operating band of 2.63-3.7 GHz and four different subbands, which allows using it for sensing the entire band and then adjusting its bandwidth to select the suitable sub-band and prefilter out the other ones. The antenna is composed of a radiating element in the form of an inverted U fed by a microstrip line on its upper side. In order to achieve a selective frequency reconfiguration, four horizontal slots with integrated p-i-n diode switches are incorporated in the ground plane to act as reconfigurable filter. Some of the switches are used to alter the antenna bandwidth, while the others are employed to shift the operating band by varying the electrical length of the middle slots. To present the work, both simulated and measured results are presented, and a good agreement is achieved.
TL;DR: In this paper, the authors proposed a new approach to generate a non-zero OAM fleld through a single patch antenna, which can be used as compact and low-cost generators of electromagnetic flelds carrying OAM.
Abstract: The recent extension of the orbital angular momentum (OAM) concept from optical to microwave frequencies has led some researchers to explore how well established antenna techniques can be used to radiate a non-zero OAM electromagnetic fleld. In this frame, the aim of the present paper is to propose a new approach to generate a non-zero OAM fleld through a single patch antenna. Using the cavity model, we flrst analyze the radiated fleld by a standard circular patch and show that a circular polarized (CP) TMnm mode excited by using two coaxial cables generates an electromagnetic fleld with an OAM of order §(ni1). Then, in order to obtain a simpler structure with a single feed, we design an elliptical patch antenna working on the right-handed (RH) CP TM21 mode. Using full-wave simulations and experiments on a fabricated prototype, we show that the proposed antenna efiectively radiates an electromagnetic fleld with a flrst order OAM. Such results prove that properly designed patch antennas can be used as compact and low-cost generators of electromagnetic flelds carrying OAM.
TL;DR: The proposed antenna consisting of graphene nano ribbon as radiating patch and also the ground plane separated by a 20 μm thin polyimide substrate has achieved the broad impedance bandwidth (>5%) in the band of operation.
TL;DR: In this paper, the design of a novel differentially fed dual-band implantable antenna operating at 402-405 MHz Medical Implant Communication Services (MICS) band and 2.4-2.5 GHz Industrial, Scientific, and Medical (ISM) band is introduced.
Abstract: The design of a novel differentially fed dual-band implantable antenna operating at 402-405 MHz Medical Implant Communication Services (MICS) band and 2.4-2.5 GHz Industrial, Scientific, and Medical (ISM) band is introduced. The proposed implanted antennas are for both planar and flexible implantation scenarios. Biocompatible material parylene-C is adopted to cover the implanted antenna. The size of the proposed antennas including the encapsulation for planar and flexible case is 179.0 mm3 and 186.3 mm3 respectively. The Specific Absorption Rate (SAR) distribution and the radiation pattern at both frequencies induced by the implanted antenna are evaluated. The performance of the communication link between the implanted antenna and an external half-wavelength dipole at two resonant frequencies is also presented. In vitro test in minced pork is performed to test the reliability of the antenna in the real implantation cases.
TL;DR: In this paper, a low-cost method for generating circular polarization in a dielectric resonator antenna is proposed, which consists of four rectangular layers, each one being rotated by an angle of 30 degrees relative to its adjacent layers.
Abstract: A novel low-cost method for generating circular polarization in a dielectric resonator antenna is proposed. The antenna comprises four rectangular dielectric layers, each one being rotated by an angle of 30 ° relative to its adjacent layers. Utilizing such an approach has provided a circular polarization over a bandwidth of 6% from 9.55 to 10.15 GHz. This has been achieved in conjunction with a 21% impedance-matching bandwidth over the same frequency range. Also, the radiation efficiency of the proposed circularly polarized dielectric resonator antenna is 93% in this frequency band of operation