Showing papers on "Folded inverted conformal antenna published in 2009"
TL;DR: In this paper, a printed monopole antenna for ultrawideband (UWB) applications is proposed, which consists of a square radiating patch with two rectangular slots and a ground plane with inverted T-shaped notch, providing a wide usable fractional bandwidth of more than 120% (3.1212.73 GHz).
Abstract: In this letter, we present a novel printed monopole antenna for ultrawideband (UWB) applications. The proposed antenna consists of a square radiating patch with two rectangular slots and a ground plane with inverted T-shaped notch, which provides a wide usable fractional bandwidth of more than 120% (3.1212.73 GHz). The proposed antenna is simple and small in size. Simulated and experimental results obtained for this antenna show that it exhibits good radiation behavior within the UWB frequency range.
217 citations
TL;DR: In this article, a planar antenna using a doubly resonant transmission line metamaterial (TL-MTM) structure is proposed, which is well matched to 50 Omega through an embedded series meandered line.
Abstract: A wideband and compact planar antenna is proposed using a doubly resonant transmission-line metamaterial (TL-MTM) structure. The antenna consists of two TL-MTM arms that resonate at different frequencies. Each arm comprises a microstrip transmission-line loaded with five spiral inductors and is well matched to 50 Omega through an embedded series meandered line. Each arm is designed to work as a single antenna at its own resonant frequency, determined by the loading spiral inductance, where a zero insertion phase occurs. A wideband antenna matching is enabled when these two resonances suitably merge together. A fabricated prototype has dimensions of lambdao/4 times lambdao/7 times lambdao/29, yielding a vertical linear electric field polarization, and provides a 100-MHz bandwidth (-10 dB) with a measured radiation efficiency of 65.8% at 3.30 GHz.
198 citations
01 Jan 2009
TL;DR: In this paper, the authors present a survey of the basic designs of microstrip antennas, including the use of the TM11 (linear and broadside CP), TM21 (monopole CP pattern) and TM02 (mono-linear linear) circular patch modes in designs, dual-band antenna designs which allow for independent dualband frequencies.
Abstract: The approach in this book is historical and practical. It covers basic designs in more detail than other microstrip antenna books that tend to skip important electrical properties and implementation aspects of these types of antennas. Examples include: quarter-wave patch, quarter by quarter patch, detailed design method for rectangular circularly polarized patch, the use of the TM11 (linear and broadside CP), TM21 (monopole CP pattern) and TM02 (monopole linear) circular patch modes in designs, dual-band antenna designs which allow for independent dual-band frequencies. Limits on broadband matching are discussed. The appendix contains useful simple matching approaches, design details (gain, matching, sidelobes) of the little-studied omnidirectional microstrip antenna (OMA), limits and properties of common single and dual band Planar Inverted F Antenna (PIFA) antenna designs. The second edition has numerous additions to the earlier text which will make the concepts presented clearer. New cavity model analysis equations of circular polarization bandwidth, axial ratio bandwidth and power fraction bandwidth have been included. The section on omnidirectional microstrip antennas is expanded with further design options and analysis. This is also true of the section on Planar Inverted F (PIFA) antennas. The discovery and description of the fictious resonance mode of a microstrip slot antenna has been added to that section. Appendix A, on microstrip antenna substrates has been expanded to provide more detail on the types of substrate and their composition. This is often neglected in other texts. An appendix on elementary impedance matching techniques has been added as these methods have proven useful in my industrial work.
188 citations
TL;DR: A method to derive the transfer function of the antenna has been proposed, which can be used to obtain the radiated pulses in the time domain, and a parametric study is conducted to provide antenna engineers with useful information for designing and optimizing the antenna.
Abstract: A compact diversity antenna operating at an ultrawideband (UWB) frequency range of 3.1-5 GHz is proposed for use in portable devices. The antenna printed on a printed circuit board (PCB) slab consists of two notched triangular radiating elements with two feeding ports. A ground plane is etched on the reverse side of the PCB. The shape of the ground plane is optimized to improve the isolation between the ports as well as impedance matching. The simulated and measured results show that across the operating bandwidth, the antenna can achieve a broad impedance bandwidth with good performance in terms of isolation of -2 dBi, and efficiency of > 70%. The correlation between the radiation patterns shows consistent diversity performance across the UWB bandwidth. A method to derive thetransfer function of the antenna has been proposed, which can be used to obtain the radiated pulses in the time domain. Furthermore, a parametric study is conducted to provide antenna engineers with useful information for designing and optimizing the antenna.
170 citations
TL;DR: In this article, a mechanically flexible planar inverted cone antenna (PICA) for ultrawideband (UWB) applications is presented, which can be both folded and stretched significantly without permanent damage or loss of electrical functionality.
Abstract: A mechanically flexible planar inverted cone antenna (PICA) for ultrawideband (UWB) applications is presented. It can be both folded and stretched significantly without permanent damage or loss of electrical functionality. The antenna is manufactured with a process in which conductors are realized by injecting room temperature liquid metal alloy into micro-structured channels in an elastic dielectric material. The elastic dielectric material together with the liquid metal enables bending with a very small radius, twisting, and stretching along any direction. Port impedance and radiation characteristics of the non-stretched and stretched antenna are studied in simulations and experiments. The presented antenna has a return loss better than 10 dB within 3-11 GHz and a radiation efficiency of > 70% over 3-10 GHz, also when stretched. Tests verify that stretching up to 40% is possible with maintained electrical performance. The presented antenna is useful for example for body-worn antennas and in applications in harsh environments where mechanical flexibility helps improve durability.
154 citations
TL;DR: In this article, a multiband printed monopole slot antenna is proposed for operating as an internal antenna in the thin-profile laptop computer for wireless wide area network (WWAN) operation.
Abstract: A multiband printed monopole slot antenna promising for operating as an internal antenna in the thin-profile laptop computer for wireless wide area network (WWAN) operation is presented. The proposed antenna is formed by three monopole slots operated at their quarter-wavelength modes and arranged in a compact planar configuration. A step-shaped microstrip feedline is applied to excite the three monopole slots at their respective optimal feeding position, and two wide operating bands at about 900 and 1900 MHz are obtained for the antenna to cover all the five operating bands of GSM850/900/1800/1900/UMTS for WWAN operation. The antenna is easily printed on a small-size FR4 substrate and shows a length of 60 mm only and a height of 12 mm when mounted at the top edge of the system ground plane or supporting metal frame of the laptop display. Details of the proposed antenna are presented and studied.
138 citations
TL;DR: In this paper, the design, simulation and fabrication of a left-handed metamaterial (LHM) structure was presented, where the combination of the modifled square rectangular Split Ring Resonator (SRR) and the Capacitance Loaded Strip (CLS) were used to obtain the negative value of permeability, " and the negative permittivity, ". Nicolson- Ross-Wier approach was used to identify the double negative region.
Abstract: The design, simulation and fabrication of a left-handed metamaterial (LHM) structure is presented. The combination of the modifled square rectangular Split Ring Resonator (SRR) and the Capacitance Loaded Strip (CLS) were used to obtain the negative value of permeability, " and the negative permittivity, ". Nicolson- Ross-Wier approach was used to identify the double negative region. A good agreement between simulated and measured results has been achieved. Upon incorporation with a single patch microstrip antenna, the performance of the antenna was improved where the gain of the microstrip antenna was increased up to 4dB, and its bandwidth widens from 2.9% to 4.98%. These improvements are due to the negative refraction characteristics of the LHM structure that acts as a lens when placed in front of the antenna.
130 citations
TL;DR: In this article, a broadband inverted E-H shaped microstrip patch antenna is proposed and experimentally investigated for electromagnetic analysis including the impedance bandwidth, radiation pattern, and antenna gain.
Abstract: A broadband inverted E-H shaped microstrip patch antenna is proposed and experimentally investigated. The antenna employs novel E-H shaped patch with L-probe feed technique. Prototype of the proposed antenna has been fabricated and measured for electromagnetic analysis including the impedance bandwidth, radiation pattern, and antenna gain. The designed antenna has a dimension of 80mm by 50mm, leading to broad bandwidths covering 1.76GHz to 2.38GHz. Stable radiation patterns across the operating bandwidth are observed. In addition, a parametric study is conducted to facilitate the design and optimization process.
129 citations
TL;DR: In this paper, the authors proposed a broadband rectangular microstrip antenna (MSA) by cutting a half-U-slot and rectangular slot on the edges of the patch, which has broadside radiation pattern over the entire bandwidth.
Abstract: The broadband and compact rectangular microstrip antenna (MSA) is realized either by cutting a half-U-slot or rectangular slot inside the patch In this letter, broadband rectangular microstrip antenna, by cutting a half-U-slot and rectangular slot on the edges of the patch, is proposed Due to the two resonant slots, the antenna gives more bandwidth as compared to only a rectangular-slot-cut or a half-U-slot-cut rectangular microstrip antenna The proposed antenna has broadside radiation pattern over the entire bandwidth
102 citations
TL;DR: A comparison with that of the existing antennas showed that wide impedance bandwidth of the proposed structure can be achieved without increasing the implementation complexity.
Abstract: A compact internal antenna is proposed for GSM/GPS/DCS/PCS/UMTS/Bluetooth/WLAN/WiFi/WiMAX applications. The proposed antenna is comprised of a loop antenna and a monopole antenna. The antenna system shows wide multi-operation band as well as good radiation patterns and small volume. The antenna can be printed on the system circuit board of the mobile phone and short-circuited to the system ground plane to form a loop-type structure. A comparison with that of the existing antennas showed that wide impedance bandwidth of the proposed structure can be achieved without increasing the implementation complexity.
99 citations
TL;DR: The design of a novel Fractal planar inverted F antenna (F-PIFA) based on the self affinity property has met the performance criteria for a mobile phone application.
Abstract: The design of a novel Fractal planar inverted F antenna (F-PIFA) based on the self affinity property is presented in this paper. The procedure for designing a Fractal Planar Inverted F Antenna is explained and three different iterations are designed for use in cellular phones. The F-PIFA has a total dimension of 27 mm × 27 mm and has been optimized to be operational at GSM (Global System for Mobile Communication), UMTS (Universal Mobile Telecommunication System) and HiperLAN (High Performance Radio LAN) with the frequencies range from 1900 MHz to 2100 MHz, 1885 to 2200 MHz and 4800 MHz to 5800 MHz respectively. The antenna achieved −6 dB return loss at the required GSM, UMTS and HiperLan frequencies with and has almost omnidirectional radiation pattern. This antenna has been tested using realistic mobile phone model and has met the performance criteria for a mobile phone application. Simple semi-empirical formulas of the operational frequency, numerical calculation and computational SAR of the antenna also has been presented and discussed.
TL;DR: In this article, a reconfigurable single folded slot antenna is shown, where metal strips are used in the slot to manipulate the ground size around the slot, which yields to changing the slot's perimeter and thus changing the resonant frequency of the antenna.
Abstract: The design of a reconfigurable single folded slot antenna is shown. Metal strips are used in the slot to manipulate the ground size around the slot, which yields to changing the slot's perimeter and thus changing the resonant frequency of the antenna. The design of a single folded slot antenna is first illustrated. Later, the design is modified to be reconfigurable. The resonant frequencies for the reconfigurable design are chosen to be applicable with the WLAN applications. The antenna design, simulation, and measurements are described. The simulated results both for the return loss and maximum gain agree with the measurements. The antenna has similar radiation patterns in both bands. The advantage of this design is that the length of the bias lines does not affect the antenna performance, thus making its design, feeding, and matching an extremely simple and low-cost procedure for antenna designers.
TL;DR: In this article, a new high gain wideband L-probe fed inverted EE-H shaped slotted (LEE-H) microstrip patch antenna is presented in which the antenna exhibits stable radiation pattern in the entire operating band.
Abstract: A new high gain wideband L-probe fed inverted EE-H shaped slotted (LEE-H) microstrip patch antenna is presented in this paper. The design adopts contemporary techniques; L-probe feeding, inverted patch structure with air-fllled dielectric, and EE-H shaped patch. The integration of these techniques leads to a new patch antenna with a low proflle as well as useful operational features, as the broadband and high gain. The measured result showed satisfactory performance with achievable impedance bandwidth of 21.15% at 10dB return loss (VSWR • 2) and a maximum gain of 9.5dBi. The antenna exhibits stable radiation pattern in the entire operating band.
TL;DR: In this paper, a generalized approach to design an electromagnetically coupled microstrip ring antenna for dual-band operation is presented, where a stub is attached to the inner edge of the side opposite to the feed arm to compensate for the losses in electrical length caused by widening.
Abstract: This paper presents a generalized approach to design an electromagnetically coupled microstrip ring antenna for dual-band operation. By widening two opposite sides of a square ring antenna, its fractional bandwidth at the primary resonance mode can be increased significantly so that it may be used for practical applications. By attaching a stub to the inner edge of the side opposite to the feed arm, some of the losses in electrical length caused by widening can be regained. More importantly, this addition also alters the current distribution on the antenna and directs radiations at the second resonant frequency towards boresight. It has also been observed that for the dual frequency configurations studied, the ratio of the resonant frequencies (center dot r(2)center dot center dot r(1)) can range between 1.55 and 2.01. This shows flexibility in designing dual frequency antennas with a desired pair of resonant frequencies.
TL;DR: In this article, a planar inverted-F antenna (PIFA) consisting of two meandered strips with bandwidth enhancement technique is proposed for implantable biotelemetry in MICS band.
Abstract: A compact planar inverted-F antenna (PIFA) consisted of two meandered strips with bandwidth enhancement technique is proposed for implantable biotelemetry in MICS band. The antenna occupies a volume of only 791 mm3 (22.5 mm by 18.5 mm by 1.9 mm) operating at 402 MHz. PIFA with two meandered strips can excite dual-resonate frequencies that control the resonant frequencies at 380 and 440 MHz, respectively, to obtain the broad bandwidth of 120 MHz (353–473 MHz) at a return loss of 10 dB. To verify the performance of implantable antenna, the test tissue is adopted as implanting environment by grinding the pork of front-leg. Furthermore, the property of this antenna can remain consistency against the varying and complex human tissue. Thus, this letter provides a miniature, broadband implantable PIFA for biotelemetry of medical devices. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 749–752, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24189
TL;DR: In this article, a printed Cantor fractal monopole antenna using multifractal technique is proposed, which has multi-band characteristics covering GSM, DCS, PCS, UMTS and WLAN applications.
Abstract: A novel printed Cantor fractal monopole antenna using multifractal technique is proposed. The antenna has multi-band characteristics covering GSM, DCS, PCS, UMTS, and WLAN applications. Prototypes of the multiband antenna have been implemented and the return loss has been compared with that of measured value. The use of multifractal concept in the Cantor antenna design makes it flexible in terms of controlling resonance and bandwidth.
TL;DR: In this paper, an internal multiband inverted-F antenna (IFA) design for mobile device applications is proposed, which is comprised of a dual-band main inverted-f resonator and two parasitic elements to broaden the bandwidth.
Abstract: This letter proposes an internal multiband inverted-F antenna (IFA) design for mobile device applications. The proposed antenna is comprised of a dual-band main inverted-F resonator and two parasitic elements to broaden the bandwidth. The operating bands are able to cover GSM900/DCS/PCS/UMTS2100/WiMAX /HIPERLAN2/IEEE802.11a/b/g. This work performs a simulation by HFSS to design the antenna and fabricates a practical structure. The measured data compared with the simulation results show good agreement. Since the occupied volume measures only 50 times 12 times 1.5 mm3, it is suitable for portable devices.
TL;DR: In this paper, a wideband and broad-beam microstrip antenna with gaps and stubs is proposed, which is based on atwo-layer stacked electromagnetic coupling microstrip patch antenna (ECMSA).
Abstract: A novel wideband and broad-beam microstrip antenna loaded with gaps and stubs is proposed. The antenna is based on atwo-layer stacked electromagnetic coupling microstrip patch antenna (ECMSA). The upper patch of the antenna is loaded with two arc gaps and three stubs. The ECMSA is used to achieve wide impedance bandwidth, while the gaps and stubs-loaded patch is used to obtain broad-beam. The impedance bandwidth is up to 34.6%. In this impedance bandwidth, the pattern bandwidth is 13%. In this pattern bandwidth, the 3%dB beamwidth of E-plane and H-plane remain stable and are about %60%. Simulation results agree well with measured results.
TL;DR: An integrated dual planar inverted-F antenna (PIFA) with enhanced isolation is proposed in this article, which is composed of two PIFAs merged together through a common metallic strip and a via connected to the ground plane.
Abstract: An integrated dual planar inverted-F antenna (PIFA) with enhanced isolation is proposed. The antenna is composed of two PIFAs merged together through a common metallic strip and a via connected to the ground plane. An additional folded resonator with electrical length of about half a guided wavelength is placed above the antenna to enhance the isolation between the two PIFAs. The whole antenna structure remains very simple and compact. Good impedance matching and high isolation are obtained in the frequency band of 2.4 -2.484 GHz for IEEE 802.11b/g wireless local area network (WLAN) applications. The details of the antenna design are presented, and simulation and measurement results are also presented and discussed.
TL;DR: A very small-size printed loop antenna for mobile phone application is proposed in this paper, which can generate three resonant modes (0.25, 0.5, and 1.0-wavelength modes) at about 925, 1800, and 2200 MHz.
Abstract: A very-small-size printed loop antenna for mobile phone application is proposed. The antenna has a loop strip of length 62 mm only, which is folded into an L-shape and occupies a small area of 96.5 mm2 on the top no-ground portion of the system circuit board of the mobile phone. By incorporating a simple matching circuit formed by a chip capacitor and a chip inductor, both in series, the loop antenna can generate three resonant modes (0.25-, 0.5-, and 1.0-wavelength modes) at about 925, 1800, and 2200 MHz. The 0.25-wavelength mode forms the antenna's lower band covering GSM operation, whereas the 0.5- and 1.0-wavelength modes form the antenna's upper band covering DCS/PCS/UMTS operation. Quad-band operation is hence obtained for the printed loop antenna, although it has a very small size. Details of the proposed antenna are presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 184–192, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24008
TL;DR: In this article, an inverted truncated annular conical dielectric resonator antenna (DRA) for potential use in body-area network (BAN) applications is introduced.
Abstract: An inverted truncated annular conical dielectric resonator antenna (DRA) for potential use in body-area network (BAN) applications is introduced. The antenna is designed to operate within the lower European ultrawideband (UWB) frequency band (3.4-5.0 GHz). The selected DRA geometry in combination with a capacitively loaded monopole as the feeding mechanism results in a low-profile antenna with wide bandwidth and stable monopole-like patterns. In addition, the antenna exhibits good UWB properties, as characterized through the dispersion effect on the transmitted impulse voltage signal. The DRA has been numerically and experimentally examined for both free-space and on-body applications, demonstrating a good performance in the frequency- and time-domain.
Proceedings Article•
23 Mar 2009TL;DR: In this article, the design procedure of a multimode multiple-input multiple-output (MIMO) antenna is presented, which consists of a metallic ring antenna operating with different orthogonal modes.
Abstract: In this communication, the design procedure of a multimode Multiple-Input Multiple-Output (MIMO) antenna is presented. The antenna consists of a metallic ring antenna operating with different orthogonal modes, whose performance in a MIMO system is similar to traditional antenna arrays. Thus, a compact MIMO antenna is obtained, which is very suitable for mobile terminals. A modal analysis of the antenna is carried out first by means of the Theory of Characteristic Modes, in order to identify the different radiating modes of the antenna. Then a set of feeding configurations is proposed so as to excite these modes. As the modes must operate in the same frequency band, a loading technique is used in the antenna in order to shift the resonance frequency of the modes to the proper band.
TL;DR: In this article, a conformal body-worn antenna for communications at 300 MHz is presented, which consists of a thin broadband flared-dipole element printed on a thin (0.1 mm) FR4 substrate without metallic backing or other shielding.
Abstract: A conformal body-worn antenna is presented for communications at 300 MHz. The antenna consists of a thin broadband flared-dipole element printed on a thin (0.1 mm) FR4 substrate without metallic backing or other shielding. The letter presents the design approach for tuning, matching, and mounting the antenna on the human body. Measurements are given for a human body phantom, and these are compared to simulations. Different antenna positions for improved coverage are also presented.
TL;DR: Differential evolution algorithm is used for the pattern synthesis of planar antenna arrays with prescribed pattern nulls by position-only and position-amplitude optimization.
Abstract: Differential evolution algorithm is used for the pattern synthesis of planar antenna arrays with prescribed pattern nulls by position-only and position-amplitude optimization. The position-only optimization for a planar array allows null synthesis in any prescribed direction. For planar antenna array thinning it is necessary to use position-amplitude optimization for problems involving more than two nulls.
TL;DR: In this article, a frequency-reconfigurable antenna for a mobile phone with small volume is proposed, which consists of a planar inverted F-antenna (PIFA) with volume of 4times36times5timesmm 3 and a monopole antenna embedded in the same space.
Abstract: A frequency-reconfigurable antenna for a mobile phone with small volume is proposed. The proposed antenna consists of a planar inverted F-antenna (PIFA) with volume of 4times36times5timesmm 3 and a monopole antenna embedded in the same space. The two antennas are excited by two separate feeds with a common ground plane. A switch is used in the PIFA for frequency-reconfigurable operation. The PIFA can cover either LTE (698-806-MHz) or GSM900 (880-960-MHz) depending on the state of the switch. The monopole antenna can cover either PCS1900 (1.85-1.99-GHz) and m-WiMAX (3.4-3.8-GHz) or WLAN 802.11a (5.15-5.35-GHz) depending on the state of the switch. The antenna gain is in the range of -1.99-0.61-dBi over 700-MHz-2-GHz bands and 2.39-4.62-dBi over the bands higher than 3-GHz. The proposed antenna is shown to have good radiation characteristics.
TL;DR: A practical design for a Landstorfer planar antenna that can be implemented as a compact and low cost reconfigurable planar antennas array that can have 360-degree coverage in azimuth and allows a wide variety of directive beams to be electronically selected.
Abstract: In this paper, we introduce a practical design for a Landstorfer planar antenna that can be implemented as a compact and low cost reconfigurable planar antenna array. The array, we propose, can have 360-degree coverage in azimuth and allows a wide variety of directive beams to be electronically selected while maintaining a simple structure, ease of manufacture and low cost with high efficiency. One of the possible applications for this array is in WLAN systems where high gain and low cost adaptable antennas promise increases in capacity and coverage. The array design utilizes key innovations in the design of Landstorfer antennas and feed/switching network. The Landstorfer antenna exhibits a high gain with 9.5 dBi and low mutual coupling between elements. A proposed reflector for the Landstorfer antenna is implemented and it allows the antenna array to be fabricated on a 2-layer PCB board. We also present a low cost feed/switching network which allows flexible control of the antenna patterns. The design makes use of PIN diodes as switching elements and a resonant inductor to improve the isolation of the PIN diodes. By integrating the antenna elements, feed/switching network and array configuration, a low cost reconfigurable Landstorfer planar array can be formed.
TL;DR: In this article, a simple electromagnetically coupled wideband printed microstrip antenna having a 2:1 VSWR bandwidth of 38% covering the 5.2/5.8-GHz WLAN, HIPERLAN2, and HiSWANa communication bands is presented.
Abstract: A simple electromagnetically coupled wideband printed microstrip antenna having a 2:1 VSWR bandwidth of 38% covering the 5.2/5.8-GHz WLAN, HIPERLAN2, and HiSWANa communication bands is presented. The large bandwidth is obtained by adding a rectangular metal strip on a slotted square microstrip antenna. The antenna occupies an overall dimension of 42 times 55 times 3.2 mm3 when printed on a substrate of dielectric constant 4. It exhibits good radiation characteristics and moderate gain in the entire operating band. Details of the design along with experimental and simulation results are presented and discussed.
Patent•
16 Nov 2009TL;DR: In this paper, a simple, compact multi-band PIFA including two arm portions, where one arm portion is grounded at two points to form a loop, a ground plane, and a plastic carrier and housing, is presented.
Abstract: A simple, compact multi-band PIFA including two arm portions, where one arm portion is grounded at two points to form a loop, a ground plane, and a plastic carrier and housing. The antenna radiates a same signal from both arm portions, at different efficiencies according to the radiated frequency and the effective length of each arm. The antenna is made from a single standard metal sheet by cutting it and is assembled with the metal ground plane and the other plastic parts. In one embodiment, the antenna is folded into a 3D U-shape to reduce its size for use in mobile communication devices. In another embodiment, the antenna is a penta-band antenna with return loss of -6B or better and measures 40 x 8 x 8 mm or smaller.
26 May 2009
TL;DR: In this article, several issues regarding the magneto-dielectrics and their application to the antenna miniaturization are investigated and a characterization methodology to extract the frequency dependent properties (∊′, ∊″ µ′, and µ″) of these materials is presented.
Abstract: Effective antenna miniaturization is a challenging problem due to the inevitable trade-off between the size and the performance of the antenna due to the fact that antenna performance is bound with the fundamental limits based on the size of the antenna. Antenna miniaturization is also a critical issue since the key component determining the size of a mobile device is usually the antenna. Recent studies on novel materials called magneto-dielectrics have raised hope to miniaturize the antenna effectively. Magneto-dielectrics are materials with both the relative permittivity (∊ r ) and the relative permeability (µ r ) of the substrate greater than unity. In this paper, several issues regarding the magneto-dielectrics and their application to the antenna miniaturization are investigated. The theoretical reason why the magneto-dielectrics are better substrates for planar antennas than the dielectric materials is investigated along with a material synthesis technique to explain how to realize these materials. Additionally, a characterization methodology to extract the frequency dependent properties (∊′, ∊″ µ′, and µ″) of these materials is presented in this paper. Finally, the advantages and the limitations of these substrates for antenna applications are discussed in the paper.
TL;DR: In this article, a planar microstrip antenna array with a Butler matrix has been implemented to form a microstrip array that has narrow beamwidth, circular polarization, and polarization diversity.
Abstract: A planar microstrip antenna array with a Butler matrix has been implemented to form a microstrip antenna array that has narrow beamwidth, circular polarization, and polarization diversity. This microstrip antenna array improves the system performance in indoor wireless dynamic environments. A circularly polarized microstrip antenna array is designed such that it consists of four identical linearly polarized patches. A 2 times 2 planar microstrip antenna array and a 4 times 4 Butler matrix have been designed and simulated using advanced design system and Matlab software. The measured results show that a combination of a planar microstrip antenna array and a 4 times 4 Butler matrix creates four beams; two of these beams have right-hand circular polarization and the other two have left-hand circular polarization.