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Journal ArticleDOI

A capacitively loaded PIFA for compact mobile telephone handsets

TL;DR: In this article, a capacitively loaded planar inverted-F antenna (PIFA) was proposed and studied, and it was found that the capacitive load reduced the resonance length of the PIFA from /spl lambda/4 to less than /spl ε/S.
Abstract: A capacitively loaded planar inverted-F antenna (PIFA) is proposed and studied. It is found that the capacitive load reduces the resonance length of the PIFA from /spl lambda//4 to less than /spl lambda//S. A design with a bandwidth of 178 MHz centered at 1.8 GHz is provided to demonstrate that compact antennas for mobile telephone handsets can be constructed using this approach. The finite-difference time-domain (FDTD) method is used in the study and experimental verification is also provided.

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Citations
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Book
15 Jan 2002
TL;DR: In this paper, the authors present an overview of the most recent advances in regular-size Dual-Frequency Antennas and their application in a wide range of applications, including: 1.1 Introduction.
Abstract: Preface. 1. Introduction and Overview. 1.1 Introduction. 1.2 Compact Microstrip Antennas. 1.3 Compact Broadband Microstrip Antennas. 1.4 Compact Dual-Frequency Microstrip Antennas. 1.5 Compact Dual-Polarized Microstrip Antennas. 1.6 Compact Circularly Polarized Microstrip Antennas. 1.7 Compact Microstrip Antennas with Enhanced Gain. 1.8 Broadband Microstrip Antennas. 1.9 Broadband Dual-Frequency and Dual-Polarized Microstrip Antennas. 1.10 Broadband and Dual-Band Circularly Polarized Microstrip Antennas. 2. Compact Microstrip Antennas. 2.1 Introduction. 2.2 Use of a Shorted Patch with a Thin Dielectric Substrate. 2.3 Use of a Meandered Patch. 2.4 Use of a Meandered Ground Plane. 2.5 Use of a Planar Inverted-L Patch. 2.6 Use of an Inverted U-Shaped or Folded Patch. 3. Compact Broadband Microstrip Antennas. 3.1 Introduction. 3.2 Use of a Shorted Patch with a Thick Air Substrate. 3.3 Use of Stacked Shorted Patches. 3.4 Use of Chip-Resistor and Chip-Capacitor Loading Technique. 3.5 Use of a Slot-Loading Technique. 3.6 Use of a Slotted Ground Plane. 4. Compact Dual-Frequency and Dual-Polarized Microstrip Antennas. 4.1 Introduction. 4.2 Some Recent Advances in Regular-Size Dual-Frequency Designs. 4.3 Compact Dual-Frequency Operation with Same Polarization Planes. 4.4 Compact Dual-Frequency Operation. 4.5 Dual-Band or Triple-Band PIFA. 4.6 Compact Dual-Polarized Designs. 5. Compact Circularly Polarized Microstrip Antennas. 5.1 Introduction. 5.2 Designs with a Cross-Slot of Unequal Arm Lengths. 5.3 Designs with a Y-Shaped Slot of Unequal Arm Lengths. 5.4 Designs with Slits. 5.5 Designs with Spur Lines. 5.6 Designs with Truncated Corners. 5.7 Designs with Peripheral Cuts. 5.8 Designs with a Tuning Stub. 5.9 Designs with a Bent Tuning Stub. 5.10 Compact CP Designs with an Inset Microstrip-Line Feed. 6. Compact Microstrip Antennas with Enhanced Gain. 6.1 Introduction. 6.2 Compact Microstrip Antennas with High-Permittivity Superstrate. 6.3 Compact Microstrip Antennas with Active Circuitry. 7. Broadband Microstrip Antennas. 7.1 Introduction. 7.2 Use of Additional Microstrip Resonators. 7.3 Microstrip Antennas with an Air Substrate. 7.4 Broadband Slot-Loaded Microstrip Antennas. 7.5 Broadband Microstrip Antennas with an Integrated Reactive Loading. 7.6 Broadband Microstrip Antennas with Reduced Cross-Polarization Radiation. 8. Broadband Dual-Frequency and Dual-Polarized Microstrip Antennas. 8.1 Introduction. 8.2 Broadband Dual-Frequency Microstrip Antennas. 8.3 Broadband Dual-Polarized Microstrip Antennas. 9. Broadband and Dual-Band Circularly Polarized Microstrip Antennas. 9.1 Introduction. 9.2 Broadband Single-Feed Circularly Polarized Microstrip Antennas. 9.3 Broadband Two-Feed Circularly Polarized Microstrip Antennas. 9.4 Broadband Four-Feed Circularly Polarized Microstrip Antennas. 9.5 Dual-Band Circularly Polarized Microstrip Antennas. Index.

1,734 citations

Journal ArticleDOI
TL;DR: In this article, a simple ground plane structure that can reduce mutual coupling between closely packed antenna elements is proposed and studied, which consists of a slitted pattern, without via's, etched onto a single ground plane and it is therefore low cost and straightforward to fabricate.
Abstract: A simple ground plane structure that can reduce mutual coupling between closely-packed antenna elements is proposed and studied. The structure consists of a slitted pattern, without via's, etched onto a single ground plane and it is therefore low cost and straightforward to fabricate. It is found that isolations of more than -20 dB can be achieved between two parallel individual planar inverted-F antennas (PIFAs) sharing a common ground plane, with inter-antenna spacing (center to center) of 0.116 lambdao and ground plane size 0.331lambdao 2. At 2.31 GHz it is demonstrated that this translates into an edge to edge separation between antennas of just 10 mm. Similarly the structure can be applied to reduce mutual coupling between three or four radiating elements. In addition the mutual coupling between half wavelength patches and monopoles can also be reduced with the aid of the proposed ground plane structure. Results of parametric studies are also given in this paper. Both simulation and measurement results are used to confirm the suppression of mutual coupling between closely-packed antenna elements with our slitted ground plane.

586 citations


Cites background from "A capacitively loaded PIFA for comp..."

  • ...For example in [2] it is stated that no matter how two PIFAs [3], [4] are oriented either collinear, orthogonal or parallel above a single ground plane with air substrate, the inter-element spacing should be at least greater than 0....

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Journal ArticleDOI
TL;DR: In this paper, the performance of the mobile phone handset antenna-chassis combination is analyzed based on an approximate decomposition of the waves on the structure into two resonant wavemodes: the antenna-element wavemode and the chassis wavemode.
Abstract: The performance of the mobile phone handset antenna-chassis combination is analyzed based on an approximate decomposition of the waves on the structure into two resonant wavemodes: the antenna-element wavemode and the chassis wavemode. A double resonator equivalent circuit model is presented and used to estimate the impedance bandwidth and the respective distributions of radiation losses with typical parameter values at 900 and 1800 MHz. It is noticed that at 900 MHz, the radiation losses of the antenna element wavemode represent typically less than 10% of the total power. Thus, the antenna element works mainly as a matching element, which couples to the low-Q resonant wavemode of the chassis. At 1800 MHz, the contribution of the antenna element wavemode is larger. By enhancing the coupling and by tuning the chassis resonance, it is possible to obtain an impedance bandwidth of over 50% (6 dB return loss) at both at 900 and 1800 MHz. The results given by the equivalent circuit study are fully supported by those of three-dimensional phone-model simulations, including calculation of the SAR and efficiency values. In prototyping, the 6 dB bandwidth of 5.5% was obtained at 980 MHz with a nonradiating coupling element with a volume of 1.6 cm/sup 3/ on a 120 mm long chassis.

500 citations


Cites background or methods from "A capacitively loaded PIFA for comp..."

  • ...effect of the chassis is usually not analyzed, though in many published small-antenna designs the antenna is mounted on a phone chassis and from the large bandwidths obtained it can be assumed that the effect of the chassis is significant [4], [8]–[12]....

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  • ...The resonant frequency of the antenna element can be tuned rather simply to the required frequency of operation (often, however, at the expense of ) by using methods like dielectric or reactive loading or meandering [8], [10], [12], [18], and [24]....

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Journal ArticleDOI
TL;DR: In this paper, a USB dongle MIMO antenna for the 2.4 GHz WLAN band is presented, which consists of two antenna elements and a coupling element which artificially creates an additional coupling path between the antenna elements.
Abstract: This paper introduces a coupling element to enhance the isolation between two closely packed antennas operating at the same frequency band. The proposed structure consists of two antenna elements and a coupling element which is located in between the two antenna elements. The idea is to use field cancellation to enhance isolation by putting a coupling element which artificially creates an additional coupling path between the antenna elements. To validate the idea, a design for a USB dongle MIMO antenna for the 2.4 GHz WLAN band is presented. In this design, the antenna elements are etched on a compact low-cost FR4 PCB board with dimensions of 20times40times1.6 mm3. According to our measurement results, we can achieve more than 30 dB isolation between the antenna elements even though the two parallel individual planar inverted F antenna (PIFA) in the design share a solid ground plane with inter-antenna spacing (Center to Center) of less than 0.095 lambdao or edge to edge separations of just 3.6 mm (0.0294 lambdao). Both simulation and measurement results are used to confirm the antenna isolation and performance. The method can also be applied to different types of antennas such as non-planar antennas. Parametric studies and current distribution for the design are also included to show how to tune the structure and control the isolation.

413 citations


Cites background from "A capacitively loaded PIFA for comp..."

  • ...It can be seen that two identical PIFA [6], [19] antenna elements are integrated on a low cost FR4 substrate with a PCB thickness of 1....

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  • ...space wavelength in order to achieve approximately 20 dB isolation or more [4]–[6]....

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Journal ArticleDOI
TL;DR: In this article, several electrically small resonant antennas employing the composite right/left-handed transmission line (CRLH-TL) are presented for integration with portable RF modules.
Abstract: Several electrically small resonant antennas employing the composite right/left-handed transmission line (CRLH-TL) are presented for integration with portable RF modules. The proposed antenna designs are based on the unique property of anti-parallel phase and group velocity of the CRLH-TL at its fundamental mode. In this mode, the propagation constant increases as the frequency decreases, therefore, a small guided wavelength can be obtained at a lower frequency to provide the small lambdag/2 resonant length used to realize a compact antenna design. Furthermore, the physical size and the operational frequency of the antenna depend on the unit cell size and the equivalent transmission line model parameters of the CRLH-TL, including series inductance, series capacitance, shunt inductance and shunt capacitance. Optimization of these parameters as well as miniaturization techniques of the physical size of unit cell is investigated. A four unit-cell resonant antenna is designed and tested at 1.06 GHz. The length, width and height of the proposed antenna are 1/19lambda0, 1/23lambda0 and 1/83lambda0, respectively. In addition, a compact antenna using a 2-D three by three mushroom like unit cell arrangement is developed at 1.17 GHz, showing that an increased gain of 0.6 dB and higher radiation efficiency can be achieved over the first prototype antenna. The same design is applied in the development of a circularly polarized antenna operating at 2.46 GHz. A 116deg beamwidth with axial ratio better than 3 dB is observed. The physical size of the proposed mushroom type small antenna and the circularly polarized antenna is 1/14lambda0 by 1/14lambda0 by 1/39lambda0 and 1/10lambda0 by 1/10lambda 0 by 1/36lambda0, respectively

341 citations


Cites methods from "A capacitively loaded PIFA for comp..."

  • ...The PIFA size can be reduced by several methods such as using a capacitive load or increasing the current flowing path [8], [9]....

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References
More filters
Journal ArticleDOI
Abstract: Maxwell's equations are replaced by a set of finite difference equations. It is shown that if one chooses the field points appropriately, the set of finite difference equations is applicable for a boundary condition involving perfectly conducting surfaces. An example is given of the scattering of an electromagnetic pulse by a perfectly conducting cylinder.

14,070 citations

Book
04 May 2018
TL;DR: In this paper, the authors define the fundamental concepts of scattered field FDTD and its application in a wide range of applications including: Coupling Effects Coupling effects Waveguide Aperture Coupling Lossy Dielectric Scattering Special Capabilities Far Zone Transformation Frequency Dependent Materials Surface Impedance Subcellular Extensions Nonlinear Loads and Materials Visualization Advanced Applications Far Zone Scattering Antennas Gyrotropic Media Mathematical Basis of FDTD, and Alternate Methods Difference Equations in General Stability, Dispersion, Accuracy Outer Radiation Boundary Conditions Alternate Formulations
Abstract: Fundamental Concepts Scattered Field FDTD Formulation FDTD Basics Basic Applications Coupling Effects Waveguide Aperture Coupling Lossy Dielectric Scattering Special Capabilities Far Zone Transformation Frequency Dependent Materials Surface Impedance Subcellular Extensions Nonlinear Loads and Materials Visualization Advanced Applications Far Zone Scattering Antennas Gyrotropic Media Mathematical Basis of FDTD and Alternate Methods Difference Equations in General Stability, Dispersion, Accuracy Outer Radiation Boundary Conditions Alternate Formulations Appendix A: Other Coordinate Systems and Reduced Dimensions Appendix B: FORTRAN Listings

2,266 citations

Book
01 Jan 1961
TL;DR: In this paper, the authors present an overview of the fundamental principles of Antennas, including antennas of Discrete Elements (DDE), dipoles, monopoles, and loops.
Abstract: Introduction to Antennas.Fundamentals of Antennas.Arrays of Discrete Elements.Dipoles and Monopoles.Loop Antennas.Small Antennas.Microstrip Antennas.Slot Antennas.Slot-Antenna Arrays.Leaky-Wave Antennas.Long-Wire Antennas.Surface-Wave Antennas and Surface-Wave Excited Arrays.Helical Antennas.Frequency-Independent Antennas.Horn Antennas.Lens Antennas.Reflector Antennas.Feeds for Lenses and Reflectors.Electromechanical Scanning Antennas.Frequency-Scan Antennas.Phased Arrays.Conformal and Low-Profile Arrays.Adaptive Antennas.Methods of Polarization Synthesis.Low-Frequency Antennas.Medium-Frequency Broadcast Antennas.High-Frequency Antennas.VHF and UHF Communications Antennas.TV and FM Transmitting Antennas.TV Receiving Antennas.Microwave-Relay Antennas, Radiometer Antennas.Radar Antennas.Microwave Beacon Antennas.Tracking Antennas.Satellite Antennas.Earth Station Antennas.Aircraft Antennas.Seeker Antennas.Direction-Finding Antennas and Systems.ECM and ESM Antennas.Radio-Telescope Antennas.Transmission Lines and Waveguide.Impedance Matching and Broadbanding.Radomes.Microwave Propagation.Antenna Measurements.Materials and Design Data.

1,761 citations

Book
01 Jan 1992
TL;DR: System architects involved in the design of personal communications systems will find the book to be a complete description of the GSM communications system, and it may serve as a general introduction to digital cellular systems.
Abstract: From the Publisher: This book is out-of-print, and a new second edition will be released by the end of 2002. The digital standard known as the Global System for Mobile (GSM) has captured a large share of the global cellular market. This book aims to bridge the gap between a reader’s basic knowledge of telecommunications and the complexities of the 5000-page GSM technical specification. It describes the system as a whole, covering all aspects of the standard, including mobile stations, switching equipment, the radio interface, infrastructure, transmission methods, and signaling protocols. System architects involved in the design of personal communications systems will find the book to be a complete description of the GSM communications system. It also may serve as a general introduction to digital cellular systems.

1,502 citations

Journal ArticleDOI
TL;DR: The paper presents the analysis of small antennas mounted on hand-held transceivers using the finite-difference time-domain (FDTD) method, which is used to predict the gain patterns and broadband input impedance behavior of monopole, planar inverted F, and loop antenna elements mounted on the handset.
Abstract: The design of antennas for hand-held communications devices depends on the implementation of simulation tools that can accurately model general topologies. The paper presents the analysis of small antennas mounted on hand-held transceivers using the finite-difference time-domain (FDTD) method. The key features of the FDTD implementation are discussed, with particular emphasis placed upon modeling of the source region. The technique is used to predict the gain patterns and broadband input impedance behavior of monopole, planar inverted F, and loop antenna elements mounted on the handset. Effects of the conducting handset chassis, the plastic casing around the device, and lumped elements integrated into the antenna design are illustrated. Experimental results are provided to verify the accuracy of the computational methodology. The concept of antenna diversity is discussed, and key assumptions and expressions are provided that characterize the multipath fading fields. Several computational examples demonstrate the diversity performance of two receiving antennas on a single handset. >

313 citations

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What is a telephone handset amplifier?

A design with a bandwidth of 178 MHz centered at 1.8 GHz is provided to demonstrate that compact antennas for mobile telephone handsets can be constructed using this approach.