Showing papers on "Patch antenna published in 2009"

Dual-Band Wearable Textile Antenna on an EBG Substrate

Abstract: Performance of a dual-band coplanar patch antenna integrated with an electromagnetic band gap substrate is described. The antenna structure is made from common clothing fabrics and operates at the 2.45 and 5 GHz wireless bands. The design of the coplanar antenna, band gap substrate, and their integration is presented. The band gap array consists of just 3 times 3 elements but reduces radiation into the body by over 10 dB and improves the antenna gain by 3 dB. The performance of the antenna under bending conditions and when placed on the human body are presented.

Method and apparatus for adaptive tuning of wireless power transfer

Abstract: Exemplary embodiments are directed to wireless power transfer. A transmit antenna generates an electromagnetic field at a resonant frequency of to create a coupling-mode region within a near field of the transmit antenna. A receive antenna receives the resonant frequency when it is within the coupling-mode region and resonates substantially near the resonant frequency. One, or both, of the transmit and receive antennas are tunable antennas that can be adaptively tuned. The adaptive tuning is accomplished by detecting a mismatch at the tunable antenna and generating a mismatch signal responsive to a voltage standing wave ratio at the tunable antenna. A resonance characteristic of the tunable antenna can be modified by adjusting a capacitance of a variable capacitor network connected to the tunable antenna.

Antennas for Over-Body-Surface Communication at 2.45 GHz

Abstract: In this paper, the on-body performance of a range of wearable antennas was investigated by measuring |S 21| path gain between two devices mounted on tissue-equivalent numerical and experimental phantoms, representative of human muscle tissue at 2.45 GHz. In particular, the study focused on the performance of a compact higher mode microstrip patch antenna (HMMPA) with a profile as low as lambda/20. The 5- and 10-mm-high HMMPA prototypes had an impedance bandwidth of 6.7% and 8.6%, respectively, sufficient for the operating requirements of the 2.45-GHz industrial, scientific, and medical (ISM) band and both antennas offered 11-dB higher path gain compared to a fundamental-mode microstrip patch antenna. It was also demonstrated that a 7-dB improvement in path gain can be obtained for a fundamental-mode patch through the addition of a shortening wall. Notably, on-body HMMPA performance was comparable to a quarter wave monopole antenna on the same size of groundplane, mounted normal to the tissue surface, indicating that the low-profile and physically more robust antenna is a promising solution for bodyworn antenna applications.

A 77-GHz FMCW MIMO Radar Based on an SiGe Single-Chip Transceiver

Abstract: This paper describes a novel frequency-modulated continuous-wave radar concept, where methods like nonuniform sparse antenna arrays and multiple-input multiple-output techniques are used to improve the angular resolution of the proposed system. To demonstrate the practical feasibility using standard production techniques, a prototype sensor using a novel four-channel single-chip radar transceiver in combination with differential patch antenna arrays was realized on off-the-shelf RF substrate. Furthermore, to demonstrate its practical applicability, the assembled system was tested in real world measurement scenarios in conjunction with the presented efficient signal processing algorithms.

A Universal UHF RFID Reader Antenna

Abstract: A broadband circularly polarized patch antenna is proposed for universal ultra-high-frequency (UHF) RF identification (RFID) applications. The antenna is composed of two corner-truncated patches and a suspended microstrip line with open-circuited termination. The main patch is fed by four probes which are sequentially connected to the suspended microstrip feed line. The measurement shows that the antenna achieves a return loss of -15 dB, gain of 8.3 dBic, axial ratio (AR) of 3 dB, and 3-dB AR beamwidth of 75deg over the UHF band of 818-964 MHz or 16.4%. Therefore, the proposed antenna is universal for UHF RFID applications worldwide at the UHF band of 840-960 MHz. In addition, a parametric study is conducted to facilitate the design and optimization processes for engineers.

Small Square Monopole Antenna With Inverted T-Shaped Notch in the Ground Plane for UWB Application

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.

Meshed Patch Antennas Integrated on Solar Cells

Abstract: This letter presents the study of integrating meshed patch antennas directly onto the solar cells of a small satellite to save valuable surface real estate. The cover glass of the solar cell is used as the substrate for the antennas. The integrated patch antennas are designed to have sufficient optical transparency to ensure the proper functionality of the solar cells. A prototype meshed patch antenna is designed and integrated on after-market solar cells. The antenna has an optical transparency of 93%, and the measurements agree well with the design.

A Compact Transmission-Line Metamaterial Antenna With Extended Bandwidth

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.

A Broadband Center-Fed Circular Patch-Ring Antenna With a Monopole Like Radiation Pattern

Abstract: A center-fed circular microstrip patch antenna with a coupled annular ring is presented. This antenna has a low profile configuration with a monopole like radiation pattern. Compared to the center-fed circular patch antenna (CPA), the proposed antenna has a large bandwidth and similar radiation pattern. The proposed antenna is fabricated and tested. It resonates at 5.8 GHz, the corresponding impedance bandwidth and gain are 12.8% and 5.7 dBi, respectively. Very good agreement between the measurement and simulation for the return loss and radiation patterns is achieved.

Microstrip and printed antenna design

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.

An Ultrawideband Diversity 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.

Novel Planar UWB Monopole Antenna With Triple Band-Notched Characteristics

Abstract: A novel spade-shaped ultrawideband (UWB) printed planar monopole antenna with triple band-notched characteristics is proposed. By employing a hook-shaped defected ground structure (DGS) in each side of the ground plane, embedding an Omega-shaped slot on the radiating patch as well as adding a semi-octagon-shaped resonant ring on the back side of the antenna, triple notched frequency bands are achieved. The proposed antenna has been successfully simulated, fabricated, and measured. Effects of the key parameters on the frequency ranges of the notched bands are also investigated. The measured impedance bandwidth defined by VS WR < 2 of 10.1 GHz (2.9-13 GHz), with the triple notched bands of 3.3-3.9, 5.2-5.35, and 5.8-6.0 GHz, is obtained. Measured group delay and transmission characteristics indicate that the antenna has good transient response. Furthermore, the proposed antenna shows the merit of insensitivity to both finite ground size and fabrication tolerances.

Broadband Circularly Polarized Annular-Ring Microstrip Antenna

Abstract: A wideband circularly polarized (CP) annular-ring patch antenna with two proximity-coupled L-probe feeds orientated to have phases of 0deg and 90deg, using a broadband 90deg hybrid feed, is proposed. It is found that the current distribution for CP operation can be improved by cutting a smaller concentric circular slot on the original larger circular patch to form an annular-ring patch. With such an arrangement, the proposed antenna delivers a wider axial ratio (AR) bandwidth than that of the conventional circular patch with the identical feeding technique. Considering the common overlapped bandwidth limited by the impedance, AR and gain, the proposed annular-ring patch antenna exhibits an effective bandwidth of 38% from 1.5 to 2.2 GHz, which is wider than the corresponding bandwidth of 29.7% from 1.35 to 1.82 GHz for the conventional circular patch. Moreover, the effective bandwidth of 38% for the proposed annular-ring antenna is also much wider than those for the other annular-ring patch antennas in the literature.

Small Square Monopole Antenna for UWB Applications With Variable Frequency Band-Notch Function

Abstract: In this letter, a novel printed monopole antenna (PMA) for ultrawideband (UWB) applications with variable frequency band-notch characteristic is presented. The proposed antenna consists of a stepped square radiating patch with two U-shaped slots and a notched ground plane with a T-shaped sleeve that provides a wide usable fractional bandwidth of more than 140% (2.8516.73 GHz). By cutting two modified U-shaped slots with variable dimensions on the radiating patch, frequency band-stop performance is generated, and we can control its characteristics such as band-notch frequency and its bandwidth. The designed antenna has a small size of 12 times 19 mm2 while showing the band rejection performance in the frequency band of 5.02-5.97 GHz.

High-Efficient and High-Gain Superstrate Antenna for 60-GHz Indoor Communication

Abstract: A high-efficient and high-gain aperture coupled patch antenna with superstrate at 60 GHz is studied and presented. It is noted that adding superstrate will result in a significant effect on the antenna performances, and the size of the superstrate is critical for the optimum performance. The maximum measured gain of a single antenna with superstrate is 14.6 dBi, which is higher than that of a classical 2 x 2 array. It is found that the gain measured of a single antenna with superstrate increases nearly 9 dB at 60 GHz over its basic patch antenna. This superstrate antenna gives a very high estimated efficiency of 76%. The 2:1 measured VSWR bandwidth with superstrate is 6.8%. The radiation patterns are found to be broadside all over the frequency band. Also, this letter explains a comparison to another source of parasitic patch superstrate antenna with normal microstrip coupling. It is found that aperture coupling is better for high-gain antenna applications.

Foldable and Stretchable Liquid Metal Planar Inverted Cone Antenna

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.

A Dual-Band Circularly Polarized Stub Loaded Microstrip Patch Antenna for GPS Applications

Abstract: A single-feed low-profile and easy to fabricate circularly polarized microstrip patch antenna has been developed for GPS applications. For dual frequency operation, four slots are etched near edges of the patch and a crossed slot etched in the center for generating circular polarization. In order to reducing the frequency ratio of two frequency bands of the antenna, the patch is loaded by four short circuit microstrip stubs. The paper reports several simulation results that confirm the desired characteristics of the antenna. Using stub loading, the frequency ratio of two bands of the antenna can be, even, reduced to 1.1.

An Integrated Approach to RF Antenna-Filter Co-Design

Abstract: In this letter, a co-designed antenna-filter is presented. The antenna-filter is composed of a microstrip patch antenna and a hairpin filter, both of which share the same ground plane to reduce the size. Instead of using the traditional 50-Omega interfaces, the impedance between the filter and antenna is optimized to improve the performance. The simulated and measured results have demonstrated that co-designed antenna-filter has a better bandwidth (4.7%, 4.064.26 GHz) and a larger gain (4.3 dBi) than the traditional version with 50-Omega interfaces impedance.

A Novel Compact Ultra-Wideband (UWB) Wide Slot Antenna with via Holes

Abstract: A novel compact ultra-wideband (UWB) wide slot antenna with via holes is presented for UWB applications. The antenna is composed of a trapezoidal slot on the ground plane, a rectangular patch in the center of the slot and three via holes connecting the rectangular patch and the microstrip feed-line. The antenna is successfully designed, implemented, and measured. The measured results show that the proposed antenna with compact size of 27:0mm£29:0mm£1:0mm achieves good performance, such as an impedance matching bandwidth of 111.7% (jS11j • i10dB), constant gain and stable radiation patterns over its whole frequency range.

Broadband Microstrip Antenna With Left-Handed Metamaterials

Abstract: A novel type of microstrip antenna is proposed for compact wideband wireless applications. The antenna is composed of six unit cells of left-handed metamaterial (LHM) and a dipole element. The dipole is directly connected to three of six LHM unit cells, which are arranged in a 2 times 3 antenna array form. In this aspect, the proposed antenna is regarded as LHM loaded dipole antenna. The antenna is matched with a stepped impedance transformer and rectangular slot in the truncated ground plane. The coupled LH resonances and simultaneous excitation of different sections of unit cells and dipole result into broad bandwidth. The proposed antenna has a maximum gain of -1 dBi at 2.5 GHz. The measured return loss indicates 63% bandwidth for |S11| < -10 dB over the band of 1.3-2.5 GHz. The overall size of LHM loaded antenna is lambda0/2.87 times lambda0/11.27 times lambda0/315.80 at the center frequency. The radiation of the electrically small LHM unit cells is also demonstrated by the simulated radiation pattern, which is an important concept for the antenna miniaturization.

Resonator for wireless power transmission

Abstract: Disclosed is a resonator for wireless power transmission used in a mobile device. The resonator includes a substrate, at least one microstrip line, and a magnetic core. The microstrip line is formed on the substrate and is provided at one side thereof with a slit to have an open-loop shape. The magnetic core is formed on the substrate and is disposed on a space defined by the microstrip line to increase coupling strength.

Compact triple band antenna for WLAN/ WiMAX applications

Abstract: A low profile printed antenna with triple band operation is presented for simultaneous use in wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) applications. The antenna consists of a rectangular radiating element fed asymmetrically by a 50 Ω microstrip line and a shaped trapezoidal ground plane. Rectangular horizontal strips are attached to the radiation element to form different current paths which make the antenna resonate in WLAN and WiMAX frequency bands. The antenna operates in dipole configuration outlining overall dimensions of 38×30×0.8 mm3.

Multiband Printed Monopole Slot Antenna for WWAN Operation in the Laptop Computer

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.

Integrated Bluetooth and UWB Antenna

Abstract: A small-sized, low-profile, and planar integrated Bluetooth and ultrawideband (UWB) antenna is presented. The antenna exhibits a dual-band operation covering 2400-2484 MHz (Bluetooth) and 3100-10600 MHz (UWB) frequency bands. It is fed by a microstrip line and built on a FR-4 substrate with 42times46 mm2 surface area. The impedance, radiation, phase linearity, and impulse response properties of the antenna are studied both theoretically and experimentally. The calculated and measured results agree well. The antenna shows acceptable gain flatness with stable omnidirectional radiation patterns across the integrated Bluetooth and UWB bands. The average group delay is approximately 0.2 ns across UWB frequencies. The impulse response is very good, with some level of ringing observed.

Dual-Feed Dual-Polarized Patch Antenna With Low Cross Polarization and High Isolation

Abstract: In this communication, a dual-feed dual-polarized microstrip antenna with low cross polarization and high isolation is experimentally studied. Two different feed mechanisms are designed to excite a dual orthogonal linearly polarized mode from a single radiating patch. One of the two modes is excited by an aperture-coupled feed, which comprises a compact resonant annular-ring slot and a T-shaped microstrip feedline; while the other is excited by a pair of meandering strips with a 180 $^{\circ}$ phase differences. Both linearly polarized modes are designed to operate at 2400-MHz frequency band, and from the measured results, it is found that the isolation between the two feeding ports is less than 40 dB across a 10-dB input-impedance bandwidth of 14%. In addition, low cross polarization is observed from the radiation patterns of the two modes, especially at the broadside direction. Simulation analyses are also carried out to support the measured results.

A Novel High-Directivity Microstrip Patch Antenna Based on Zero-Index Metamaterial

Abstract: In this letter, a novel high-directivity microstrip patch antenna (MPA) based on planar zero-index metamaterials is presented. An averaging effect over the metamaterial structure yields an effective permittivity that approaches zero at 8.75 GHz, which results in a metamaterial with zero index of refraction. Both the simulation and experimental results show that the directivity of the antenna is effectively enhanced based on the zero refraction characteristics of the metamaterial.

Enhanced-Gain Microstrip Antenna Using Engineered Magnetic Superstrates

Abstract: This letter presents a novel engineered magnetic superstrate designed to enhance the gain and efficiency of a microstrip patch antenna without any substantial increase in the profile of the whole structure (the antenna with the superstrate). The modified split ring resonator (MSRR) inclusions are used in the design of the engineered magnetic superstrate. Numerical full-wave simulations as well as analytical models are used to analyze the entire radiating system. Considering as an example a microstrip antenna operating within the UMTS band, the broadside gain of the antenna was improved by 3.4 dB and the efficiency was improved by 17% when using the engineered superstrate. The total height of the proposed structure, antenna with superstrate, is lambda0/7, where lambda0 is the free-space wavelength at the resonance frequency of the antenna.

Microstrip Antenna's Gain Enhancement Using Left-Handed Metamaterial Structure

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.

Broadband E-h Shaped Microstrip Patch Antenna for Wireless Systems

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.

Wireless antenna for emitting conical radiation

Abstract: An antenna described herein includes a driven patch that is configured to emit radiation in a broadside direction in response to receiving excitation current, wherein the driven patch has a first radiating edge and a second radiating edge that are approximately parallel to one another. The antenna also includes a reflector element that is configured to reflect radiation emitted from the first radiating edge in a quasi-endfire direction. The antenna can also include two director elements that are configured to direct radiation emitted from the second radiating edge of the driven patch in a quasi-endfire direction.