Showing papers on "Coaxial antenna published in 2012"

Printed MIMO-Antenna System Using Neutralization-Line Technique for Wireless USB-Dongle Applications

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

Package structures to improve on-chip antenna performance

Abstract: A radio frequency integrated circuit (RFIC) chip package is provided having an RFIC chip and an integrated antenna structure. The integrated antenna structure includes an on-chip antenna having one or more radiator elements formed as part of a back-end-of-line structure of the RFIC chip. The antenna structure further includes a superstrate structure disposed on the back-end-of-line structure of the RFIC chip. The superstrate structure includes at least one substrate layer and a focusing metal element. The focusing metal element has a structure that is complementary to the on-chip radiator elements and which is configured to focus electromagnetic radiation to and from the planar antenna structure. The superstrate structure improves the performance (e.g., antenna gain and bandwidth) of the on-chip antennas for millimeter-wave applications.

The Magnetoelectric Dipole—A Wideband Antenna for Base Stations in Mobile Communications

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

Modular antenna array with rf and baseband beamforming

Abstract: Generally, this disclosure provides systems and methods for a modular antenna array using radio frequency (RF) and baseband (BB) beamforming. A system may include a plurality of antenna modules, each of the antenna modules further including an array of antenna elements coupled to an RF beamforming circuit, the RF beamforming circuit to adjust phase shifts associated with the antenna elements to generate an antenna beam associated with the antenna module; and a central beamforming module coupled to each of the antenna modules, the central beamforming module to control the antenna beam associated with each of the antenna modules and to generate signal adjustments relative to each of the antenna modules, wherein the arrays of antenna elements of the antenna modules combine to operate as a composite antenna beamforming array.

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

Abstract: A coax-feed wideband dual-polarized patch antenna with low cross polarization and high port isolation is presented in this letter. The proposed antenna contains two pairs of T-shaped slots on the two bowtie-shaped patches separately. This structure changes the path of the current and keeps the cross polarization under -40 dB. By introducing two short pins, the isolation between the two ports remains more than 38 dB in the whole bandwidth with the front-to-back ratio better than 19 dB. Moreover, the proposed antenna achieving a 10-dB return loss bandwidth of 1.70-2.73 GHz has a compact structure, thus making it easy to be extended to form an array, which can be used as a base station antenna for PCS, UMTS, and WLAN/WiMAX applications.

A Compact Ultrawideband MIMO Antenna With WLAN Band-Rejected Operation for Mobile Devices

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

Method, system and computer-readable recording medium for transferring wireless power by using antennas with high orders of spherical modes

Abstract: The present invention relates to a system for transferring wireless power or signal. The system includes a first antenna; and a second antenna which is located from the first antenna at an arbitrary distance and arranged in an arbitrary direction in comparison with the first antenna, wherein respective spherical modes of the first antenna and the second antenna are allowed to have orders which are same as or larger than a predetermined value to thereby transfer wireless power between the first antenna and the second antenna.

Closely-Packed UWB MIMO/Diversity Antenna With Different Patterns and Polarizations for USB Dongle Applications

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

Very Compact Printed Triple Band-Notched UWB Antenna With Quarter-Wavelength Slots

Abstract: A very compact coplanar waveguide (CPW)-fed ultrawideband (UWB) printed monopole antenna (PMA) with triple band-notched characteristics is presented. The antenna uses three open-ended quarter-wavelength slots to create triple band-notched characteristics in 3.3-3.7 GHz for WiMAX, 5.15-5.825 GHz for WLAN, and 7.25-7.75 GHz for downlink of X-band satellite communication systems, respectively. The open-ended quarter-wavelength slot is analyzed in detail. Surface current distributions are used to show the effect of these slots. The antenna shows broad bandwidth and good omnidirectional radiation patterns in the passband, with a very compact size of 19 × 24 mm2.

Analysis and Design of a Compact Dual-Band Directional Antenna

Abstract: A new type of compact dual-band directional antenna is proposed for 2.4/5-GHz wireless access point and RFID reader applications. The dual-band antenna consists of a longer dipole for the lower band and a pair of shorter dipoles for the upper band. A simple coupling microstrip line is employed to excite the dipoles. Both the dual-band antenna and the feeding microstrip line are printed on the same substrate, leading to a fully planar structure. The length of the dipole for the lower band is shortened by a capacitive loading at each end of the dipole, offering a compact antenna configuration. The compact dual-band antenna achieves a desirable directional radiation pattern with an antenna gain of near 8 dBi for the lower band and 9-10 dBi for the upper band. An equivalent circuit analysis for the design of the dual-band directional antenna is presented.

Bandwidth Enhancement of a Microstrip Line-Fed Printed Wide-Slot Antenna With a Parasitic Center Patch

Abstract: A printed wide-slot antenna with a parasitic patch for bandwidth enhancement is proposed and experimentally investigated. A simple 50-Ω microstrip line is used to excite the slot. A rotated square slot resonator is considered as reference geometry. The rotated square slot antenna exhibits two resonances (f1 : lower resonant frequency, f2: higher resonant frequency). By embedding a parasitic patch into the center of the rotated square slot, the lower resonant frequency is decreased and the higher resonant frequency is increased. Thus, broadband characteristic of the wide-slot antenna is achieved. The measured results demonstrate that this structure exhibits a wide impedance bandwidth, which is over 80% for |S11| ≤ -10 dB ranging from 2.23 to 5.35 GHz. Also, a stable and omnidirectional radiation pattern is observed within the operating bandwidth. In this design, a smaller ground plane is considered compared to the reference antenna (rotated square slot antenna without the parasitic center patch).

A Novel UWB Antenna With Dual Notched Bands for WiMAX and WLAN Applications

Abstract: A novel planar ultrawideband (UWB) antenna with dual notched bands is proposed and investigated. The antenna consists of a square patch and a modified grounded plane. To realize dual notched bands characteristics, a T-shaped stub embedded in the square slot of the radiation patch and a pair of U-shaped parasitic strips beside the feed line is used. The advantage of this antenna is the high rejection level in the stopband. The measured results show that the proposed dual-notched-bands planar antenna shows a very wide bandwidth from 2.8 to 11.0 GHz defined by voltage standing wave ratio VSWR <; 2, with two notched bands of 3.3-4.0 GHz (WiMAX band) and 5.05-5.90 GHz (WLAN band), respectively. Both the experimental and simulated results of the proposed antenna are presented, indicating that the antenna is a good candidate for various UWB applications.

Antenna selection based on orientation, and related apparatuses, antenna units, methods, and distributed antenna systems

Abstract: Antenna apparatuses and related antenna units that include antenna selection based on orientation are disclosed. Related methods and distributed antenna systems are also disclosed. Antenna selection is provided between two or more antennas disposed in different polarization orientations according to orientation of the antenna unit in which the antennas are included. The antenna(s) oriented most closely to perpendicular to the ground in one embodiment may be selected for use in wireless communications with wireless client devices. In this manner, the antenna(s) employed in wireless communications is likely to be the closest in polarization to the polarization of wireless client device antennas. Otherwise, an unacceptable reduction in communications link quality with the wireless client devices may occur.

High performance low profile antennas

Abstract: A leaky dielectric travelling wave surface waveguide antenna provides a multiband, low-profile antenna for satellite and other wideband (Ku/K/Ka/Q) communications applications. The antenna structure can be arranged into various types of arrays to yield a cost-effective, wideband/multiband operation with high power. In one implementation, the antenna includes a waveguide having a multi-layer substrate, a top surface, a feed (excitation) end, and a load end. One or more scattering features are disposed on the top surface of the waveguide or within the waveguide, and achieve operation in a leaky propagation mode. A wavelength correction element adds linear delay to incident energy received or transmitted by the antenna. The resulting structure permits a resulting beam direction of the antenna to be independent of the wavelength.

60-GHz LTCC Integrated Circularly Polarized Helical Antenna Array

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

Power combiner using tri-plane antennas

Abstract: A power combining apparatus includes a waveguide structure and a plurality of antenna elements arranged in the waveguide structure, wherein each of the antenna elements comprises a center planar antenna layer, two outer planar antenna layers arranged on opposite sides of the center planar antenna layer, a non-conductive layer between the center planar antenna layer and one of the outer planar antenna layers, and another non-conductive layer between the center planar antenna and the other one of the outer planar antenna layers. The power combining apparatus includes a waveguide structure having an input, an output, and a plurality of antenna elements arranged in the waveguide structure, wherein each antenna element is configured to transform an electric field direction of an electromagnetic field by substantially 90 degrees rotation about a longitudinal axis of the waveguide structure, wherein a bandwidth of the antenna is less than, equal to, or greater than a decade of frequency range.

Small UWB Planar Monopole Antenna With Added GPS/GSM/WLAN Bands

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

A Compact Polyimide-Based UWB Antenna for Flexible Electronics

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

Electromagnetic-radiation power-supply mechanism and microwave introduction mechanism

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

Universal microwave waveguide joint and mechanically steerable microwave transmitter

Abstract: A universal joint comprising a pair of circular waveguide ball-joints and a slip-joint allows for simultaneous 3-axis rotation and 3-dimensional translation between an antenna and a stationary source. As such, the universal joint does not have to be physically aligned with the azimuth, and elevation, rotation axis of the antenna and mounted on the gimbal support, greatly simplifying the antenna steering mechanism. The universal joint allows the antenna to be mass-balanced in relation to the azimuth and elevation axis without adding any additional counter weights, thus reducing the size and power requirements of the azimuth and elevation rotation drive systems. Additional ball-joints may be provided to increase the allowed range of motion of the antenna.

Low Profile Fully Planar Folded Dipole Antenna on a High Impedance Surface

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

Single Feed Stacked Patch Circular Polarized Antenna for Triple Band GPS Receivers

Abstract: A novel design of a circular polarized antenna for multiband GPS receivers is presented. The design employs the concept of multistacked patches fed through a single coaxial probe. Three patches being stacked together with a slit and symmetry I-slot are used to achieve triple operating frequency bands for GPS including L1 (1.575 GHz), L2 (1.227 GHz) and L5 (1.176 GHz). The proposed antenna has achieved a bandwidth of 2.0%, 1.5%, and 1.7% at GPS L1, L2, and L5 bands, respectively. It exhibits a minimum axial ratio of 0.51 dB with broad beamwidth in the upper hemisphere required for the GPS applications. The design of the proposed antenna is verified in the experiment. In addition, a detailed analysis has been carried out to study the effects of different geometrical parameters on the performance of the antenna.

A Compact Circularly Polarized Cross-Shaped Slotted Microstrip Antenna

Abstract: A compact cross-shaped slotted microstrip patch antenna is proposed for circularly polarized (CP) radiation. A symmetric, cross shaped slot is embedded along one of the diagonal axes of the square patch for CP radiation and antenna size reduction. The structure is asymmetric (unbalanced) along the diagonal axes. The overall size of the antenna with CP radiation can be reduced by increasing the perimeter of the symmetric cross-shaped slot within the first patch quadrant of the square patch. The performance of the CP radiation is also studied by varying the size and angle variation of the cross-shaped slot. A measured 3-dB axial-ratio (AR) bandwidth of around 6.0 MHz is achieved with the CP cross-shaped slotted microstrip antenna, with an 18.0 MHz 10-dB return-loss bandwidth. The measured boresight gain is more than 3.8 dBic over the operating band, while the overall antenna volume is 0.273λo × 0.273λo × 0.013λo (λο operating wavelength at 910 MHz).

A Low-Profile Magneto-Electric Dipole Antenna

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

Wearable textile antenna in substrate integrated waveguide technology

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

Design of a Wideband Horizontally Polarized Omnidirectional Printed Loop Antenna

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

Telemetry antennas for medical devices and medical devices including telemetry antennas

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

60 GHz Plated Through Hole Printed Magneto-Electric Dipole Antenna

Abstract: A wideband unidirectional antenna, which is composed of a planar electric dipole and a magnetic dipole formed by a vertically-oriented shorted patch antenna, is presented for millimeter wave applications. The antenna is realized by a plated through hole printed technique with the use of a microwave substrate and is excited by a T-shaped coupled strip feed. An impedance bandwidth of 33% (S11 ≤-15 dB) from 50 to 70 GHz is achieved. Stable radiation patterns with low cross polarizations and a stable antenna gain of ~7.5 dBi are achieved across the entire operating bandwidth. This single antenna element yields advantages of wideband, good directional radiation pattern and low fabrication cost.

Omnidirectional Cylindrical Dielectric Resonator Antenna With Dual Polarization

Abstract: This letter proposes an annular cylindrical dielectric resonator antenna (DRA) with two-port diversity realizing simultaneously omnidirectional horizontally and vertically polarized radiation patterns with low cross coupling. The horizontally and vertically polarized radiation patterns are achieved by exciting the orthogonal TE01δ and TM01δ modes in a single cylindrical dielectric resonator (DR). Due to the high Q-factor of the TE01δ mode, an air gap and multiple feeding lines are introduced to increase the impedance bandwidth. The proposed antenna provides an impedance bandwidth of 19.1% in the vertically polarized mode and an overlapping bandwidth of 7.4% in the horizontally polarized mode, with the overlapping band ranging from 3.78 to 4.07 GHz. Antenna diversity and multiple-input-multiple-output (MIMO) performance are examined in terms of envelope correlation coefficient and mean effective gain.

A Compact Frequency-Reconfigurable Narrowband Microstrip Slot Antenna

Abstract: A frequency-reconfigurable microstrip slot antenna is proposed. The antenna is capable of frequency switching at six different frequency bands between 2.2 and 4.75 GHz. Five RF p-i-n diode switches are positioned in the slot to achieve frequency reconfigurability. The feed line and the slot are bended to reduce 33% of the original size of the antenna. The biasing circuit is integrated into the ground plane to minimize the parasitic effects toward the performance of the antenna. Simulated and measured results are used to demonstrate the performance of the antenna. The simulated and measured return losses, together with the radiation patterns, are presented and compared.