Showing papers on "Coaxial antenna published in 2013"

Design and Analysis of a Low-Profile and Broadband Microstrip Monopolar Patch Antenna

Abstract: A new microstrip monopolar patch antenna is proposed and analyzed. The antenna has a wide bandwidth and a monopole like radiation pattern. Such antenna is constructed on a circular patch antenna that is shorted concentrically with a set of conductive vias. The antenna is analyzed using a cavity model. The cavity model analysis not only distinguishes each resonating mode and gives a physical insight into each mode of the antenna, but also provides a guideline to design a broadband monopolar patch antenna that utilizes two modes (TM01 and TM02 modes). Both modes provide a monopole like radiation pattern. The proposed antenna has a simple structure with a low profile of 0.024 wavelengths, and yields a wide impedance bandwidth of 18% and a maximum gain of 6 dBi.

Circular Polarization Reconfigurable Wideband E-Shaped Patch Antenna for Wireless Applications

Abstract: A polarization reconfigurable E-shaped patch antenna with wideband performance is proposed in this communication. The antenna is capable of switching its polarization from right hand circular polarization (RHCP) to left hand circular polarization (LHCP) and vice versa. Its structure is simple and consists of a single-layer single-feed E-shaped patch and two RF switches placed at appropriate locations in the slots. The design targets the WLAN IEEE 802.11 b/g frequency band (2.4-2.5 GHz) being used in various wireless communication systems. Full wave simulation is used for the antenna analysis, and a prototype of the antenna with an integrated DC biasing circuit has been fabricated and tested. Good agreement is obtained between simulated and measured results. The antenna exhibits a 7% effective bandwidth from 2.4 GHz to 2.57 GHz with a 8.7 dBic maximum gain. The antenna radiation symmetry is maintained upon switching between the two circular polarization modes.

Compact Dual Band-Notched UWB MIMO Antenna With High Isolation

Abstract: A compact dual band-notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with high isolation is designed on a FR4 substrate (27 × 30 × 0.8 mm3). To improve the input impedance matching and increase the isolation for the frequencies ≥ 4.0 GHz, the two antenna elements with compact size of 5.5 × 11 mm2 are connected to the two protruded ground parts, respectively. A 1/3 λ rectangular metal strip producing a 1.0 λ loop path with the corresponding antenna element is used to obtain the notched frequency from 5.15 to 5.85 GHz. For the rejected band of 3.30-3.70 GHz, a 1/4 λ open slot is etched into the radiator. Moreover, the two protruded ground parts are connected by a compact metal strip to reduce the mutual coupling for the band of 3.0-4.0 GHz. The simulated and measured results show a bandwidth with |S11| ≤ -10 dB, |S21| ≤ -20 dB and frequency ranged from 3.0 to 11.0 GHz excluding the two rejected bands, is achieved, and all the measured and calculated results show the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems.

A Differentially-Driven Dual-Polarized Magneto-Electric Dipole Antenna

Abstract: A novel differentially-driven dual-polarized antenna is proposed in this communication. It is a magneto-electric dipole antenna whose gain and beamwidth keep constant along frequency within the operation bandwidth. If the antenna is ideally symmetrical, its differential port-to-port isolation is theoretically infinite. Due to the differentially-driven scheme, its cross-polarization level can be very low. Measurement shows that the proposed antenna achieves a wide impedance bandwidth of 68% (0.95 to 1.92 GHz) for differential reflection coefficients less than -10 dB and high differential port-to-port isolation of better than 36 dB within the bandwidth. The 3-dB-gain bandwidth of the proposed antenna is 62% (1.09 to 2.08 GHz), and the radiation pattern across it is stable and unidirectional. The broadside gain within the 3-dB-gain bandwidth ranges from 6.6 to 9.6 dBi. The cross-polarization level is lower than -23 dB across the 3-dB-gain bandwidth. The proposed antenna is the first differentially-driven dual-polarized magneto-electric dipole antenna. A feeding structure is specially designed to fit the differentially-driven scheme, and also to achieve wide impedance and gain bandwidths.

A CPW-Fed Compact UWB Microstrip Antenna

Abstract: A novel coplanar waveguide (CPW)-fed compact ultrawideband (UWB) microstrip antenna is proposed for ultrawideband applications. The proposed antenna posseses a method to minimize the monopole antenna by loading of inverted L-strip over the conventional monopole patch antenna to lower the height of the antenna. The ground was vertically extended toward two sides of the single radiator. Therefore, the large space around the radiator that is usually wasted can be effectively saved. The antenna is practically fabricated and simulated. Measured results show a good agreement with simulated results. The prototype with overall size of $25 \times 25 \times 1.6\ {\hbox{mm}}^3$ achieves good impedance matching, constant gain, stable radiation patterns, and constant group delay over an operating bandwidth of 2.6-13.04 GHz (10.44 GHz).

Wireless power orthogonal polarization antenna array

Abstract: Systems and methods for wireless power transmission are described herein In one aspect, an apparatus for wireless power transmission comprises a first antenna array of antenna coils configured to generate a first wireless field A second antenna array of antenna coils generates a second wireless field The first antenna array at least partially overlaps the second antenna array A driver circuit generates first and second drive signals for generation of the first and second wireless fields via the first and second antenna arrays, respectively The first wireless field is orthogonal with respect to the second wireless field The first antenna array and the driver circuit power the antenna coils of the first antenna array with alternating polarities The second antenna array and the driver circuit power the antenna coils of the second antenna array with alternating polarities

Antenna system facilitating reduction of interfering signals

Abstract: Described embodiments include an antenna system and method. The antenna system includes a surface scattering antenna that has an electromagnetic waveguide structure and a plurality of electromagnetic wave scattering elements. The plurality of electromagnetic wave scattering elements are distributed along the waveguide structure, have a respective activatable electromagnetic response to a guided propagating electromagnetic wave, and produce a controllable radiation pattern. A gain definition circuit defines a radiation pattern configured to acquire a possible interfering signal. The defined antenna radiation pattern has a field of view covering at least a portion of an undesired field of view of an associated antenna. An antenna controller establishes the defined radiation pattern in the surface scattering antenna by activating the respective electromagnetic response of selected electromagnetic wave scattering elements. A correction circuit reduces an influence of the received possible interfering signal in a contemporaneously received signal by the associated antenna.

Phased array antenna

Abstract: An antenna element having a vertically stacked structure and a phased array antenna that includes a plurality of antenna elements sharing a common conductive ground plane are described. The phased array antenna also includes a common conductive shell electrically coupled to the common conductive ground plane and extending away there from to encompass the antenna elements. The common conductive shell and the common conductive ground plane together define a common cavity having a common aperture. The phased array antenna also includes a common dielectric superstrate layer disposed over the common cavity at a predetermined distance from the antenna elements and a beam steering system coupled to the antenna elements and configured for steering an energy beam produced by the phased array antenna.

Lens antenna with electronic beam steering capabilities

Abstract: The invention discloses a lens antenna with high directivity intended for use in radio-relay systems, said antenna providing the capability of electronic steering of the main radiation pattern beam by switching between horn antenna elements placed on a plane focal surface of the lens. Electronic beam steering allows antenna to automatically adjust the beam direction during initial alignment of transmitting and receiving antennas and in case of small antenna orientation changes observed due to the influence of different reasons (wind, vibrations, compression and/or extension of portions of the supporting structures with the temperature changes, etc.). The technical result of the invention is the increase of antenna directivity with simultaneously provided capability of scanning the beam in continuous angle range and also the increase of antenna radiation efficiency and, consequently, the increase of the lens antenna gain. This result is achieved by the implementation of horn antenna elements with optimized geometry.

Frequency-Reconfigurable Microstrip Patch-Slot Antenna

Abstract: A frequency-reconfigurable microstrip patch switchable to slot antenna is proposed. The antenna is capable of frequency switching at nine different frequency bands between 1.98 and 3.59 GHz. The patch is resonating at 3.59 GHz, while the slot produces eight different operating frequencies between 1.98 and 3.41 GHz. Five RF p-i-n diode switches are positioned in the slot to achieve frequency reconfigurability. 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.

Antenna array with asymmetric elements

Abstract: An RFID reader is provided that includes an antenna array comprising multiple antenna elements circumferentially distributed around a longitudinal axis of the antenna array. Each antenna element includes multiple patch elements disposed above one or more underlying substrates, wherein the patch elements of each antenna element are disposed on an outer side of the antenna element. Further, one or more of the antenna elements is an asymmetric antenna element, wherein a first end of the asymmetric antenna element is wider than a second, opposite end of the asymmetric antenna element, wherein a first patch element disposed proximate to the first end of the asymmetric antenna element is larger than a second patch element disposed proximate to the second end of the asymmetric antenna element, and wherein a resonant frequency associated with the first patch element is approximately the same as a resonant frequency associated with the second patch element.

Adjustable slot antenna for control of uniformity in a surface wave plasma source

Abstract: The present invention provides a surface wave plasma source including an electromagnetic (EM) wave launcher comprising a slot antenna having a plurality of antenna slots configured to couple the EM energy from a first region above the slot antenna to a second region below the slot antenna, and a power coupling system is coupled to the EM wave launcher. A dielectric window is positioned in the second region and has a lower surface including the plasma surface. A slotted gate plate is arranged parallel with the slot antenna and is configured to be movable relative to the slot antenna between variable opacity positions including a first opaque position to prevent the EM energy from passing through the first arrangements of antenna slots, and a first transparent position to allow a full intensity of the EM energy to pass through the first arrangement of antenna slots.

A Novel Broadband Planar Antenna for 2G/3G/LTE Base Stations

Abstract: A novel broadband planar antenna is developed for mobile communication base stations. The antenna is composed of a pair of folded dipoles which are coupling fed by an L-shaped microstrip line. Both the dipoles and the coupling microstrip line are etched on the same substrate. The planar antenna achieves a bandwidth of 53% for ${\rm return\ loss} > 15$ dB, covering the frequency range 1.65–2.85 GHz for 2G/3G/LTE applications. The antenna gain of the broadband antenna element is about 9 dBi. A ${\pm}45^{\circ}$ dual-polarized planar antenna consisting of two broadband antenna elements is proposed, which achieves a bandwidth of about 50% and an isolation of 30 dB. Two 8-element antenna arrays are developed respectively for the broadband antenna and for the ${\pm}45^{\circ}$ dual-polarized antenna. Both antenna arrays achieve a bandwidth of more than 58% (1.6–2.9 GHz). The antenna gains achieved for the both antenna arrays are higher than 15.5 dBi. The half-power beam widths in the horizontal plane for the antenna arrays are approximately $65\pm 10^{\circ}$ , suitable for base station applications.

A Broadband Dual-Polarized Omnidirectional Antenna for Base Stations

Abstract: A broadband vertically/horizontally dual-polarized omnidirectional antenna is proposed for mobile communications. The dual-polarized antenna is a combination of a modified low-profile monopole for vertical polarization (VP) and a circular planar loop for horizontal polarization (HP). The modified low-profile monopole is a circular folded patch shorted by four tubes while the circular loop consists of four half-wavelength arc dipoles. The dual-polarized omnidirectional antenna achieves a bandwidth of ~ 25% (1.7-2.2 GHz) with an isolation of around 40 dB. The gain variations in the horizontal plane are less than 2.5 dB for VP and 1.5 dB for HP. An eight-element dual-polarized antenna array is developed for base station applications. The antenna gains of the array for both VP and HP are ~ 8 dBi with a difference of less than 1 dB. The beamwidths in the vertical plane are 9±1° for VP and 9±1.5° for HP. The cross-polarization levels in the horizontal plane for both VP and HP are lower than -20 dB.

A CSRR Loaded MIMO Antenna System for ISM Band Operation

Abstract: A 2 × 2 (four-element) multiple-input multiple-output (MIMO) patch antenna system is designed and fabricated for a 2.45-GHz ISM band operation. It uses complementary split-ring resonator (CSRR) loading on its ground plane for antenna miniaturization. This reduces the single-element antenna size by 76%. The total board size of the proposed MIMO antenna system, including the GND plane is 100 × 50 × 0.8 mm3, while the single-patch antenna element has a size of 14 × 18 mm2. The antenna is fabricated and tested. Measured results are in good agreement with simulations. A minimum measured isolation of 10 dB is obtained given the close interelement spacing of 0.17λ. The maximum measured gain for a single operating element is -0.8 dBi.

Wide Band Dual-Beam U-Slot Microstrip Antenna

Abstract: A wide band dual-beam microstrip antenna is proposed in this communication. Two radiation beams off broadside are obtained by operating the patch antenna at the higher order TM02 mode instead of the fundamental mode, which radiates a broadside beam. Broadening the antenna bandwidth is achieved by using the U-slot technique. Unlike previous work on the conventional U-slot microstrip antenna, the effect of the U-slot inclusion on the performance of a patch antenna operating at the TM02 mode is studied across the entire achieved bandwidth. The antenna analysis is carried out with the aid of full wave simulation, and an antenna prototype is fabricated and measured for validation. Good agreement between the simulated and measured results is observed. The antenna operating frequency range is 5.18-5.8 GHz with VSWR less than 2, which corresponds to 11.8% impedance bandwidth. It exhibits two radiation beams, directed at 35° and -33° with 7.92 dBi and 5.94 dBi realized gain, respectively at 5.5 GHz.

Research on a Novel Miniaturized Antipodal Vivaldi Antenna With Improved Radiation

Abstract: A novel antipodal Vivaldi antenna (AVA) is proposed in this letter. The addition of regular slot edges (RSE) helps the antenna lower the low-end operating frequency by 9% with the dimension unaltered, while the radiation patterns at higher frequencies are improved due to the loaded lens and the choke slot edges (CSE) configuration at the termination of the flares, which also contribute to the enhancement of antenna gain. The improved antenna is fabricated and verified experimentally. The measured results coincide with the simulated ones perfectly, which proves the feasibility of the novel design.

60-GHz Circularly Polarized U-Slot Patch Antenna Array on LTCC

Abstract: This communication presents a 60-GHz wideband circularly polarized (CP) U-slot patch antenna array of 4 × 4 elements on low temperature cofired ceramic (LTCC). A CP U-slot patch antenna is used as the array element to enhance the impedance bandwidth and a stripline sequential rotation feeding scheme is applied to achieve wide axial ratio (AR) bandwidth. Meanwhile, a grounded coplanar waveguide (GCPW) to stripline transition is designed for probe station measurement. The fabricated antenna array has a dimension of 14 ×16 × 1.1 mm3 . The simulated and measured impedance bandwidths, AR bandwidths, and radiation patterns are investigated and compared. Measured results show that the proposed antenna array has a wide impedance bandwidth from 50.5 GHz to 67 GHz for |S11| <; -10 dB, and a wide AR bandwidth from 54 GHz to 65.5 GHz for AR <; 3 dB. In addition, it exhibits a peak gain of 16 dBi and a beam-shaped pattern with 3-dB beam width of 20°. Moreover, its AR keeps below 3 dB within the 3-dB beam width.

Multiband monopole antenna with complementary split-ring resonators for WLAN and WiMAX applications

Abstract: Presented is an electrically small multiband monopole antenna based on complementary split-ring resonators, which are used to reduce antenna size. The antenna is fed by a three-stage microstrip line and provides 13, 17 and 16% impedance bandwidth performance covering the 3.5 GHz WiMAX and 2.4/5.2 GHz WLAN bands. Also, the proposed antenna exhibits almost an omnidirectional radiation pattern in the H-plane and a dipole-like radiation pattern in the E-plane. The return loss and radiation pattern measurements of the fabricated antenna are in very good agreement with simulation results.

Wearable Textile Half-Mode Substrate-Integrated Cavity Antenna Using Embroidered Vias

Abstract: A wearable textile antenna based on the fundamental mode of a half-mode substrate-integrated semicircular cavity is presented. The antenna operates around 5 GHz and is manufactured with two layers of silver fabric conductors, on the top and bottom of a low-permittivity low-loss foam with minimal water absorption. The vias are realized with five passes of conductive yarn with a diameter of 0.12 mm placed every 1 mm. Their precise arrangement is obtained using computerized embroidery. Compared to other antenna concepts, this design features minimal manufacturing complexity as it does not require accurate patterned cutting of textile conductors. Good isolation from the human body and robustness in terms of deformation are further key characteristics of this structure. This letter provides design guidelines and investigates realistic issues associated with the manufacturing technique. A good agreement between simulated and measured performance with a gain of 7.2 dB validates the concept.

A Compact Printed Antenna for Triple-Band WLAN/WiMAX Applications

Abstract: In this letter, a novel compact printed antenna for triple-band WLAN/WiMAX applications is presented. The proposed antenna consists of three simple circular-arc-shaped strips, whose whole geometry looks like “ear” type. By adjusting the geometries and the sizes of these three circular-arc-shaped strips, three different resonance modes can be effectively created for three distinct frequency bands, respectively. The overall dimension of the proposed antenna can reach $18\times 37\times 1\ {\hbox{mm}}^{3}$ . Measured results show that the presented antenna can cover three separated impedance bandwidths of 400 MHz (2.38–2.78 GHz), 480 MHz (3.28–3.76 GHz), and 1000 MHz (4.96–5.96 GHz), which are well applied for both 2.4/5.2/5.8-GHz WLAN bands and 2.5/3.5/5.5-GHz WiMAX bands.

Antenna assembly and system

Abstract: An antenna system includes a plurality of antenna assemblies. The antenna assemblies include a driven component and a director array to increase the gain of the antenna assembly. For each antenna assembly of the plurality of antenna assemblies, the driven component and director array are disposed in an antenna plane. Each antenna assembly is arranged in a different geometrical plane.

A Compact Filtering Antenna With Flat Gain Response Within the Passband

Abstract: A compact filtering antenna is designed for the modern wireless communication systems in this letter. First, a two-pole Butterworth bandpass filter is designed. Then, by substituting the second port and resonator with fan-shaped patch antenna (traditional antenna) with defected ground structure (DGS), a filtering antenna is formed. Compared to the traditional antenna, the filtering antenna obtains the flatter gain response within the passband, good selectivity at the passband edge, and the wider bandwidth. Measured results show that the filtering antenna can operate at 2.4 GHz and has a 460-MHz bandwidth and a 2.3-dBi peak gain within the passband. Moreover, a radiation zero occurs at 3 GHz.

A Novel Miniaturized Broadband Dual-Polarized Dipole Antenna for Base Station

Abstract: A novel dual-polarized dipole antenna for base-station applications is presented in this letter. The proposed antenna is composed of a cross dipole, a square loop, a square plate, and a small-size reflector. The square loop and the square plate act as a parasitic radiator and a director, respectively. By introducing the two parts, the impedance bandwidth of the cross dipole can be significantly enhanced, and broadside radiation patterns with narrow beam can be also obtained. Experimental results show that the proposed antenna can operate from 1.71 to 2.69 GHz with low VSWRs at the two ports. High isolation ( > 22 dB) and stable antenna gain (~ 8 dB) are also achieved over the entire operating frequency band. The antenna has symmetrical radiation patterns both in vertical and horizontal planes, and the half-power beamwidth is 70°±5°. Furthermore, the size of the proposed antenna is very compact, which is only 0.513 λ0 ×0.513 λ0 ×0.388 λ0 at the center of the operating frequency band.

Omnidirectional Circularly Polarized Dielectric Resonator Antenna With Top-Loaded Alford Loop for Pattern Diversity Design

Abstract: A new compact omnidirectional circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) with a top-loaded modified Alford loop is investigated. Fed by an axial probe, the DRA is excited in its TM01δ-mode, which radiates like a vertically polarized electric monopole. The modified Alford loop comprises a central circular patch and four curved branches. It is placed on the top of the DRA and provides an equivalent horizontally polarized magnetic dipole mode. Omnidirectional CP fields can be obtained when the two orthogonally polarized fields are equal in amplitude but different in phase by 90°. This CP DRA is applied to the design of a two-port CP diversity DRA which provides omnidirectional and broadside radiation patterns. The broadside radiation pattern is obtained by making use of the broadside HEM12δ+ 1-mode of the DRA, which is excited by a balanced slot serially fed by a microstrip line. For demonstration, both the omnidirectional CP DRA and the diversity CP DRA were designed at ~ 2.4 GHz for WLAN applications. Their S-parameters, axial ratios, radiation patterns, antenna gains, and antenna efficiencies are studied. The envelope correlation is also found for the diversity design. Reasonable agreement between the simulated and measured results is observed.

A Differential-Fed Magneto-Electric Dipole Antenna for UWB Applications

Abstract: A new magneto-electric dipole antenna with a unidirectional radiation pattern is proposed. A novel differential feeding structure is designed to provide an ultra-wideband impedance matching. A stable gain of 8.25±1.05 dBi is realized by introducing two slots in the magneto-electric dipole and using a rectangular box-shaped reflector, instead of a planar reflector. The antenna can achieve an impedance bandwidth of 114% for SWR ≤ 2 from 2.95 to 10.73 GHz. Radiation patterns with low cross polarization, low back radiation, fixing broadside direction mainbeam and symmetrical E- and H -plane patterns are obtained over the operating frequency range. Moreover, the correlation factor between the transmitting antenna input signal and the receiving antenna output signal is calculated for evaluating the time-domain characteristic. The proposed antenna, which is small in size, can be constructed easily by using PCB fabrication technique.

Antenna unit, antenna assembly, multi-antenna assembly, and wireless connection device

Abstract: The present invention relates to an antenna unit, including a dielectric substrate and an antenna conductor attached to the dielectric substrate, where a maximum gain direction of the antenna unit is consistent with an extension direction of a surface of the dielectric substrate. The present invention also relates to an antenna assembly with the antenna unit, a multi-antenna assembly, and a wireless connection device with the antenna unit, the antenna assembly or the multi-antenna assembly. The antenna unit of the present invention has high directivity, and has advantages of broad bands, high gains, and easy commissioning, so that both the multi-antenna assembly and the wireless connection device have high performance.

Wideband Circularly Polarized AMC Reflector Backed Aperture Antenna

Abstract: A wideband, circularly polarized (CP), artificial magnetic conductor (AMC) reflector backed octagonal-shaped aperture (OSA) antenna is proposed for unidirectional radiation. The proposed antenna consists of an OSA fed by microstrip along with L-shaped stub and an AMC reflector. Bidirectional radiation of OSA antenna is changed to unidirectional radiation using an AMC reflector. The antenna height measured from the upper surface of the AMC reflector to OSA radiator is chosen to be small to realize a low-profile antenna: at the lowest analysis frequency of 4.5 GHz. Three different surfaces are studied and compared as back reflectors for OSA: perfect electric conductor (PEC), single layered AMC surface, and double layered AMC surface. The OSA with double-layered AMC surface demonstrates the largest measured 3-dB axial ratio bandwidth of 33.2% (5.20-7.19 GHz) with impedance bandwidth of 36.2% (5.04-7.21 GHz) for VSWR of 2. Almost constant gain of around 7 dBic is achieved over the band for the overall antenna volume of 0.72λo × 0.60λo × 0.19λo at the center frequency of 6.0 GHz.

Frequency Selective Surfaces for Beam-Switching Applications

Abstract: A novel design of a beam-switching antenna based on reconfigurable frequency selective surfaces (FSSs) is presented. The antenna is composed of a cylindrical FSS with PIN diodes and divided into six equal sectors by metallic sheets. Metallic cones at the top and bottom of the structure are used to create a directive beam. The antenna is fed by a simple dipole at its center. To switch the radiation pattern of the antenna, the diodes in one FSS-sector are set off to be transparent to the incident EM waves, whereas the diodes in other sectors are on to reflect the incident wave. The direction of the radiation pattern is defined by the off-state sector. In this design, the beam-switching is achieved with only one layer and minimum size of the cylindrical active FSS in order to decrease the number of active elements, and the amount of the power supply. The antenna can sweep the entire azimuth plane with 60° radiation beamwidth in six steps. The fabricated antenna prototype operates from 2.3 GHz to 3 GHz with maximum measured gain of 10 dBi and 3-dB beamwidth of 60°. This antenna can be used in the base station of the wireless communication systems.