Showing papers on "Monopole antenna published in 2013"

Compact MIMO Antenna for Portable Devices in UWB Applications

Abstract: A compact multiple-input-multiple-output (MIMO) antenna with a small size of 26×40 mm2 is proposed for portable ultrawideband (UWB) applications. The antenna consists of two planar-monopole (PM) antenna elements with microstrip-fed printed on one side of the substrate and placed perpendicularly to each other to achieve good isolation. To enhance isolation and increase impedance bandwidth, two long protruding ground stubs are added to the ground plane on the other side and a short ground strip is used to connect the ground planes of the two PMs together to form a common ground. Simulation and measurement are used to study the antenna performance in terms of reflection coefficients at the two input ports, coupling between the two input ports, radiation pattern, realized peak gain, efficiency and envelope correlation coefficient for pattern diversity. Results show that the MIMO antenna has an impedance bandwidth of larger than 3.1-10.6 GHz, low mutual coupling of less than -15 dB, and a low envelope correlation coefficient of less than 0.2 across the frequency band, making it a good candidate for portable UWB applications.

Flexible and Compact AMC Based Antenna for Telemedicine Applications

Abstract: We present a flexible, compact antenna system intended for telemedicine applications. The design is based on an M-shaped printed monopole antenna operating in the Industrial, Scientific, and Medical (ISM) 2.45 GHz band integrated with a miniaturized slotted Jerusalem Cross (JC) Artificial Magnetic Conductor (AMC) ground plane. The AMC ground plane is utilized to isolate the user's body from undesired electromagnetic radiation in addition to minimizing the antenna's impedance mismatch caused by the proximity to human tissues. Specific Absorption Rate (SAR) is analyzed using a numerical human body model (HUGO) to assess the feasibility of the proposed design. The antenna expresses 18% impedance bandwidth; moreover, the inclusion of the AMC ground plane increases the front to back ratio by 8 dB, provides 3.7 dB increase in gain, in addition to 64% reduction in SAR. Experimental and numerical results show that the radiation characteristics, impedance matching, and SAR values of the proposed design are significantly improved compared to conventional monopole and dipole antennas. Furthermore, it offers a compact and flexible solution which makes it a good candidate for the wearable telemedicine application.

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).

A Compact Dual-Band Rectenna Using Slot-Loaded Dual Band Folded Dipole Antenna

Abstract: A compact dual-band rectenna operating at 915 MHz and 2.45 GHz is presented. The rectenna consists of a slot-loaded dual-band folded dipole antenna and a dual-band rectifier. The length of the proposed antenna is only 36.6% of the half-wavelength $(\lambda_{0}/2)$ dipole antenna at 915 MHz while keeping dual-band property at 915 MHz and 2.45 GHz. The rectifier circuit is optimized for low input power densities using harmonic balance (HB) simulation. The efficiencies of the rectifier are evaluated with both single- and dual-frequency input signals. The measured results show an efficiency of 37% and 30% at 915 MHz and at 2.45 GHz when illuminated by a microwave signal of available power of $-$ 9 dBm for a load resistor of 2.2 k $\Omega$ .

Dual antenna integrated carrier aggregation front end solution

Abstract: Radio frequency front end circuitry comprises a first antenna port, a second antenna port, antenna switching circuitry, a first diplexer, and a second diplexer. The antenna switching circuitry is coupled to each of the first antenna port and the second antenna port through the first diplexer and the second diplexer, respectively. The antenna switching circuitry is adapted to selectively couple one or more of a plurality of transmit and receive ports to the first antenna port and the second antenna port.

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.

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.

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.

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.

Wideband Planar Array With Integrated Feed and Matching Network for Wide-Angle Scanning

Abstract: It is traditionally known that wideband apertures lose bandwidth when placed over a ground plane. To overcome this issue, this paper introduces a new non-symmetric tightly coupled dipole element for wideband phased arrays. The proposed array antenna incorporates additional degrees of freedom to control capacitance and cancel the ground plane inductance. Specifically, each arm on the dipole is different than the other (or non-symmetric). The arms are identical near the center feed section but dissimilar towards the ends, forming a ball-and-cup. It is demonstrated that the non-symmetric qualities achieve wideband performance. Concurrently, a design example for planar installation with balun and matching network is presented to cover X-band. The balun avoids extraneous radiation, maintains the array's low-profile height and is printed on top of the ground plane connecting to the array aperture with 180° out of phase vertical twin-wire transmission lines. To demonstrate the concept, a 64-element array with integrated feed and matching network is designed, fabricated and verified experimentally. The array aperture is placed λ/7 (at 8 GHz) above the ground plane and shown to maintain a active VSWR less than 2 from 8-12.5 GHz while scanning up to 70° and 60° in E- and H-plane, respectively. The array's simulated diagonal plane cross-polarization is approximately 10 dB below the co-polarized component during 60° diagonal scan and follows the theoretical limit for an infinite current sheet.

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.

A Compact, Planar, and CPW-Fed Metamaterial-Inspired Dual-Band Antenna

Abstract: A novel compact, planar, and coplanar waveguide (CPW)-fed dual-band antenna is designed and proposed using composite metamaterial. Such composite metamaterial consists of an inner split-ring resonator (SRR) and an outer closed-ring resonator (CRR). The composite metamaterial can provide dual-band operation at 2.595-2.654 and 3.185-4.245 GHz with reflection coefficient better than -10 dB by the two resonant modes of SRR and CRR, respectively. A CPW-fed line with trapeziform ground plane and tapered impedance transformer line is employed to improve the impedance matching of the antenna. The uniqueness of this design is that the inner SRR with size much smaller than the resonant wavelength is used for obtaining the lower narrow frequency band, which makes the dual-band antenna very compact. Antenna parameters, including reflection coefficient, radiation pattern, radiation efficiency, and gain, are analyzed with numerical simulation and experimental measurement. Good agreement between the simulation and measurement is observed.

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 Reconfigurable Triple-Notch-Band Antenna Integrated with Defected Microstrip Structure Band-Stop Filter for Ultra-Wideband Cognitive Radio Applications

Abstract: A printed reconfigurable ultra-wideband (UWB) monopole antenna with triple narrow band-notched characteristics is proposed for cognitive radio applications in this paper. The triple narrow band-notched frequencies are obtained using a defected microstrip structure (DMS) band stop filter (BSF) embedded in the microstrip feed line and an inverted π-shaped slot etched in the rectangular radiation patch, respectively. Reconfigurable characteristics of the proposed cognitive radio antenna (CRA) are achieved by means of four ideal switches integrated on the DMS-BSF and the inverted π-shaped slot. The proposed UWB CRA can work at eight modes by controlling switches ON and OFF. Moreover, impedance bandwidth, design procedures, and radiation patterns are presented for analysis and explanation of this antenna. The designed antenna operates over the frequency band between 3.1 GHz and 14 GHz (bandwidth of 127.5%), with three notched bands from 4.2 GHz to 6.2 GHz (38.5%), 6.6 GHz to 7.0 GHz (6%), and 12.2 GHz to 14 GHz (13.7%). The antenna is successfully simulated, fabricated, and measured. The results show that it has wide impedance bandwidth, multimodes characteristics, stable gain, and omnidirectional radiation patterns.

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.

Monopole-Like and Boresight Pattern Reconfigurable Antenna

Abstract: A novel pattern reconfigurable antenna is proposed to achieve two different radiation patterns by controlling the bias voltage of switches. Initially, the proposed antenna operates as a top-loaded monopole antenna fed by a co-planar waveguide (CPW). When the slot from the CPW is disturbed by switching on PIN diodes, it operates as a slot antenna. Therefore, when the switch turns on, the maximum radiation intensity occurs at the normal to the aperture surface defined as the boresight direction, which is similar to a slot antenna. When the switch turns off, the maximum radiation intensity occurs at right angles to the boresight direction, which is similar to a monopole antenna. The pattern reconfigurable capability is successfully demonstrated at 2.3 GHz by full-wave simulation and measurement.

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.

Substrate Integrated Metamaterial-Based Leaky-Wave Antenna With Improved Boresight Radiation Bandwidth

Abstract: A substrate integrated metamaterial-based leaky-wave antenna is proposed to improve its boresight radiation bandwidth. The proposed leaky-wave antenna based on a composite right/left-handed substrate integrated waveguide consists of two leaky-wave radiator elements which are with different unit cells. The dual-element antenna prototype features boresight gain of 12.0 dBi with variation of 1.0 dB over the frequency range of 8.775-9.15 GHz or 4.2%. In addition, the antenna is able to offer a beam scanning from to with frequency from 8.25 GHz to 13.0 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.