Bidirectional Radiation Pattern Research Articles

Rancang Bangun Antena Bowtie pada Video Sender sebagai Pemancar TV Streaming

A streaming television usually broadcasted through internet and can be watched on computer or mobile phone. However it can also be seen through television using video sender as the transmitter. To transmit it, of course, a suitable antenna is needed, in this case a bowtie antenna is selected. This research describe the design of a bowtie antenna that will be used as a transmitter antenna on a video sender. This bowtie antenna is designed by using an aluminum plate works on frequency of 655 MHz and has a return loss value of -21.127 dB, VSWR 1.192, 5.11 dB gain and bi-directional radiation pattern. The analysis process is carried out by analyzing the data taken from the audio and video results received in television as well as data from the measurement of signal strength captured by Register Transfer Level Software Define Radio (RTL SDR) and dipole antennas. Measurement results will be displayed in the sdrSharp software. The results of this measurement will be associated with field strength which is related to television signals. This bowtie antenna can transmit audio and video up to 30 m and has an average field strength value in Line of Sight (LOS) conditions of 120.3208 dBμV / m and at Non Line of Sight (NLOS) conditions of 123.5014 dBμV / m which is in accordance with the field strength standard in Indonesia that regulated in Perkominfo No. 31 Tahun 2014 which is above 70 dBμV / m in band V.

Wideband bow‐tie antenna with increased gain and directivity by using high impedance surface

Metamaterial surfaces offer a wide range of advantages in terms of antenna design. One such metamaterial is designed to capture the benefits of both high-impedance surfaces as well as artificial magnetic surfaces. The confluence of both these properties delivers an added advantage to planar antennas by delivering high gain and directivity simultaneously. Bidirectional radiation pattern has been transformed to a directional radiation pattern by placing the metamaterial as substrate beneath the antipodal bowtie antenna. In addition, zero separation between the antenna and metasurface ensures low profile. The proposed design has been verified both by simulation and measurement which have shown an improvement on gain of 3.2 dBi with an almost steady gain response inside the resonating band of the antenna which lies between 12 and 16 GHz.

Internet of Things Controlled Reconfigurable Antenna for RF Harvesting

<p>Internet of Things (IoT) controlled a reconfigurable antenna with PIN diode switch for modern wireless communication is designed and implemented. Direct contact of biasing network with the antenna is eliminated and the switching unit is manipulated through IoT method. The proposed antenna has ring structures, in which the outer ring connects the inner ring structure through a PIN diode switch. The dimension of the proposed antenna is reported as 50 mm × 50 mm and its prototype has been made-up on epoxy-Fr4 substrate with 1.6 mm thickness. This antenna setup is made to reconfigurable in four bands (4.5 GHz, 3.5 GHz, 2.4 GHz, and 1.8 GHz) through switching provided by IoT device (NodeMCU). The antenna has a good return loss greater than -10dB.In switching state 2 the antenna has a return loss of -30 dB peak is attained at 3.4 GHz of operating frequency. Similarly the gain response of antenna is good in its operating bands of all switching states and obtained a maximum gain of 2.7 dB in 3.5 GHz. Bidirectional radiation pattern is obtained in all switching states of the antenna.</p>

Tri‐band planar monopole antenna with two circularly polarised bandwidths for WiMAX applications

A tri-band planar monopole antenna with one linearly polarised band, two circularly polarised bands, and bidirectional radiation patterns is presented in this study. The antenna consists of a monopole with seven arms etched on the top side of a FR4 substrate, and a slitted ground plane on the bottom side. Measured results show that the antenna has a S 11 <;-10 dB impedance bandwidth of 9.7% (2.05-2.26 GHz) for the lower band, 11.3% (3.41-3.82 GHz) for the middle band, and 60.2% (4.89-9.11 GHz) for the upper band. The circular polarisation (CP) is radiated within the middle (left hand CP) and the upper (right hand CP) bands, and the measured broadside 3 dB axial ratio bandwidths are 4.9% (3.53-3.71 GHz) and 58.6% GHz (4.69-8.58 GHz), respectively. The proposed antenna has a total size of 25 × 35 × 1.6 mm 3 and can be employed for the 2.1 GHz UMTS, whereas the CP bands can be used for the 3.5/5.5 GHz WiMAX, 5.5 GHz Wi-Fi, and 5.2/5.8 GHz WLAN applications.

Dual-Frequency Circularly Polarized Truncated Square Aperture Patch Antenna with Slant Strip and L-Shaped Slot for WLAN Applications

This research proposes a dual-frequency circularly polarized truncated square aperture patch antenna with slant stripline and L-shaped slot for WLAN applications. In the antenna design, the parameters were optimized and the WLAN-enabled dual-frequency (2.4 and 5.8 GHz) antenna was realized. Simulations were subsequently carried out for the impedance bandwidth (S11) &lt; −10 dB, axial ratio (AR) ≤ 3 dB, optimal gain, and bidirectional radiation pattern. To validate, an antenna prototype was fabricated and the experiments were undertaken. The simulated and experimental results are in good agreement. In essence, the proposed WLAN-enabled dual-frequency circularly polarized antenna is most suited for applications in the vertically and horizontally elongated areas, including in the tunnel, train carriage, and buildings.

Bi-directional UWB MIMO Antenna for Superior Spatial Diversity, and/or Multiplexing MIMO Performance

In this paper, a two-element UWB MIMO antenna with bi-directional radiation pattern is designed for superior UWB MIMO performance. The designed antenna adopts asymmetric coplanar waveguide ground feeding. The proposed antenna ECC is lower than the ECC of its omni-directional peer antenna. Simulated and measured ECC is lower than 0.016 over the entire ultra-wide bandwidth (3.1–10.6 GHz). The isolation between elements of the designed antenna is 20–25 dB exceeding the average in recently published works. The designed antenna has a diversity gain of almost 10 dB and average multiplexing efficiency of 85% over the entire ultra-wide bandwidth. The antenna preserves radiation efficiency higher than 0.96 and gain 3 dB. The diversity performance of the proposed UWB MIMO antenna is proven through real rich-multipath indoor environment measurements. Stationarity of the elected channel is evaluated through 100 successive measurements separated by a 3-min period for 5 h long. The measured spatial correlation coefficients are much lower than 0.5 in different scenarios.

Wideband beam-steerable configuration of metasurface loaded slot antenna

In this article, a wideband two dimensional (2D) beam-steerable antenna structure is presented. The proposed structure is based on a radially gradient hybrid metasurface (RGHMS) illuminated through a slot antenna. The half aperture of the RGHMS comprises of a gradient phase profile topology, while its other half aperture consists of a constant phase profile configuration. The slot antenna possessing the bidirectional radiation pattern is printed on a relatively thin substrate, which operates over a wide bandwidth of 1420 MHz (15.10%). The placement of RGHMS tilts the main beam of slot antenna by 15° away from normal direction. Further, in-plane movement of MS provides beam steering in both elevation and azimuth planes, with a conical region of an apex angle of 30°. Apart from the beam steering capability, the placement of RGHMS in front of slot antenna also enhances the overall bandwidth and gain by 360 MHz and 5 dB, respectively. Thus, a wide band beam steering configuration with the impedance bandwidth of 1780 MHz (18.85%) is obtained. In order to investigate the frequency dependent beam tilting capability of the RGHMS in the elevation plane, a detailed analysis is carried out using the principle of refraction.

Miniaturized CPW-Fed Planar Monopole Antenna for Multi-band WLAN/WiMAX Wireless Applications

To incorporate two different communication standards in a single device, a miniaturized dual-band planar monopole antenna is presented in this paper. The proposed antenna is formed by a CPW feed line and a rectangular ring monopole with a vertical strip. The designed antenna has a small overall size of 19 mm Ž 36 mm Ž 1.6 mm. A prototype of the proposed antenna which was fabricated and measured to validate the design shows a good agreement between the simulation and the experiment. The measured results indicate that the antenna has the impedance bandwidths of 650 MHz (2.30-2.95 GHz) and 2460 MHz (3.40-5.86 GHz) at the first and second bands, respectively with a reflection coefficient less than - 10 dB covering all the WLAN bands (2.4/5.2/5.8 GHz) and WiMAX bands (2.6/3.5/5.5 GHz). In addition, the nearly omni-directional and bi-directional radiation patterns are also achieved in both H- and E-planes, respectively. It is also noticeable that a good antenna gain over both operating bands has been obtained. There- fore, this simple compact planar monopole antenna with multi-band characteristics is well suitable for WLAN and WiMAX wireless communication applications. Details of the proposed antenna design and both simulated and experimental results are analyzed and discussed.

Microstrip Sierpinski fractal carpet for slot antenna with metamaterial loads for dual-band wireless application

The compact microstrip antennas with the dual-band characteristic and reconfigurable qualification have been noticed and investigated in this paper. We have developed the slot microstrip antenna with Sierpinski carpet and Minkowski formations and then the metamaterial loads are placed on this antenna in the slot area. The reflection/transmission method has considered to obtain the permittivity and permeability of the split ring resonator (SRR) as a metamaterial. Finally, we show that by using some junction in the metamaterial layer, we can obtain reconfigurable characteristic. Both antennas have dual-band characteristic where the first antenna has two resonances at 3.2 and 4.5 GHz and in the second antenna by altering the metamaterial layer both resonances are occurring at 3.5 and 5.8 GHz. We show that the antenna has two resonance frequencies that matched with the metamaterial Double Negative (DNG) characteristic. Both antennas are printed on FR-4 also we compared measurement and simulation results together. Aforementioned antennas cover the main wireless, WiMAX and LTE bands with sufficient gain and high efficiency (more than 80% typically) with a bi-directional radiation pattern for the indoor application. Here, the metamaterial is used for controlling the resonances and Sierpinski carpet is developed for matching.

A compact metamaterial loaded monopole antenna with offset-fed microstrip line for wireless applications

A compact metamaterial loaded monopole antenna with offset-fed microstrip line is proposed for Universal Mobile Telecommunication System (UMTS), Worldwide interoperability for Microwave Access (WiMAX), and Wireless Local Area Network (WLAN) wireless applications. The proposed antenna is printed on a 19.18×22.64×1.6mm3 FR-4 substrate having a dielectric constant (εr) of 4.4. The antenna radiating element consists of split ring structure and CSRR for generating multiband characteristics, which is fed by offset microstrip line. A split in the outer vertical arm creates a lower order resonance at 2.1GHz and the Complementary Split Ring Resonator (CSRR) in the monopole antenna is used to generate a new resonance frequency of 3.45GHz. The precise equivalent circuit design equations are used to analyze the CSRR resonance frequency. Also, the band characteristics of a split ring structure and CSRR are enlightened in detail to verify the metamaterial property. Simulated results are verified with measured results. The measured azimuthal plane (H-Plane) exhibits omnidirectional radiation pattern and elevation plane (E-plane) represents a bidirectional radiation pattern.

Offset-fed complementary split ring resonators loaded monopole antenna for multiband operations

A miniaturized multiband monopole antenna based on rectangular-shaped Complementary Split Ring Resonators (CSRRs) with offset-fed microstrip line is proposed for Global System for Mobile Communication (GSM) and Wireless Local Area Network (WLAN) applications. The proposed antenna is fabricated on a FR-4 substrate having a dielectric constant (ɛr) of 4.4 within a small size of 19.18×22.64×1.6mm3. CSRRs in the monopole antenna create a multiband characteristics and bandwidth improvement, which is analyzed by use of the precise quasi-static design equations and electromagnetic simulation software (HFSS version 13). By selecting a proper offset-fed microstrip line, it is capable to achieve 50Ω characteristic impedance and good impedance matching. The parameter extraction procedure of the metamaterial property of the CSRRs is enlightened in detail, by which the negative permittivity existence and the new resonance frequencies are verified. Simulated and measured result coincides with each other. The measured H-Plane (azimuthal plane) exhibits omnidirectional radiation pattern and E-plane (elevation plane) shows a dipole like bidirectional radiation pattern. The proposed antenna has adequate advantages, including simple design, small size, lower return loss and capable of multiband operations.

A Nonbalancing End-Fire Microstrip Dipole With Periodic-Offset DSPSL Substrate

A nonbalancing microstrip dipole with end-fire capability is presented. The proposed antenna consists of a simple microstrip-fed dipole with a periodic-offset double-sided parallel-strip line (DSPSL) substrate, which is used to replace the balun of a conventional end-fire antenna. The periodic-offset DSPSL substrate exhibits phase shift characteristics and excites the odd mode of the microstrip dipole. A director and a truncated ground are used to increase the directivity of the antenna. After placing the DSPSL, the bidirectional radiation pattern is converted to a unidirectional one. The measured and simulated results indicate that the antenna operates at 2.4 GHz. End-fire directional radiation patterns are obtained with this novel periodic substrate. When compared with the original design of the microstrip dipoles, the proposed microstrip dipole uses the periodic-offset DSPSL substrate to replace the balun. The front-to-back ratio is about 10 dB. The design method of the end-fire antenna is a new technique and can be easily applied in other antennas.

Bidirectional same‐sense circularly polarized antenna using slot‐coupled back‐to‐back patches

ABSTRACTIn this letter, a dual‐patch antenna with bidirectional circular polarization of the same sense is proposed for coal mine and tunnel communications and positioning systems. The proposed antenna consists of two back‐to‐back patches with a common ground plane. We only feed one patch on the front side by microstrip feeding line, and the energy is coupled to the other patch on the back side through a slot, which is etched on the common ground. By properly truncating the corners of the dual patches, bidirectional radiation pattern is achieved with the right‐hand circular polarization on both front and back sides. Compared to previous designs for the same purpose, the proposed antenna is with a compact structure using only two layers of substrate and without using complex feeding networks, benefiting from the merits of small dimension, low cost, and easy fabrication. We have built the antenna prototype and taken the measurement. The measured impedance bandwidth for S11&lt;−10 dB is 90 MHz (2.44–2.53 GHz), and the measured 3‐dB axial‐ratio bandwidth is 20 MHz (2.455–2.475 GHz), agreeing well with the simulated results. The measured peak right hand circularly polarization gains are 3.70 dBic and 3.09 dBic for front and back directions. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:645–648, 2017

Wideband antenna for 4G MIMO applications

ABSTRACTA small, wideband, multiple‐input‐multiple‐output antenna is presented for 4G long term evolution (LTE) applications. The proposed antenna consists of a vertically polarized wideband stepped slot, as well as a horizontally polarized narrowband, uniform slot, integrated on a single substrate and fed by two ports. A prototype of the proposed antenna was designed, fabricated, and measured. The stepped slot antenna achieves an enhanced bandwidth of 122% from 0.77 GHz to 3.12 GHz, covering the 2G, 3G, and 4G bands. The narrowband slot achieves a bandwidth of 35% from 2.11 GHz to 3.01 GHz, covering the 4G band frequencies only. The isolation between the two slots is greater than 21 dB over the entire band of interest. The radiation pattern of the wideband slot in the horizontal plane is omnidirectional in nature while the narrowband slot exhibits a bidirectional radiation pattern in the horizontal plane. The proposed antenna is suitable for indoor, ceiling‐mount, microcell 4G LTE applications. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:601–604, 2017

A Printed Tree Fractal Based Cross Slot Antenna for 2.45GHz

Fractal based structures have been widely used in numerous antenna designs for several applications. In this paper, a printed tree fractal based cross slot antenna operating at 2.45GHz frequency is presented. The slot is in the form of a modified fractal tree structure etched on the ground plane. The slot has been fed electromagnetically by using a microstrip transmission line etched on the back side of the substrate. The printed tree fractal based cross slot antenna resonates at 2.45GHz with bidirectional radiation pattern.

A triple band circular polarized monopole antenna for GNSS/UMTS/LTE

ABSTRACTA circularly polarized Y‐shaped monopole antenna with L‐shaped slot loaded ground‐plane is proposed in this letter. The multi‐band operation is achieved due to the resonances of asymmetrical monopole arms as well as the slot in the ground plane. The circular polarization for LTE (band‐7, 2600 MHz) is achieved by using orthogonal and out of phase currents on surface of Y shaped monopole, whereas circular polarization for GNSS and UMTS‐2100 bands is the result of interaction of currents on longer arm of Y shaped monopole and loop currents on ground, which acts as a magnetic monopole. The antenna has been designed and optimised on a low cost FR‐4 epoxy substrate. The proposed antenna exhibits impedance bandwidths of 13.1, 9.7, and 7.4% at the resonant frequencies of 1.57, 2.02, and 2.55 GHz, respectively. At these three resonances, 3 dB axial ratio bandwidths of 3.7, 4.9, and 5.06% are achieved. The antenna has dual sense circular polarization, bidirectional radiation patterns, stable gain and good efficiency in the operating bands. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:298–304, 2017

Compact Rectangular Slot Microstrip Antenna with Band-Notched Characteristics for Ultrawideband Applications

In this paper, we present an offset microstrip-fed ultrawideband antenna with band notch characteristics.The antenna structure consists of rectangular radiating patch and ground plane with rectangular shaped slot, which increases impedance bandwidth upto 117.73%(2.9-11.2GHz).A new modified U slot is etched in the radiating patch to create band-notched properties in the WiMAX (3.33.7GHz) and C-band satellite communication (3.7-4.15GHz).Furthermore, parametric studies have been conducted using EM simulation software CADFEKO suite(7.0) and optimized with stable radiation pattern which satisfied UWB requirement for VSWR<2.A prototype of antenna is fabricated on 1.6mm thick FR-4 substrate with dielectric constant of 4.4 and loss tangent of 0.02.The designed antenna exhibits bidirectional and omni directional radiation patterns along E and H-plane with stable gain and efficiency over entire operating band except notch frequency band. Simulated results are in good agreement with the measured results of the proposed antenna which makes it a good candidate for UWB application.

Pattern Reconfigurable Antenna Array With Circular Polarization

A design for arrays with beam-steering capability in the azimuthal plane is described. The array is a four-sector antenna configuration, and each sector element can generate unidirectional radiation with circular polarization (CP). A reconfigurable $1\times4$ power divider with broadband operation is designed and used to excite the sector elements. By controlling PIN diodes, the divider can offer 11 states for the four outputs, and each state is corresponding to one CP radiation pattern of the array. Prototypes for the sector array and the tunable divider are, respectively, constructed, and the experimental results of the integrated structure demonstrate that, in addition to the beam-steering capability, the array can also generate bidirectional and omnidirectional radiation patterns between 1.9 and 2.3 GHz. Moreover, these steerable beams and radiation patterns have a cross polarization of less than $-18$ dB for all azimuthal angles.

Low-profile U-shaped DRA for ultra-wideband applications

In this paper, a microstrip-fed U-shaped dielectric resonator antenna (DRA) is simulated, designed, and fabricated. This antenna, in its simple configuration, operates from 5.45 to 10.8 GHz. To enhance its impedance bandwidth, the ground plane is first modified, which leads to an extended bandwidth from 4 to 10.8 GHz. Then by inserting a rectangular metallic patch inside the U-shaped DRA, the bandwidth is increased more to achieve an operating band from 2.65 to 10.9 GHz. To validate these results, an experimental antenna prototype is fabricated and measured. The obtained measurement results show that the proposed antenna can provide an ultra-wide bandwidth and a symmetric bidirectional radiation patterns. With these features, the proposed antenna is suitable for ultra-wideband applications.

A compact wideband monopole antenna fed by coplanar waveguide

A compact wideband printed antenna fed by coplanar waveguide (CPW) is presented in this paper. The wideband characteristic is achieved by coupling three monopole resonant modes of the proposed antenna. The proposed antenna is built and simulated to verify the design strategy. A wide impedance bandwidth of 100.5% (1.7866-5.3953 GHz) with S11< - 10 dB is achieved. The proposed antenna has stable performance, including bi-directional radiation pattern and gain. It also shows the merits of low cost and simple structure.