Printed Yagi-Uda Antenna Research Articles

RSSI Improved for LoRa Wireless Communication, Field-Tested in the Wide-Open Area

This paper presents an effective method to boost the RSSI, the received signal strength on a moving path of LoRa wireless networking without change in digital circuitry or power amplifiers. Replacing the wire antenna as the conventionally used sensor by a printed Yagi-Uda antenna as a novel one designed to have a higher gain signifies increments of the RSSI at distant positions in the LoRa system with the same battery. The electromagnetic properties of the novel antenna are given by observing its beam-patterns in the anechoic chamber following the design procedures and fabrication. And the field-test for the radio link is conducted to see the proposed antenna enhance the RSSI at positions along the street of a wide-open area for LoRa communication. The RSSI has risen by more than 10 dB at distances from 200m to 700m with DLP-RFS1280 as the LoRa device in comparison to the conventional configuration in the device.

Beam switchable radiosonde receiver antennas

In this paper, radiosonde receiver antennas are investigated as one of the most important parts of meteorological variables sounding. The specifications of the antenna is studied for receiving radiosonde signals from all directions and from different distances. The Final structure of the proposed antennas is omnidirectional antennas, which have both gains higher than 6.5 dBi and circular polarization in specific directions. Based on the polarization analysis performed, it is recommended to divide the antenna into two parts, the upper antenna elements with circular polarization (CP) and the side antennas with linear polarization (LP). By analyzing the antenna radiation pattern, we show that it is necessary to employ multiple antenna elements to implement the side antenna. For the upper antenna, two structures, namely cross-dipole antenna, and circular polarization patch antenna, are proposed. As side antennas, the patch antenna, the 3D reflector antenna, and the printed Yagi-Uda antenna are investigated at 403 MHz. The effect of various upper antennas on the side antennas is also presented. The results show that the combination of each upper antenna with the side antenna can be selected for the ground station receiver antenna. Finally, the proposed 3D reflector antenna is employed as the receiver in the practical radiosonde test to evaluate its performance. The measured received signal level confirms the appropriate performance of the proposed antenna.

A compact rectangular slot Yagi-Uda antenna for wireless applications

In this paper, a printed Yagi-Uda antenna of the dimension 30 × 30 mm2 with parameter enhancing techniques are presented. The focus is towards gain enhancement and achieving best matched condition. The proposed structure has a fractional bandwidth of 9.03% (4.3075–4.7152 GHz), 7.86% (5.5–5.95 GHz) in simulation and 12.15% (4.25–4.8 GHz), 8.92% (5.35–5.85 GHz) in measurement respectively. It has linearly increasing gain over its entire operational bandwidth and has a simulated peak gain of 3.7 dB at 4.5 GHz and 6.62 dB at 5.8 GHz. This antenna has the advantage of simple configuration, high gain and directivity and is intended to be used for wireless applications in 4.5 GHz and 5.8 GHz bands. These analyses resulted in stable performance which is very much required from a commercially viable antenna. All the necessary antenna simulations are simulated using Ansys HFSS and is validated by fabricating a model of it. The circuit analysis is also carried out on NI AWR Design Environment.

Fractal Yagi-Uda antenna for WLAN applications

This paper describes the development of a Fractal printed Yagi-Uda antenna for Wireless Local Area Network (WLAN) applications operating at 2.4 GHz frequency. In miniaturizing the dimensions of an antenna, fractal method is applied where the 1st iteration and 2nd iteration is implemented. The Computer Simulation Technology (CST) software is used as the platform to design and simulate the antenna. The substrate material used is the FR-4 board which has a dielectric constant of 5.4, the thickness of 1.6mm and tangent loss of 0.019. The antenna performance interm of the reflection coefficient, radiation pattern and gain are compared and analyzed. For the 1st iteration, 22.81% of reduction size has been achieved and 30.81% reduction of the antenna size for 2nd iteration has been achieved.

PRINTED QUASI-YAGI ANTENNAS WITH CENTER-END-FED DIPOLE DRIVER

The novel realization of printed Yagi-Uda antenna is presented in this paper. Such the aerials are widely used in the modern telecommunication and radiolocation systems. The described method uses the nontraditional center-end-fed in-phase excitation through the hybrid ring two-way power divider. This divider behaves acceptable behavior, when all the lengths and clearances between printed conductors are optimized for Russian dielectric material FAF-4. This material is the successful discovery, when the aerial is excited through the subminiature version A connector that satisfies double-sided printed circuit board realization. The simulation-derived results indicate that the proposed aerial is the fan-beam radiator. This radiator is a good candidate for the use in the novel printed planar equidistant phased arrays for various radio systems including radiolocation, radio-finder arrangements, navigation an so on.

EBG-Backed Flexible Printed Yagi–Uda Antenna for On-Body Communication

An electromagnetic bandgap (EBG) structure backed, printed Yagi-Uda antenna for on-body communication is proposed in this communication. The proposed antenna is flexible, made of copper foil tape and polyester sheet. The antenna operates at 2.4-GHz industrial, scientific and medical radio band. A printed Yagi-Uda is used to achieve high gain, endfire radiation pattern, and decreased path loss. An EBG surface is also used to reduce the frequency detuning of the antenna and specific absorption rate (SAR) while increasing the antenna gain when placed on human body. Antenna gain has been increased by 60%, and SAR has been decreased from 8.55 to 0.07 W/kg when the antenna is backed with EBG.

A printed Yagi–Uda antenna for application in magnetic resonance thermometry guided microwave hyperthermia applicators

Biological studies and clinical trials show that addition of hyperthermia stimulates conventional cancer treatment modalities and significantly improves treatment outcome. This supra-additive stimulation can be optimized by adaptive hyperthermia to counteract strong and dynamic thermoregulation. The only clinically proven method for the 3D non-invasive temperature monitoring required is by magnetic resonance (MR) temperature imaging, but the currently available set of MR compatible hyperthermia applicators lack the degree of heat control required. In this work, we present the design and validation of a high-frequency (433 MHz ISM band) printed circuit board antenna with a very low MR-footprint. This design is ideally suited for use in a range of hyperthermia applicator configurations. Experiments emulating the clinical situation show excellent matching properties of the antenna over a 7.2% bandwidth (S11 < −15 dB). Its strongly directional radiation properties minimize inter-element coupling for typical array configurations (S21 < −23 dB). MR imaging distortion by the antenna was found negligible and MR temperature imaging in a homogeneous muscle phantom was highly correlated with gold-standard probe measurements (root mean square error: RMSE = 0.51 °C and R2 = 0.99). This work paves the way for tailored MR imaging guided hyperthermia devices ranging from single antenna or incoherent antenna-arrays, to real-time adaptive hyperthermia with phased-arrays.

Pattern-Reconfigurable Printed Dipole Antenna Using Loaded Parasitic Elements

A printed dipole antenna is designed with two parasitic elements loaded by embedded resonators to provide reconfigurable patterns. The embedded resonators in the parasitic elements are loaded by varactor diodes, which change the phase and the transmission coefficient responses of the parasitic elements. This allows the parasitic elements to act as either a director, a reflector, or a neutral element. The proposed printed dipole antenna with two loaded parasitic elements acts as a printed Yagi-Uda antenna. Because the parasitic elements can act as either a director or a reflector, the directed gain can be increased, and the front-to-back ratio (FBR) may be improved up to 42 dB. It is also possible to achieve different target FBR if broadcasting is needed in two directions of the boresight. This pattern reshaping can be obtained as quickly as the diodes can change their capacitance. The antenna is designed to operate at 2.4 GHz, but this design approach can be applied to other frequency bands. The simulation and measurement results are in good agreement. © 2016 IEEE.

Design of Pattern Reconfigurable Printed Yagi-Uda Antenna

Design of Pattern Reconfigurable Printed Yagi-Uda Antenna

A Compact Dual-Band Printed Yagi-Uda Antenna for GNSS and CMMB Applications

A printed Yagi-Uda antenna with a meandered driven dipole and a concave parabolic reflector is proposed for dual-band operations of L1-band Global Navigation Satellite System (GNSS) and S-band China Mobile Multimedia Broadcasting (CMMB). The antenna is designed and fabricated on a thin dielectric substrate, and measured at 1580 MHz in the low band (L1-band) and 2645 MHz in the high band (S-band), respectively, with directivities of 6.7 and 4.9 dBi, front-to-back ratios of 13.1 and 10.3 dB, cross-polarization levels of -23.8 and -21.9 dB, bandwidths of 4.0% and 6.5%, and antenna efficiencies of -0.40 dB (91.2%) and -0.96 dB (80.2%), which are better than -1 dBi in terms of the three-dimensional (3-D) average gain. The occupied area of this dual-band antenna is the same as that of the previously proposed single-band one. With these properties, the proposed antenna is promising for combo applications of L1-band GNSS and S-band CMMB.

A NOVEL DESIGN OF FOLDED DIPOLE FOR BROADBAND PRINTED YAGI-UDA ANTENNA

In this paper, a printed wideband Yagi-Uda antenna with a novel folded dipole driver is proposed. The folded dipole driver is comprised of a folded dipole and a microstrip feedline which functions as an internal balun to mainly determine its wide impedance bandwidth. With the optimized parameters, an operating band of 1:69GHz » 2:72GHz can be obtained. Besides the folded dipole driver, the broadband printed Yagi-Uda antenna also consists of three directors and a re∞ector. Its wideband performance is mainly determined by the folded dipole driver, while the re∞ector and directors improve its performance slightly. By optimizing the geometrical parameters of the folded dipole driver, a bandwidth of 61.8% (1:53GHz » 2:93GHz) for return loss being higher than 10dB is achieved. The proposed printed Yagi-Uda antenna is realized on FR4 substrate with a measured operating bandwidth of 62% (1:51GHz » 2:94GHz), a ∞at gain (5:6dB » 7:3dB), more than 10dB front-to-back ratio and lower than i15dB cross-polarization level.

Design and Analysis of Tripple Band Koch Fractal Yagi Uda Antenna

The proposed antenna is Koch fractal printed Yagi-Uda antenna fed by SMA connector. The radiation characteristics of the antenna are simulated by CST Microwave Studio and analysed with the help of simulated results. The antenna's currents distribution becomes more uniform after being fractal, which is conducive to increase the antenna’s radiation directivity. The proposed Koch fractal Yagi-Uda antenna resonance at frequency of 7.81 GHz, 8.54 GHz and 9.42 GHz with gain of 9.67 dB, 10.4 dB and 10.61dB respectively. Parameter of antenna such as return loss, input impedance, smith chart, radiation pattern is analyzed for performance evaluation of Koch fractal Yagi-Uda antenna. DOI: http://dx.doi.org/10.11591/ijece.v3i4.2572

A Frequency Reconfigurable Printed Yagi-Uda Dipole Antenna for Cognitive Radio Applications

A frequency reconfigurable printed Yagi-Uda antenna is presented for cognitive radio applications. A 46% continuous frequency tuning bandwidth is obtained by loading the driver dipole arms and four directors with varactor diodes. This configuration allows a high-gain and an almost constant end-fire pattern to be maintained while the antenna operating frequency is tuned. A parametric study was undertaken considering the inter-director spacing, director length tapering, and reflector geometry. It was found possible over the band that the front-to-back ratio is >; 16 dB, the sidelobe level is <; -14 dB and the cross polarization levels in the principal planes are <; - 15.5 dB. From 1-dB compression point measurements, the maximum input power of the antenna with the present diodes is limited to 17.6 dBm at 700 MHz. This suggests that reconfigurable antennas which use active components should have an IIP3 specification placed on them. The frequency selective feature of the antenna makes it as an attractive user terminal antenna for fixed point-to-multipoint cognitive radio enabled broadband wireless access.

DESIGN AND ANALYSIS OF A NOVEL CPW-FED KOCH FRACTAL YAGI-UDA ANTENNA WITH SMALL ELECTRIC LENGTH

A novel Koch fractal printed Yagi-Uda antenna fed by coplanar waveguide (CPW) is proposed and analyzed. The antenna has flrst-order Koch fractal monopoles, and the monopoles' ground plane acts as the ground plane of the antenna. The radiation characteristics of the antenna are simulated by CST Microwave Studio r and explained by the simulated results. The antenna's currents distribution becomes more uniform after being fractal, which is conducive to increasing antenna's radiation directivity. The proposed Koch fractal Yagi-Uda antenna has an operating band of 885{913MHz (relative bandwidth 3.1%) with the center frequency of 900MHz. The total antenna size is 171mm £ 85mm (0.51‚ £ 0:25‚) and the length in the antenna's polarization direction is only 25% of the wavelength corresponding to the center frequency. Compared to traditional Yagi-Uda antenna, the proposed antenna can achieve a 50% miniaturization efiect.

Design and Analysis of Printed Yagi-Uda Antenna and Two-Element Array for WLAN Applications

A printed director antenna with compact structure is proposed. The antenna is fed by a balanced microstrip-slotline and makes good use of space to reduce feeding network area and the size of antenna. According to the simulation results of CST MICROWAVE STUDIO software, broadband characteristics and directional radiation properties of the antenna are explained. The operating bandwidth is 1.8 GHz–3.5 GHz with reflection coefficient less than −10 dB. Antenna gain in band can achieve 4.5–6.8 dBi, and the overall size of antenna is smaller than0.34λ0×0.58λ0. Then the antenna is developed to a two-element antenna array, working frequency and relative bandwidth of which are 2.15–2.87 GHz and 28.7%, respectively. Compared with antenna unit, the gain of the antenna array has increased by 2 dB. Thus the proposed antenna has characteristics of compact structure, relatively small size, and wideband, and it can be widely used in PCS/UMTS/WLAN/ WiMAX fields.

NOVEL PRINTED YAGI-UDA ANTENNA WITH HIGHGAIN AND BROADBAND

A high-gain and broadband printed Yagi-Uda antenna is proposed. The microstripline-to-balance microstripline technique is adopted in the feeding mode of the active dipole, which can help to realize the balanced-unbalanced transformation. The ground of the microstrip feeding line can function as a re∞ector, and both the longer re∞ector and the shorter director can also help the antenna achieve wideband. By altering the area of the substrate, the antenna gain can be efiectively improved. A printed Yagi-Uda antenna operating at 3.5GHz has been designed and manufactured. Both the simulated and measured results indicate that there is a high positive correlation between antenna gain and the substrate area extended from the front of the director, and antenna broadband characteristic would not be changed at the same time. Moreover, the impedance bandwidth of the proposed antenna can achieve 27.4%, and the maximum gain in the operating band can reach 10.6dBi.

Switchable Printed Yagi-Uda Antenna with Pattern Reconfiguration

A switchable Yagi-Uda antenna prototype with radiation pattern reconfiguration is presented in this letter. The proposed reconfigurable antenna is based on the concept of switching between the reflector and director of a Yagi-Uda antenna using a radio frequency PIN diode. As a result, the minimum/maximum radiation can be steered towards desired signals or away from interfering signals in opposite directions. The measured 10 dB impedance bandwidth and gain are 210 MHz (7%) and 8.02 dBi at 3 GHz, respectively. Details of the antenna design and its performance are described and empirically analyzed.