scholarly journals Implementation of double-layer loaded on octagon microstrip yagi antenna

2021 ◽  
Vol 10 (6) ◽  
pp. 3289-3296
Author(s):  
Kamelia Quzwain ◽  
Alyani Ismail ◽  
Yudiansyah Yudiansyah ◽  
Nadia Media Rizka ◽  
Aisyah Novfitri ◽  
...  
Keyword(s):  
Double Layer ◽  
Double Positive ◽  
Ism Band ◽  
Yagi Antenna ◽  
Comparison Results ◽  
Good Agreement

A double-layer loaded on the octagon microstrip yagi antenna (OMYA) at 5.8 GHz industrial, scientific and medical (ISM) Band is investigated in this paper. The double-layer consist of two double positive (DPS) substrates. The OMYA is overlaid with a double-layer configuration were simulated, fabricated and measured. A good agreement was observed between the computed and measured results of the gain for this antenna. According to comparison results, it shows that 2.5 dB improvement of the OMYA gain can be obtained by applying the double-layer on the top of the OMYA. Meanwhile, the bandwidth of the measured OMYA with the double-layer is 14.6%. It indicates that the double-layer can be used to increase the OMYA performance in term of gain and bandwidth.

A Differential UWB Quasi-Yagi Antenna with A Reconfigurable Notched Band

Frequenz ◽  
2018 ◽  
Vol 72 (9-10) ◽  
pp. 401-406 ◽  
Author(s):  
Feng Wei ◽  
Xin Tong Zou ◽  
Xin Yi Wang ◽  
Bin Li ◽  
Xi Bei Zhao
Keyword(s):  
Microstrip Line ◽  
Design Procedure ◽  
Wide Band ◽  
Impedance Bandwidth ◽  
Differential Mode ◽  
Transition Structure ◽  
Notched Band ◽  
Quarter Wavelength ◽  
Yagi Antenna ◽  
Good Agreement

Abstract A compact differential ultra-wide band (UWB) planar quasi-Yagi antenna is presented in this paper. The proposed antenna consists of a balanced stepped-impedance microstrip-slotline transition structure, a driver dipole and one parasitic strip. A wide differential-mode (DM) impedance bandwidth covering from 3.8 to 9.5 GHz is realized. Meanwhile, a high and wideband common-mode (CM) suppression can be achieved by employing the balanced stepped-impedance microstrip-slotline transition structure. It is noted that the DM passband is independent from the CM response, which can significantly simplify the design procedure. In addition, a reconfigurable sharp DM notched band from 5.6 to 6.7 GHz is generated by adding one pair of quarter-wavelength varactor-loaded short-circuited stubs adjacent to the microstrip line symmetrically. In order to illustrate the effectiveness of the design, two prototypes of the antennas are designed, fabricated, and measured. A good agreement between the simulated and measured results is observed.

An X-band gain-enhanced bidirectional antenna array using strip-loaded dielectric resonator operating in TE3δ1 mode

2020 ◽  
Vol 12 (9) ◽  
pp. 915-921
Author(s):  
Ling-Ling Yang ◽  
Yan-Hui Ke ◽  
Jian-Xin Chen
Keyword(s):  
Antenna Array ◽  
Dielectric Resonator ◽  
Side Wall ◽  
High Order Mode ◽  
Yagi Antenna ◽  
X Band ◽  
Metallic Strip ◽  
Marchand Balun ◽  
First Time ◽  
Good Agreement

AbstractA bidirectional dielectric resonator (DR) antenna array using back-to-back quasi-Yagi antenna configuration is proposed and implemented for the first time. The DR operating at higher-order TE3δ1 mode is used as a magnetic dipole, applying for the driver of quasi-Yagi antenna. Due to the high-order mode employment, the antenna gain can be enhanced. By partially loading the metallic strip on the side wall of the DR, the gain can be further enhanced. In addition, a simple dual Marchand balun is constructed for feeding the two quasi-Yagi antennas directly for bidirectional radiation. To verify the design concept, a prototype operating at the X-band is fabricated and measured. Good agreement between the simulated and measured results can be observed.

scholarly journals Circularly Polarized Omnidirectional Antenna with Dipole Core and Diagonally Adjoined Parasitic Braces for ISM Band Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Piyapong Dangkham ◽  
Sitthichai Dentri ◽  
Chuwong Phongcharoenpanich ◽  
Prayoot Akkaraekthalin
Keyword(s):  
Circular Polarization ◽  
Dipole Antenna ◽  
Experimental Results ◽  
Antenna Gain ◽  
Circularly Polarized ◽  
Ism Band ◽  
Omnidirectional Antenna ◽  
Quarter Wave ◽  
Radio Band ◽  
Good Agreement

This research proposes a circularly polarized (CP) single-fed omnidirectional dipole antenna operable in 2.45 GHz frequency for the industrial, scientific, and medical (ISM) radio band applications. The proposed antenna consisted of bisectional dipole core, a pair of quarter-wave baluns, and four diagonally adjoined parasitic braces. The bisectional dipole core was utilized to improve the antenna gain and realize omnidirectional radiation pattern, and the quarter-wave baluns were to symmetrize the current on the bisectional core. The four parasitic braces collectively generated circular polarization. In the study, simulations were conducted using CST Microwave Studio and a prototype antenna fabricated. To validate, experiments were carried out, and simulation and experimental results compared. The finding revealed good agreement between the simulation and experimental results. Essentially, in addition to achieving an antenna gain of 2.07 dBic, the proposed CP single-fed omnidirectional antenna is suited to ISM frequency band applications.

A New Metamaterial Printed Microstrip Yagi -Array Antenna for ISM band Applications

2015 ◽  
Vol 3 (4) ◽  
pp. 320-324
Author(s):  
Amalasofiah S ◽  
Preethi C
Keyword(s):  
Return Loss ◽  
Array Antenna ◽  
Ring Resonators ◽  
Cross Polarization ◽  
Split Ring ◽  
Directional Characteristic ◽  
Split Ring Resonators ◽  
Ism Band ◽  
Interference Level ◽  
Yagi Antenna

A traditional yagi antenna is used for broadband applications. A New Metamaterial Printed Microstrip Yagi -Array Antenna has been introduced here. This antenna is found to operate at 2.4GHz. The microstrip yagi-array antenna is loaded with artificial split ring resonators (SRRs) which is used for achieving the metamaterial effect in the structure. The overall circuit size of the designed antenna is 11.5*11.5*0.25mm3 with reduced cross polarization and the substrate used is FR4 epoxy with dielectric constant 4.4 which is readily available. The designed antenna achieved about 4dB of gain and it also achieved a high directional characteristic of 5-9dB in the operating band. The designed antenna had a minimum return loss of about -8dB. The achievement of narrowband width for ISM band application enhances the efficiency of the antenna at the specified band and reduces the interference level.

Effects of Materials on Formation of Double-Layered Liners Shaped Charges

2009 ◽  
Vol 79-82 ◽  
pp. 1277-1280
Author(s):  
Yu Zheng ◽  
Xiao Ming Wang ◽  
Wen Bin Li ◽  
Wen Jin Yao
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Simulations ◽  
Double Layer ◽  
Two Dimensional ◽  
Materials Properties ◽  
X Ray ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Good Agreement

In order to study the effects of liner materials on the formation of Shaped Charges with Double Layer Liners (SCDLL) into tandem Explosively Formed Projectile (EFP), the formation mechanism of DLSCL was studied. Utilizing two-dimensional finite element dynamic code AUTODYN, the numerical simulations on the mechanical phenomenon of SCDLL forming into tandem EFP were carried out. X-ray pictures were obtained after Experiments on SCDLL. Comparisons between experimental results and numerical simulation results have good agreement. It can be concluded from the results that the materials properties and configurations of both liners are crucial to the formation of tandem EFP.

The structure of the electrical double layer in the presence of adsorbed organic molecules

1961 ◽  
Vol 264 (1316) ◽  
pp. 133-144 ◽  
Keyword(s):  
Double Layer ◽  
Electrical Double Layer ◽  
Organic Molecules ◽  
Virial Equation ◽  
Differential Capacity ◽  
Free Energy Of Adsorption ◽  
High Coverage ◽  
Virial Equation Of State ◽  
Capacity Data ◽  
Good Agreement

On the model of the electrical double layer previously proposed by the author, equations are derived for the differential capacity of the metal/electrolyte interface in the presence of organic molecules. It is shown that the equations apply even when ions are specifically adsorbed. A method of calculating the amount of adsorption of the organic species from differential capacity data is outlined and applied to published results for thiourea at the mercury aqueous sodium fluoride interface. It is shown that the results are in good agreement with thermodynamic data. From the calculated adsorption d a ta it is shown that thiourea obeys a virial equation of state but that lateral electrostatic forces are probably negligible except at high coverage. The free energy of adsorption as a function of charge has been evaluated and shown to consist of an electrostatic term and a chemical term which decreases as the electron density of the mercury surface decreases.

The RELAP5 Simulation of 2″ LOCA of APEX Facility

2010 ◽  
Author(s):  
Heng Xie
Keyword(s):  
Test Facility ◽  
State University ◽  
Pressurized Water Reactor ◽  
Reduced Pressure ◽  
Pressurized Water ◽  
Sequence Of Events ◽  
Comparison Results ◽  
Integral Systems ◽  
Oregon State University ◽  
Good Agreement

The RELAP5/SCDAP Mod3.2(am5) code is employed to simulate the OSU-AP1000-05 test conducted in the Advanced Plant Experimental (APEX) test facility at Oregon State University (OSU). The APEX-1000 test facility is an one-fourth height, one-half time scale, and reduced pressure integral systems facility to simulate the Westinghouse Advanced Passive 1000 MW (AP1000) pressurized water reactor. OSU-AP1000-05 is a two-inch break at the bottom of cold leg #4 with 3 out of 4 ADS-4 valves of OSU-APEX-1000 facility. RELAP5 predictions are compared to the experimental data generated by the test. The comparison shows good agreement between the predicted and measured sequence of events of some key parameters during the transient. From the comparison results, it could be preliminary concluded that the RELAP5/SCDAP Mod3.2(am5) code are suitable to simulate the small LOCA of APEX.

Dynamics and stability analysis of a flexible liquid-filled rotor in a constant thermal environment

2021 ◽  
pp. 107754632110224
Author(s):  
Guangding Wang ◽  
Wenjun Yang ◽  
Huiqun Yuan
Keyword(s):  
Thermal Environment ◽  
Rotor System ◽  
Flexible Rotor ◽  
Rotatory Inertia ◽  
Rayleigh Beam ◽  
Comparison Results ◽  
The Stability ◽  
Spinning Speed ◽  
Thermoelastic Theory ◽  
Good Agreement

In this study, the dynamics and stability of a flexible rotor containing liquid in a constant thermal environment are investigated. According to thermoelastic theory, the thermal axial force exerted on the rotor is calculated by using the analytical method. A spinning Rayleigh beam is used as a simplified model of the rotor. Applying the Hamilton principle, the governing equation of motion for the flexible liquid-filled rotor system is derived. Using the obtained model, the stability prediction model and the critical spinning speed for the rotor system are formulated. To demonstrate the validity of the developed model, the present analysis is compared with the results reported in the previous study, and good agreement is observed from the comparison results. Finally, numerical results based on the obtained model are performed for a better understanding of the parameters including filling parameters, mode number, rotatory inertia and thermal effect on the stability, and critical spinning speed of the rotor system.

scholarly journals Coplanar Stripline-Fed Wideband Yagi Dipole Antenna with Filtering-Radiating Performance

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1258
Author(s):  
Yong Chen ◽  
Gege Lu ◽  
Shiyan Wang ◽  
Jianpeng Wang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Frequency Selectivity ◽  
Antenna Design ◽  
Initial Structure ◽  
Coplanar Stripline ◽  
Half Wavelength ◽  
Yagi Antenna ◽  
Operating Bandwidth ◽  
Good Agreement

In this article, a wideband filtering-radiating Yagi dipole antenna with the coplanar stripline (CPS) excitation form is investigated, designed, and fabricated. By introducing an open-circuited half-wavelength resonator between the CPS structure and dipole, the gain selectivity has been improved and the operating bandwidth is simultaneously enhanced. Then, the intrinsic filtering-radiating performance of Yagi antenna is studied. By implementing a reflector on initial structure, it is observed that two radiation nulls appear at both lower and upper gain passband edges, respectively. Moreover, in order to improve the selectivity in the upper stopband, a pair of U-shaped resonators are employed and coupled to CPS directly. As such, the antenna design is finally completed with expected characteristics. To verify the feasibility of the proposed scheme, a filtering Yagi antenna prototype with a wide bandwidth covering from 3.64 GHz to 4.38 GHz is designed, fabricated, and measured. Both simulated and measured results are found to be in good agreement, thus demonstrating that the presented antenna has the performances of high frequency selectivity and stable in-band gain.

Simulation and Microstructure Predict during Hot Die-Forging of Cast Mg-7.0Al-0.2Zn Magnesium Alloy

2010 ◽  
Vol 152-153 ◽  
pp. 1293-1296
Author(s):  
Li Hong Wu
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Strain Distribution ◽  
Forging Process ◽  
Die Forging ◽  
Comparison Results ◽  
Hot Die Forging ◽  
Good Agreement

Employing the dies for aluminum alloy parts, the hot die-forging forming and numerical simulation of semi-continuous casting Mg-7.0Al-0.4Zn (AZ70) were carried out. It was indicated that AZ70 has a worse fluidity during forging and is consequently difficult to fill fully compared to aluminum alloys. The microstructure of the AZ70 forgings is in good agreement with the strain distribution generated by simulation, and strain distribution can predict the microstructure evolution. The comparison results can give a guideline on developing forging process and controlling forgings quality of the AZ70 alloy.

Sign in / Sign up

Export Citation Format

Share Document