An Accurate Method of Adjusting the Resonant Frequency of Defected Microstrip Structure

2012 ◽  
Vol 588-589 ◽  
pp. 125-128
Author(s):  
Dan Cheng ◽  
Hong Cheng Yin ◽  
Hong Xing Zheng
Keyword(s):  
Resonant Frequency ◽  
Microstrip Line ◽  
Accurate Method ◽  
Property A ◽  
Rejection Level ◽  
Measurement Results ◽  
Lower Insertion Loss ◽  
Line Network ◽  
Microstrip Structure ◽  
Good Agreement

An adjustable defected microstrip structure is discussed in detail in this paper. To obtain a better bandstop property, a simple U-shaped slot is etched in the center of microstrip line, the lower insertion loss in the passband and higher rejection level has been exhibited. The resonant frequency is extracted using transmission line network analysis. At the same time, an accurate method of adjusting the resonant frequency is proposed to match the designed resonant frequency exactly. A fabricated sample has been tested to verify the design. Measurement results are in very good agreement with simulations.

Reconfigurable bandstop filter using active frequency selective surface, design and fabrication

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamed Babaei ◽  
Seyyed Amir Gohari
Keyword(s):  
Resonant Frequency ◽  
Band Gap ◽  
Frequency Selective Surface ◽  
Pin Diodes ◽  
Frequency Shifts ◽  
Surface Design ◽  
Turn On ◽  
Measurement Results ◽  
Bandstop Filter ◽  
Good Agreement

Abstract In this paper a novel FSS array is proposed, that provides dynamic band-gap in C-band. Inside the band-gap, the FSS acts as a bandstop filter. Outside the band-gap the amplitude of the reflected wave from the FSS array decreases. Therefore, the outside band is very useful in radar cross section (RCS) reduction. In this paper, at first a new FSS unit cell is designed, then in order to achieve the maximum bandwidth (1.2 GHz), dimensions of the cell are optimized. In the next step, the FSS cell is equipped with PIN diodes. Turning the diodes ON or OFF, shifts the resonant frequency of the band-gap electronically. When diodes are OFF, the resonant frequency and −10 dB bandwidth of the FSS are 5.23 and 0.9 GHz respectively. When the diodes turn ON, the resonant frequency shifts to 4.75 GHz over a bandwidth of about 1 GHz. While the band-gap is shifted dynamically, the bandwidth is kept wide, which is the novelty of this paper. In order to validate the design process, an array of active cells consisting of 128 pin diodes was designed, fabricated and then tested. Finally, the simulation and measurement results are compared with each other and a good agreement is observed between them.

scholarly journals A New Planar Multiband Antenna for GPS, ISM and WiMAX Applications

2017 ◽  
Vol 7 (4) ◽  
pp. 2018 ◽  
Author(s):  
I. Zahraoui ◽  
A. Errkik ◽  
M. C. Abounaima ◽  
A. Tajmouati ◽  
L. E. Abdellaoui ◽  
...  
Keyword(s):  
Radiation Pattern ◽  
Patch Antenna ◽  
Input Impedance ◽  
Microstrip Line ◽  
Ground Plane ◽  
Ground Structure ◽  
Entire Area ◽  
Multiband Antenna ◽  
Measurement Results ◽  
Good Agreement

In this paper a design of a new antenna with modified ground plane is validated for multiband applications. The proposed modified ground structure is incorporated with a patch antenna to boost the performance. The antenna’s entire area is 59.5x47mm<sup>2</sup> and is printed on an FR-4 substrate and fed by a 50 Ohm microstrip line.  This structure is validated in the GPS (1.56-1.58 GHz) band at 1.57 GHz, in the ISM (2.43-2.49 GHz) band at 2.45GHz and in the WiMAX (3.50-3.56 GHz) band at 3.53 GHz. These three frequency bands have good matching input impedance for, S11≤-10 dB. The antenna presents a good performance in terms of radiation pattern, and it is designed, optimized, and miniaturized by using CST-MW whose results are compared with other solvers HFSS and ADS. The results obtained by the use of the three EM solvers are in good agreement. After realization, we have tested and validated this antenna. The measurement results of the antenna present a good agreement with the numerical results.

Multiband Triple L-Arms Patch Antenna with Diamond Slot Ground for 5G Applications

2021 ◽  
Vol 36 (3) ◽  
pp. 302-307
Keyword(s):  
Computer Simulation ◽  
Resonant Frequency ◽  
Data Transmission ◽  
Patch Antenna ◽  
Microstrip Line ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Microstrip Technology ◽  
Good Agreement

This paper reported a pioneering 5G multiband microstrip line fed patch antenna for IoT, wireless power transfer (WPT) and data transmission. The proposed antenna is accomplished using a triple L-arms patch antenna responsible for the multiband response. A diamond-shaped ground slot is added to control and increase the bandwidth of the resonant frequency. The antenna is designed to resonate at 10, 13, 17 and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45 and 4.3 GHz respectively. The proposed antenna is fabricated using microstrip technology with total area of 16.5x16.5 mm2. The 5G multiband antenna has sufficient realized gain of 4.95, 5.72, 4.94 and 7.077 dB respectively. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology). Measurements show good agreement with simulations in all frequencies of operation.

Split-ring resonator-based compact microstrip antenna

2019 ◽  
Vol 33 (04) ◽  
pp. 1950043
Author(s):  
Linpeng Li ◽  
Shengze Ye ◽  
Jianchun Xu ◽  
Yanan Hao ◽  
Limin Guo ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Microstrip Antenna ◽  
Ring Resonator ◽  
Split Ring Resonator ◽  
Microstrip Antennas ◽  
Split Ring ◽  
Influencing Mechanism ◽  
Low Profile ◽  
Measurement Results ◽  
Good Agreement

Compact microstrip antennas based on split-ring resonator (SRR) structure are proposed and fabricated in this paper. The resonant frequency of the antennas is discussed upon different geometric structures. The influencing mechanism of the antenna parameters on resonant frequency is analyzed. The analytical and experimental analyses are carried out and proved that the resonant frequency can be controlled from 13.5 GHz to 17.2 GHz by tuning some of the crucial parameters. A good agreement between the simulations and the measurement results suggests that the proposed antenna can be designed at different resonant frequencies while maintaining a small-size, low-profile structure and good performance.

scholarly journals A Band-Notched Antenna With Two Radiation Zeros Using Grounded Coplanar Waveguide Filter for 2.4/5 GHz WLAN Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Min Li ◽  
Feng Xu
Keyword(s):  
Coplanar Waveguide ◽  
High Gain ◽  
Split Ring Resonator ◽  
Dipole Antenna ◽  
Ultra Wideband ◽  
Measurement Results ◽  
Feeding Structure ◽  
5 Ghz ◽  
Microstrip Structure ◽  
Good Agreement

In this article, a band-notched dual-polarized crossed dipole antenna is proposed for 2.4/5 GHz WLAN applications. The proposed antenna works on the WLAN 2.4-GHz (2.4–2.48 GHz) and 5-GHz (5.15–5.85 GHz) bands for a VSWR &lt;2 with two radiation zeros within 3.4–3.6 GHz. First, an ultra-wideband crossed dipole antenna with an operating frequency of 2.4–5.8 GHz is designed using the grounded coplanar waveguide (GCPW) feeding structure. Second, a miniaturized defected microstrip structure (DMS) is embedded in the GCPW feeding strip to form a stopband behavior with a radiation zero. Finally, combining with the design of a C-shaped split ring resonator (SRR) on the arms of the dipole antenna, a band notch (3.4–3.6 GHz) with two radiation zeros can be realized. These two radiation zeros can be adjusted independently to achieve a wide stopband performance. As a result, compared with the original ultra-wideband dipole antenna, the realized gains of the proposed antenna in the 3.4–3.6 GHz range are all suppressed from 8 dBi to less than −8 dBi. The proposed antenna can realize the stable unidirectional radiation pattern and a high gain of around 7 dBi in the lower band and 8.5 dBi in the higher band of WLAN. As a demonstration, the proposed antenna is fabricated and measured, and the measurement results are in good agreement with the simulation results.

scholarly journals A balanced-to-balanced directional coupler based on branch-slotline coupled structure

Frequenz ◽  
2020 ◽  
Vol 74 (11-12) ◽  
pp. 427-433
Author(s):  
Yaxin Liu ◽  
Feng Wei ◽  
Xiaowei Shi ◽  
Cao Zeng
Keyword(s):  
Directional Coupler ◽  
Return Loss ◽  
Design Method ◽  
Differential Mode ◽  
Arbitrary Power ◽  
Measurement Results ◽  
Transition Structures ◽  
Coupled Structures ◽  
Better Than ◽  
Good Agreement

AbstractIn this paper, a balanced-to-balanced (BTB) branch-slotline directional coupler (DC) is firstly presented, which can realize an arbitrary power division ratios (PDRs). The coupler is composed by microstrip-to-slotline (MS) transition structures and branch-slotline coupled structures. The single-ended to balanced-ended conversion is simplified and easy to implemented by the MS transition structures, which intrinsically leads to the differential-mode (DM) transmission and common-mode (CM) suppression. Moreover, the different PDRs which are controlled by the widths of branch-slotlines can be achieved. In order to verify the feasibility of the proposed design method, two prototype circuits of the proposed coupler with different PDRs are fabricated and measured. The return loss and the isolation of two designs are all better than 10 dB. Moreover, the CM suppressions are greater than 35 dB. A good agreement between the simulation and measurement results is observed.

Modeling of Discrete Tip Injection in a Two-Dimensional Streamline Curvature Method

2012 ◽  
Author(s):  
Roland Matzgeller ◽  
Richard Pichler
Keyword(s):  
Rotating Stall ◽  
Streamline Curvature ◽  
Measurement Results ◽  
Compressor Design ◽  
Multistage Compressor ◽  
Physical Effects ◽  
Tip Injection ◽  
Stability Enhancement ◽  
Good Agreement ◽  
Streamline Curvature Method

Fluid injection at the tip of highly loaded compressor rotors is known to be effective in suppressing the onset of rotating stall and eventually compressor instability. However, using such stability enhancement methods in a multistage compressor might not only stabilize certain stages but has also an impact on radial and axial matching. In order to account for tip injection during the early stages of compressor design, this paper focuses on the development of a method to model the physical effects underlying tip injection within a streamline curvature method. With the help of system identification it could be shown that a rotor subject to the discrete jets of tip injection adapts to the varying flow conditions according to a first order model. This information was used to generate a time-dependent input for the steady equations used with a streamline curvature method and eventually to model the unsteady response of the rotor to tip injection. Comparing the results obtained with the enhanced streamline curvature model to measurement results, good agreement could be shown which raised confidence that the influence of tip injection on axial and radial matching was sufficiently captured.

scholarly journals Prediction of Dynamic Stability Using Mapped Chebyshev Pseudospectral Method

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jae-Young Choi ◽  
Dong Kyun Im ◽  
Jangho Park ◽  
Seongim Choi
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Pseudospectral Method ◽  
Accurate Method ◽  
Spectral Approach ◽  
Fourier Pseudospectral Method ◽  
Chebyshev Pseudospectral Method ◽  
Fourier Pseudospectral ◽  
Chebyshev Pseudospectral ◽  
Good Agreement

A mapped Chebyshev pseudospectral method is extended to solve three-dimensional unsteady flow problems. As the classical Chebyshev spectral approach can lead to numerical instabilities due to ill conditioning of the spectral matrix, the Chebyshev points are evenly redistributed over the domain by an inverse sine mapping function. The mapped Chebyshev pseudospectral method can be used as an alternative time-spectral approach that uses a Chebyshev collocation operator to approximate the time derivative terms in the unsteady flow governing equations, and the method can make general applications to both nonperiodic and periodic problems. In this study, the mapped Chebyshev pseudospectral method is employed to solve three-dimensional periodic problem to verify the spectral accuracy and computational efficiency with those of the Fourier pseudospectral method and the time-accurate method. The results show a good agreement with both of the Fourier pseudospectral method and the time-accurate method. The flow solutions also demonstrate a good agreement with the experimental data. Similar to the Fourier pseudospectral method, the mapped Chebyshev pseudospectral method approximates the unsteady flow solutions with a precise accuracy at a considerably effective computational cost compared to the conventional time-accurate method.

The Free Energy Simulation Approach to Grain Boundary Segregation In Cu-Ni

1990 ◽  
Vol 209 ◽  
Author(s):  
H. Y. Wang ◽  
R. Najafabadi ◽  
D. J. Srolovitz ◽  
R. Lesar
Keyword(s):  
Monte Carlo ◽  
Free Energy ◽  
Grain Boundary ◽  
Chemical Potential ◽  
Boundary Segregation ◽  
Configurational Entropy ◽  
Accurate Method ◽  
Increasing Temperature ◽  
Atomic Coordinates ◽  
Good Agreement

ABSTRACTA new, accurate method for determining equilibrium segregation to defects in solids is employed to examine the segregation of Cu to grain boundaries in Cu-Ni alloys. The results are in very good agreement with the ones given by Monte Carlo. This method is based upon a point approximation for the configurational entropy, an Einstein model for vibrational contributions to the free energy. To achieve the equilibrium state of a defect in an alloy the free energy is minimized with respect to atomic coordinates and composition of each site at constant chemical potential. One of the main advantages this new method enjoys over other methods such as Monte Carlo, is the efficiency with which the atomic structure of a defect, segregation and thermodynamic properties can be determined. The grain boundary free energy can either increase or decrease with increasing temperature due to the competition between energetic and configurational entropy terms. In general, the grain boundary free energy increases with temperature when the segregation is strongest.

scholarly journals Design of Broadband Compact Canonical Triple-Sleeve Antenna Operating in UHF Band

2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy
Keyword(s):  
Wireless Communication ◽  
Instantaneous Frequency ◽  
Dipole Antenna ◽  
Frequency Range ◽  
Broadband Antenna ◽  
Operating Frequency Range ◽  
Half Wave ◽  
Measurement Results ◽  
Antenna Configuration ◽  
Good Agreement

In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.

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