scholarly journals Design of Rat-Race based Retrodirective Arrays for Backscatter Communications

2020 ◽  
Vol 2 (2) ◽  
pp. 8-13
Author(s):  
Mahalakshmi P ◽  
Vallikannu A. L.
Keyword(s):  
Dielectric Constant ◽  
Resonant Frequency ◽  
Prior Knowledge ◽  
Radiation Pattern ◽  
Communication Technology ◽  
Interesting Property ◽  
Ansys Software ◽  
Incoming Signal ◽  
S Parameters

Fast beaming tracking and security are important factors for the development of communication technology. A Retrodirective antenna (RDA) technique has been attenuated to one way of improving security. It has the interesting property of automatically responding to an incoming signal location without any prior knowledge of the direction of that source. The purpose of this paper is to design a Rat race coupler which acts as a Retrodirective mode in ANSYS. The resonant frequency of the coupler is 2.4 GHz. The Proposed Rat race couplers have been devised using the Glass Epoxy substrate (FR4) with dielectric constant (?r = 4.4). S parameters, radiation pattern, insertion and isolation losses are obtained from ANSYS software

scholarly journals Rancang Bangun Antena Mikrostrip Bowtie Pada Frekuensi 5,2 Ghz

2018 ◽  
Vol 10 (2) ◽  
pp. 15-21
Author(s):  
Aprinal Adila Asril ◽  
Lifwarda Lifwarda ◽  
Yul Antonisfia
Keyword(s):  
Dielectric Constant ◽  
Resonant Frequency ◽  
Resonance Frequency ◽  
Radiation Pattern ◽  
Microstrip Antenna ◽  
Return Loss ◽  
Microstrip Antennas ◽  
Antenna Design ◽  
Narrow Bandwidth ◽  
Simple Materials

Microstrip antennas are very concerned shapes and sizes. Can be viewed in terms of simple materials, shapes, sizes and dimensions smaller antennae, the price of production is cheaper and able to provide a reasonably good performance, in addition to having many advantages, the microstrip antenna also has its drawbacks one of which is a narrow bandwidth. In this research will be designed a microstrip antenna bowtie which works at a frequency of 5.2 GHz which has a size of 68mm x 33mm groundplane. For the length and width of 33mm x 13mm patch. This antenna is designed on a printed cicuit board (PCB) FR4 epoxy with a dielectric constant of 4.7 and has a thickness of 1,6mm. This bowtie microstrip antenna design using IE3D software. This antenna has been simulated using IE3D software showed its resonance frequency is 5.270 GHz with a return loss -23 595 dB bandwidth of 230 MHz, VSWR 1,142, unidirectional radiation pattern and impedance 43,919Ω. The results of which have been successfully fabricated antenna with a resonant frequency of 5.21 GHz with a return loss -16.813 dB bandwidth of 79 MHz, VSWR 1.368, unidirectional radiation pattern, impedance 43,546Ω and HPBW 105 °.

Stress and Vibration Analysis of Motor Back Plate in HDD

2011 ◽  
Vol 275 ◽  
pp. 97-100 ◽  
Author(s):  
Geun Sub Heo ◽  
Oh Hyun Kang ◽  
Cheol Woo Park ◽  
Sang Ryong Lee ◽  
Choon Young Lee
Keyword(s):  
Resonant Frequency ◽  
High Speed ◽  
Vibration Mode ◽  
Hard Disk Drives ◽  
Mode Analysis ◽  
Design Parameters ◽  
Disk Drives ◽  
Ansys Software ◽  
Back Plate ◽  
Plate Shape

In the present study, we have simulated stress characteristics and vibration modes in the back plate of head-stack driving motor of 2.5 inch small sized hard disk drives (HDDs). The magnets in head-stack driving motor have large magnetic fields, and therefore, the resulting large force may induce fracture and deformation in the back plate of the motor. Since the high-speed motion of head-stack motor generates high frequency vibration, we analyzed the vibration mode to avoid resonant frequency. ANSYS software was used in this study to check the deformation of back plate with the following design parameters: thickness of plate, the number of support beams, and the width of support beams. From the vibration mode analysis, we obtained a stable plate shape whose operating frequency is off the resonant frequency.

scholarly journals Estimation of S-parameters and dielectric permittivity of quartz ceramics samples in millimeter waveband

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 65-71
Author(s):  
N. A. Pevneva ◽  
D. A. Kondrashov ◽  
A. L. Gurskii ◽  
A. V. Gusinsky
Keyword(s):  
Dielectric Constant ◽  
Dielectric Permittivity ◽  
Ceramic Materials ◽  
Reflection And Transmission Coefficients ◽  
Frequency Range ◽  
Reflection And Transmission ◽  
Transmission Coefficients ◽  
Higher Order Modes ◽  
S Parameters ◽  
The Fourier Transform

A modified Nicholson – Ross – Weir method was used to determine complex parameters and dielectric permittivity of ceramic materials in the range 78.33–118.1 GHz. The measuring equipment is a meter of complex reflection and transmission coefficients, a waveguide measuring canal with a special measuring cell, consisting of two irregular waveguides and a waveguide chamber between them, which provides insignificant influence of higher-order modes. The dependences of the amplitude and phase of the reflection and transmission coefficients on frequency were obtained experimentally for fluoroplastic and three ceramic samples in the frequency range 78.33–118.1 GHz. The obtained S-parameters are processed according to an algorithm that includes their averaging based on the Fourier transform in order to obtain the values of the dielectric permittivity. Fluoroplastic was used as a reference material with a known dielectric constant. The dielectric constant of fluoroplastic has a stable value of 2.1 in the above mentioned frequency range. The dielectric constant of sample No. 1 varies from 3.6 to 2.5 at the boundaries of the range, sample No. 2 – from 3.7 to 2.1, sample No. 3 – from 2.9 to 1.5. The experimental data are in satisfactory agreement with the literature data for other frequencies taking into account the limits set by the measurement uncertainty.

scholarly journals Radiation Pattern Reconfigurable Waveguide Slot Array Antenna Using Liquid Crystal

2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongyu Shi ◽  
Jianxing Li ◽  
Shitao Zhu ◽  
Anxue Zhang ◽  
Zhuo Xu
Keyword(s):  
Dielectric Constant ◽  
Liquid Crystal ◽  
Electric Field ◽  
Radiation Pattern ◽  
Array Antenna ◽  
Antenna Element ◽  
Waveguide Slot ◽  
Radiation Direction ◽  
Coupled Resonator

In this paper, we proposed a radiation pattern reconfigurable waveguide slot array antenna using liquid crystal (LC). Together with the waveguide slot, the designed complementary electric-field-coupled resonator functions like a switch controlled by the dielectric constant of the LC, which can control the antenna element to radiate or not. Thus, the array factor and radiation pattern can be manipulated. The proposed antenna was simulated, fabricated, and measured. Its radiation direction can be reconfigured to 46° or 0° at about 15 GHz.

Qualification of Polyimide Based Coverlays for 900 MHz and 2.40 GHz Microstrip Antenna Applications

2012 ◽  
Vol 2012 (1) ◽  
pp. 001078-001080
Author(s):  
Deepukumar Nair ◽  
Glenn Oliver ◽  
Jim Parisi
Keyword(s):  
Resonant Frequency ◽  
Radiation Pattern ◽  
Microstrip Antenna ◽  
Microstrip Antennas ◽  
Frequency Detuning ◽  
Antenna Gain ◽  
Test Vehicle ◽  
Minimal Impact ◽  
Frequency Bands

Organic coverlays are required to protect microstrip circuits in most applications. The presence of coverlay can potentially influence the performance of microstrip antennas. This paper describes the qualification of polyimide based coverlays for microstrip antennas both in 900 MHz and 2.50 GHz frequency bands. An Inverted F-shaped antenna fabricated on FR-4 dielectric is used as the test vehicle and two different coverlay materials are tested with respect to key parameters like resonant frequency, S11 bandwidth, antenna gain, frequency detuning, and radiation pattern. The data presented in this paper clearly indicates polyimide materials are well suited to cover microstrip antenna circuits with minimal impact on performance.

Microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti) ceramics

1999 ◽  
Vol 14 (9) ◽  
pp. 3567-3570 ◽  
Author(s):  
Ji-Won Choi ◽  
Chong-Yun Kang ◽  
Seok-Jin Yoon ◽  
Hyun-Jai Kim ◽  
Hyung-Jin Jung ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Multiphase Materials ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

The microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti, 0 ≤ x ≤ 0.5) ceramics were investigated. In general, the ceramics prepared were multiphase materials. However, single-phase specimens having orthorhombic perovskite structure similar to CaTiO3 could be obtained in the vicinity of Sn = 0.2 to 0.3, and Ti = 0.2. As Sn concentration increased, the dielectric constant (εr) decreased and the quality factor (Q) significantly increased within the limited Sn concentration. As Ti concentration increased, the dielectric constant (εr) increased, the quality factor (Q) decreased, and the temperature coefficient of resonant frequency (τf) changed from a negative to positive value. The temperature coefficient of resonant frequency of 0 ppm/°C was realized at Ti = 0.2. The Q · fo value and εr for this composition were found to be 26100 GHz and 38.6, respectively.

Dielectric properties of La-substituted Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 ceramics

2001 ◽  
Vol 16 (7) ◽  
pp. 2053-2056
Author(s):  
X. J. Lu ◽  
X. M. Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Microwave Dielectric Properties ◽  
Present Approach ◽  
Calculated Temperature ◽  
Microwave Dielectric ◽  
La Substitution ◽  
Dielectric Ceramics

Modification of Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 dielectric ceramics was performed by up to 20 mol% La substitution for Pb and Ca. The temperature coefficient of dielectric constant was significantly reduced by the present approach, while an increased Qf factor was achieved. Good microwave dielectric properties were obtained in a composition Pb0.425Ca0.425La0.1[(Mg1/3Nb2/3)0.5Ti0.5]O3: ε = 125; Qf = 3150 GHz; calculated temperature coefficient of resonant frequency δf = +253 ppm/°C.

scholarly journals Inverted dual U slot loaded truncated microstrip patch antenna for wireless applications

2018 ◽  
Vol 7 (2.21) ◽  
pp. 151
Author(s):  
Kavitha Thandapani ◽  
Shiyamala Subramani
Keyword(s):  
Dielectric Constant ◽  
Resonant Frequency ◽  
Loss Tangent ◽  
Patch Antenna ◽  
Return Loss ◽  
Microstrip Patch Antenna ◽  
Wireless Applications ◽  
Microstrip Patch ◽  
Dielectric Constant And Loss ◽  
Circular Patch Antenna

Dual U Slot Loaded Truncated Microstrip Patch Antenna is designed for wireless applications. The proposed geometry comprised of two inverted U slots in truncated circular patch antenna operation covering 2.24 to 2.72 GHZ frequency bands are obtained. It is found that the slot and truncated is used to improve the bandwidth and return loss respectively. The resonant frequency is found to be 2.5GHZ. The bandwidth of the proposed antenna for lower and upper resonant frequency is found to be 19.2%. The proposed antenna is fed by 50Ω co-axial probe feed and simulated on Rogers RT/duroid5880 substrate.  Rogers RT/duroid 5880 substrate has dielectric constant and loss tangent of 2.2 and 0.0009 respectively. An air gap is used in this proposed design for tuning the desired frequencies and increasing the bandwidth. The antenna shows an acceptable gain of 2.1dB to 5.7dB with unidirectional pattern over the obtained frequency band. 

scholarly journals A Modified Rectangular Mid-band Microstrip Slot Antenna for WLAN, WiFi and 5G Applications

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Ajay Thatere ◽  
◽  
Sachin Khade ◽  
Vipul Lande S ◽  
◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Current Distribution ◽  
Ground Plane ◽  
Surface Current ◽  
Slot Antenna ◽  
Current Gain ◽  
Wide Bandwidth ◽  
Left And Right

A modified rectangular Microstrip slot antenna for numerous applications like WLAN, Wi-Fi 5, satellite telecommunication and 5G application is portrayed. The proposed antenna has dimension of 25×30×1.6 mm3. The structure consists of partial ground and DGS. The proposed design is embedded on FR4 lossy substrate having dielectric constant of 4.3 and thickness of 1.6 mm. Two similar inverted L shape CLLR are introduced at left and right edge of the ground plane to improve current distribution and to achieve wide bandwidth. The results like reflection coefficient, surface current, gain, directivity, VSWR, impedance and radiation pattern are found up to the mark.

scholarly journals Analysis on different shape of textile antenna under bending condition for GPS application

2020 ◽  
Vol 9 (5) ◽  
pp. 1964-1970
Author(s):  
N. I. Zaidi ◽  
M. T. Ali ◽  
N. H. Abd Rahman ◽  
M. F. Yahya ◽  
M. S. Amin Nordin
Keyword(s):  
Resonant Frequency ◽  
Radiation Pattern ◽  
Antenna Gain ◽  
Bending Angle ◽  
Antenna Performance ◽  
Textile Antenna ◽  
Human Arm ◽  
Different Shapes ◽  
Antenna Characteristics

In this paper, three antennas with different designs, which are square, circle and edgy patch (flower) were simulated and fabricated. The experiment was carried out to study the effects of bending on these three different shapes of antennas. Two bending conditions which are H-plane and E-plane were used. The antenna was designed to resonate at 1.575 GHz for GPS application and to be incorporated with human arm. Thus, the bending angle was specified to be 135o which is about the size of a typical human arm. As the paper focusing on the bending effects only, the characteristic of the bending structure was set to be equal to the air, with Ɛr=1. The antenna characteristics such as gain, resonant frequency and radiation pattern were analyzed for these three shapes of antennas. As a result, the shape of the radiating patch has significant impact on the antenna performance under bending conditions. Based on the comparison of E-plane and H-plane data, the edgy shape was found to be more affected in term of gain performance as compared to other shapes. Bending on E-plane has shown severe degradation in antenna gain performance, whereby at H-plane, significant improvement in gain was observed

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