scholarly journals The Improvement of first Iteration Log Periodic Fractal Koch Antenna with Slot Implementation

2018 ◽  
Vol 8 (4) ◽  
pp. 2564
Author(s):  
N. S. M. Yaziz ◽  
M. K. A. Rahim ◽  
F. Zubir ◽  
N. S. Nadzir ◽  
R. Dewan ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
Digital Television ◽  
Frequency Range ◽  
Operating Bandwidth ◽  
Good Agreement

<span>In this paper, a slotted is introduced at each of the radiating elements on the 1<sup>st</sup> iteration log periodic fractal Koch antenna (LPFKA). The antenna is designed to testify the appropriate performance at UHF Digital television which operates from 4.0 GHz to 1.0 GHz. The dimension of the conventional 0<sup>th</sup> iteration LPKFA is successfully reduced by 17% with the implementation of slotted. The results show a good agreement with a stable radiation pattern across the operating bandwidth, stable gain more than 5 dBi and reflection coefficient of below -10 dB over the desired frequency range.</span>

Second Iteration of Slotted Fractal Log Periodic Dipole Antenna for UHF Digital TV Band Application

2021 ◽  
Vol 20 (3) ◽  
pp. 48-52
Author(s):  
Muhammad Hafeez Rosmin ◽  
Mohamad Kamal A Rahim ◽  
Nur Syahirah Yaziz ◽  
Muhammad Naeem Iqbal ◽  
Osman Ayop ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Radiation Pattern ◽  
High Frequency ◽  
Dipole Antenna ◽  
Digital Tv ◽  
Wet Etching ◽  
Tangent Loss ◽  
Frequency Range ◽  
Etching Technique ◽  
Good Agreement

This paper discusses the simulations and measurements of the antenna with and without slot implementation in terms of reflection coefficient (S11) and radiation pattern. The slot implementation on each of the radiating elements on the 2nd iteration log periodic fractal Koch antenna (LPFKA) was described in this paper. This method is utilised to reduce the antenna's size while also preventing the lower designated frequencies from shifting to the higher band as the iteration increases. The antenna is designed to test and observe performance in the Ultra High Frequency (UHF) band, which ranges from 0.5 GHz to 3.0 GHz. Computer Simulation Technology (CST) software is used to design and model the antenna, which was then built using the wet etching technique. The antenna's substrate is made of FR-4 laminated board with a dielectric constant of 4.6, tangent loss of 0.019, and a thickness of 1.6mm. The results demonstrate good agreement, with a steady radiation pattern over the operational bandwidth and a reflection coefficient of less than -10 dB for the frequency range of interest. The antenna is being tested with Digital TV decoder and the result is observed towards the picture of the Digital TV.

scholarly journals Design and Development of a Wideband Planar Yagi Antenna Using Tightly Coupled Directive Element

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 975
Author(s):  
Muhammad A. Ashraf ◽  
Khalid Jamil ◽  
Ahmed Telba ◽  
Mohammed A. Alzabidi ◽  
Abdel Razik Sebak
Keyword(s):  
Reflection Coefficient ◽  
Wireless Communication ◽  
Radiation Pattern ◽  
Excellent Agreement ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Yagi Antenna ◽  
Tightly Coupled ◽  
Simulation Results ◽  
Novel Concept

In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

MULTIBAND CPW-FED SLOT ANTENNA FOR WLAN/WIMAX APPLICATIONS

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Igbafe Orikumhi ◽  
Mohamad Rijal Hamid ◽  
Ali Nyangwarimam Obadiah
Keyword(s):  
Radiation Pattern ◽  
Return Loss ◽  
Coplanar Waveguide ◽  
Ground Plane ◽  
Slot Antenna ◽  
Frequency Range ◽  
Resonant Frequencies ◽  
Good Agreement

A square slot antenna fed by a coplanar waveguide (CPW) is presented in this paper. The design consist of two pairs of “F” shaped planar strips placed within a square slotted ground. The strips are used to excite multiple resonant frequencies, the strips are connected to the ground plane by means of ideal switches. The proposed antenna has achieved multiple resonant frequencies of 2.4/5.2/5.8 GHz for WLAN and 3.5/5.5 for WiMAX applications. The measured results shows a good agreement with the simulated results in terms of return loss, radiation pattern and gain. The proposed antenna is designed for the frequency range of 2 GHz to 7 GHz which makes it suitable for Bluetooth, WLAN and WiMAX applications. 

scholarly journals Rectangular Ring Antenna Excited by Circular Disc Monopole for WiMAX System

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Souphanna Vongsack ◽  
Chuwong Phongcharoenpanich ◽  
Sompol Kosulvit ◽  
Kazuhiko Hamamoto ◽  
Toshio Wakabayashi
Keyword(s):  
Radiation Pattern ◽  
Circular Disc ◽  
Impedance Bandwidth ◽  
Frequency Range ◽  
Compact Size ◽  
Ring Antenna ◽  
Parametric Studies ◽  
Simulation Results ◽  
Wimax System ◽  
Good Agreement

This research presents a rectangular ring antenna excited by a circular disc monopole (CDM) mounted in front of a square reflector. The proposed antenna is designed to cover a frequency range of 2.300–5.825 GHz and thereby is suitable for WiMAX applications. Multiple parametric studies were carried out using the CST Microwave Studio simulation program. A prototype antenna was fabricated and experimented. The measurements were taken and compared with the simulation results, which indicates good agreement between both results. The prototype antenna produces an impedance bandwidth (|S11|< −10 dB) that covers the WiMAX frequency range and a constant unidirectional radiation pattern (θ=0°and∅=90°). The minimum and maximum gains are 3.7 and 8.7 dBi, respectively. The proposed antenna is of compact size and has good unidirectional radiation performance. Thus, it is very suitable for a multitude of WiMAX applications.

scholarly journals A Tunable Beamforming Ferroelectric Lens for Millimeter Wavelength Ranges

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 180
Author(s):  
Roman Platonov ◽  
Andrey Altynnikov ◽  
Andrey Kozyrev
Keyword(s):  
Radiation Pattern ◽  
Ferroelectric Ceramic ◽  
Wide Frequency Range ◽  
60 Ghz ◽  
Frequency Range ◽  
Digital Beamforming ◽  
Millimeter Wavelength ◽  
Beam Focusing ◽  
Array Antennas ◽  
Good Agreement

The advanced design of a millimeter-wave quasi-optical beamforming device (QOBD) based on the ferroelectric ceramic was elaborated and considered. Among the advantages of the proposed design are simplicity and cost-effectiveness in contrast to conventional analog and digital beamforming devices based on array antennas. The use of ferroelectric ceramic in the QOBD design allows operating in a wide frequency range up to 100 GHz. The advanced topology of discrete radiotransparent electrodes to provide a realization of different beamforming functions such as beam focusing and beam scanning was considered. The prototype of the proposed QOBD was designed to operate at 60 GHz. The measured radiation pattern of the QOBD prototype is in good agreement with the simulated one. Measurements demonstrate decreasing of beamwidth of the primary antenna radiation pattern by the lens prototype operating in the beam focusing regime.

USP Active Absorption Basin: Absorption of Irregular Waves

2011 ◽  
Author(s):  
Mario Luis Carneiro ◽  
Pedro Cardozo de Mello ◽  
Eduardo Aoun Tannuri
Keyword(s):  
Transfer Function ◽  
Reflection Coefficient ◽  
Digital Filter ◽  
Absorption Efficiency ◽  
Irregular Waves ◽  
Frequency Range ◽  
Active Absorption ◽  
Experimental Values ◽  
Theoretical Reflection ◽  
Good Agreement

The implementation of active absorption of irregular waves in USP Active Absorption Basin is described. The algorithm control is based on the method proposed by Scha¨ffer. A digital filter is applied as time realization of a frequency domain absorption transfer function using the measurement of surface elevation at each wavemaker as the hydrodynamic feedback. Motor dynamics and delay due to signals time travel were compensated to increase the absorption efficiency. Experiments with regular and irregular waves were carried out, where the results show a good agreement between predicted theoretical reflection coefficient and experimental values. Reflection coefficient smaller than 10% were obtained for waves in the frequency range of 0.4 to 1.1 Hz.

The working standard of the unit of power of electromagnetic waves in the frequency range from 37,5 to 220 GHz

2020 ◽  
pp. 53-58
Author(s):  
A. V. Koudelny ◽  
I. M. Malay ◽  
V. A. Perepelkin ◽  
I. P. Chirkov
Keyword(s):  
Microwave Power ◽  
Electromagnetic Waves ◽  
Primary Standard ◽  
The State ◽  
Frequency Range ◽  
Working Standard ◽  
Extended Frequency Range ◽  
Effective Efficiency ◽  
Extended Frequency ◽  
Good Agreement

The possibility of using bolometric converters of microwave power from the State primary standard of the unit of power of electromagnetic waves in waveguide and coaxial paths GET 167-2017, which has a frequency range from 37,5 to 78,33 GHz, in an extended frequency range up to 220 GHz, is shown. Studies of semiconductor bolometric converters of microwave power in an extended frequency range have confirmed good agreement and smooth frequency characteristics of the effective efficiency factor of the converters. Based on the research results, the State working standard of the unit of power of electromagnetic waves of 0,1–10 mW in the frequency range from 37,5 to 220 GHz 3.1.ZZT.0288.2018 was approved. The technical characteristics of the working standard of the unit of power of electromagnetic oscillations in an extended frequency range from 37,5 to 220 GHz are given.

Design of an interlocked four-port MIMO antenna for UWB automotive communications

2021 ◽  
pp. 1-8
Author(s):  
M. Saravanan ◽  
R. Kalidoss ◽  
B. Partibane ◽  
K. S. Vishvaksenan
Keyword(s):  
Multiple Input Multiple Output ◽  
Performance Estimation ◽  
Ultra Wideband ◽  
Antenna Element ◽  
Frequency Range ◽  
Mimo Antenna ◽  
Multiple Input ◽  
Input Multiple Output ◽  
Operating Bandwidth ◽  
Peak Gain

Abstract The design, analysis, fabrication, and testing of a four-port multiple-input multiple-output (MIMO) antenna is reported in this paper for automotive communications. The MIMO antenna is constructed using the basic antenna element exploiting a slot geometry. Two such antennas are developed on the same microwave laminate to develop a two-port MIMO antenna. Two such microwave laminates are interlocked to create the four-port MIMO scheme. The most distinct feature of the proposed architecture is that the inter-port isolation is well-taken care without the need for an external decoupling unit. The four-port MIMO antenna has an overall volume of 32 × 15 × 32 mm3. The prototype MIMO antenna is fabricated and the measurements are carried out to validate the simulation results. The antenna offers ultra-wideband (UWB) characteristics covering the frequency range of 2.8–9.5 GHz. The average boresight gain of the antenna ranges from 3.2 to 5.41 dBi with the peak gain at 8 GHz. The simulated efficiency of the antenna is greater than 73% within the operating bandwidth. The MIMO parameters such as envelope correlation coefficient, diversity gain, and mean effective gain are evaluated and presented. The appropriateness of the proposed antenna for deployment in the shark fin housing of the present-day automobiles is verified using on-car performance estimation.

Optical Vibration and Acceleration Sensor With a Silicon Cantilever

1999 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Katsuhisa Toshima ◽  
Harunobu Satoh
Keyword(s):  
Simple Model ◽  
Optical Fiber ◽  
Resonance Frequency ◽  
Acceleration Sensor ◽  
Frequency Range ◽  
Silicon Cantilever ◽  
All Optical ◽  
New Type ◽  
Good Agreement ◽  
Optical Vibration

Abstract A new type all optical vibration and acceleration sensor using the combination of micromachined Si cantilever and optical fiber is proposed, and its fundamental characteristics are demonstrated. The light emitted from bulb-lens set into the V-groove is reflected at the reflector formed on the Si cantilever and then recoupled into the bulb-lens. Several sensors with different length (0.64–6.0 mm long) of the Si cantilever are fabricated to compare the theoretical resonance frequency fr obtained from the simple model and experimental ones. They had good agreement. From the sensing principle the sensing frequency range of the vibration is suitable below the fr of the Si cantilever of the sensor.

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