scholarly journals Design and Implementation a Non-uniform Helical Antenna in Frequency Range of 450–850 MHz for Ultra-high-frequency Television Application

2019 ◽  
Vol 3 (2) ◽  
pp. 75-79
Author(s):  
Firas Muhammad Zeki ◽  
Adil Hussein Mohammed Al-Dalawie

In a domestic region, the people are living inside cities, they complaining from the weak of local TV broadcasting signals in frequency range of 450–850 MHz, in this paper try to get a solution by increase the gain antenna by design new antenna have a wideband and high gain compare with antennas are available in the local market. A non-uniform helical antenna designed using helical antenna calculator according to equations then implemented and measured the radiation pattern and gain of antenna, then compare with commercial loop antenna gain found increase in received power about 10–12 dB more than loop antenna gain. The results of measurement applied in Matlab program to draw the pattern of the antenna.

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jelena Lj. Dinkić ◽  
Dragan I. Olćan ◽  
Antonije R. Djordjević ◽  
Alenka G. Zajić

We present a design of a high-gain quad array of nonuniform helical antennas. The design is obtained by optimization of a 3-D numerical model of four nonuniform helical antennas placed above a ground plane, including a model of a feeding network, utilizing the method of moments with higher-order basis functions. The gain of one optimal nonuniform helical antenna can be about 2.5 dB higher than the gain of a uniform helical antenna of the same axial length. Creating a 2×2 array further increases the gain up to about 6 dB. The resulting quad array fits into a box whose dimensions are 2.5×3.3×3.3 wavelengths, and the gain in the main radiating direction is about 20.5 dBi in the frequency range from 0.9 GHz to 1.1 GHz. The design is verified by measurements of a prototype of the quad array.


Author(s):  
Mohd Ezwan Bin Jalil ◽  
Mohamad Kamal A. Rahim ◽  
Noor Asmawati Samsuri ◽  
Sunti Tuntrakool

This paper aims to produce a low profile, wideband, and high gain antenna for chipless RFID tag readers.  A miniaturized and wideband printed Log-Periodic Second Series Koch Dipole Array (LPSSKDA) with eleven elements operating over 0.8 GHz-3.2 GHz is designed using the FR4 board. The single LPSSKDA antenna, which acts as the chipless RFID reader antenna having gain between 5.2 and 6.1 dBi and frequency range from 1-3 GHz. A double element of the LPSSKDA antenna is proposed for improving the antenna gain to 6.9-7.9 dBi over the frequency range. The antenna is fabricated to validate the simulation and measurement results in terms of reflection coefficient, radiation pattern, and surface current distribution.


2019 ◽  
Vol 9 (15) ◽  
pp. 3157 ◽  
Author(s):  
O ◽  
Jin ◽  
Choi

In this paper, we propose a compact four-port coplanar antenna for cognitive radio applications. The proposed antenna consists of a coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna and three inner rectangular loop antennas. The dimensions of the proposed antenna are 42 mm × 50 mm × 0.8 mm. The UWB antenna is used for spectrum sensing and fully covers the UWB spectrum of 3.1–10.6 GHz. The three loop antennas cover the UWB frequency band partially for communication purposes. The first loop antenna for the low frequency range operates from 2.96 GHz to 5.38 GHz. The second loop antenna is in charge of the mid band from 5.31 GHz to 8.62 GHz. The third antenna operates from 8.48 GHz to 11.02 GHz, which is the high-frequency range. A high isolation level (greater than 17.3 dB) is realized among the UWB antenna and three loop antennas without applying any additional decoupling structures. The realized gains of the UWB antenna and three loop antennas are greater than 2.7 dBi and 1.38 dBi, respectively.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6508
Author(s):  
Jae Hee Kim ◽  
Dong-Jin Lee ◽  
Tae-Ki An ◽  
Jong-Gyu Hwang ◽  
Chi-Hyung Ahn

In general, a partially reflective surface (PRS) is mainly used to increase the gain of an antenna; some metallic objects placed on the PRS degrades the antenna performance because the objects change the periodic structure of the PRS. Herein, we propose a multifunctional PRS for smart block application. When a passenger passes over a smart block, the fare can be simultaneously collected and presented through the LED display. This requires high gain antenna with LED structure. The high gain characteristic helps the antenna identify passengers only when they pass over the block. The multifunctional PRS has a structure in which an LED can be placed in the horizontal direction while increasing the antenna gain. We used the antenna’s polarization characteristics to prevent performance deterioration when LED lines are placed in the PRS. We built the proposed antenna and measured its performance: At 2.41 GHz, the efficiency was 81.4%, and the antenna gain was 18.3 dBi. Furthermore, the half-power beamwidth was 18°, confirming a directional radiation pattern.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Syed Mushhad Mustuzhar Gilani ◽  
Muhammad Tamur Sultan ◽  
Zeng Shuai ◽  
Asif Kabir

This study aimed to explore a metallic striped grid array planar antenna, analyze it numerically in terms of its parameters, and optimize it for best performance. It may be an appropriate candidate for long-range point-to-point connectivity in wireless sensor networks. Antenna gain and frequency impedance bandwidth are two important performance parameters. For an efficient antenna, its gain should be high while maintaining operating bandwidth wide enough to accommodate the entire frequency range for which it has been designed. Concurrently, antenna size should also be small. In this study, antenna dimensions were kept as small as possible without compromising its performance. Its dimensions were 300 mm × 210 mm × 9.9 mm, which made it compact and miniature. It had a maximum gain of 16.72 dB at 2.45 GHz and maximum frequency impedance bandwidth of 7.68% relative to 50 Ω. It operated across a frequency band ranging from 2.38 GHz to 2.57 GHz, encapsulating the entire ISM 2.4 GHz band. Its radiation efficiency remained above 93% in this band with a maximum of 98.5% at 2.45 GHz. Moreover, it also had narrow HPBWs in horizontal and vertical planes having values of 18.52° and 31.25°, respectively.


2020 ◽  
Vol 10 (24) ◽  
pp. 8826
Author(s):  
Luigi Melchiorre ◽  
Ilaria Marasco ◽  
Giovanni Niro ◽  
Vito Basile ◽  
Valeria Marrocco ◽  
...  

Through the years, inspiration from nature has taken the lead for technological development and improvement. This concept firmly applies to the design of the antennas, whose performances receive a relevant boost due to the implementation of bio-inspired geometries. In particular, this idea holds in the present scenario, where antennas working in the higher frequency range (5G and mm-wave), require wide bandwidth and high gain; nonetheless, ease of fabrication and rapid production still have their importance. To this aim, polymer-based 3D antennas, such as Dielectric Resonator Antennas (DRAs) have been considered as suitable for fulfilling antenna performance and fabrication requirements. Differently from numerous works related to planar-metal-based antenna development, bio-inspired DRAs for 5G and mm-wave applications are at their beginning. In this scenario, the present paper proposes the analysis and optimization of a bio-inspired Spiral shell DRA (SsDRA) implemented by means of Gielis’ superformula, with the goal of boosting the antenna bandwidth. The optimized SsDRA geometrical parameters were also determined and discussed based on its fabrication feasibility exploiting Additive Manufacturing technologies. The results proved that the SsDRA provides relevant bandwidth, about 2 GHz wide, and satisfactory gain (3.7 dBi and 5 dBi, respectively) at two different frequencies, 3.5 GHz and 5.5 GHz.


2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Maisarah Abu ◽  
Siti Adlina Md Ali ◽  
Siti Normi Zabri

This paper investigates the performances of dipole antenna incorporated with and without 8 CBU AMC-EBG and 8 CBU FSS at 5.8 GHz. The designs are simulated on Rogers RO 3010. Due to the flexibility of the material used as a substrate, the effect of a different angle is investigated. Both 8 CBU AMC-EBG and 8 CBU FSS act as reasonably good ground plane for the dipole antenna and help improving the realised gain and improve the radiation patterns by push the front lobe at the same time reduce the side lobes. The maximum improvements led by dipole antenna with 8 CBU AMC-EBG thus 8.543 dB of realised gain achieved and the front lobe is pushed higher and the side lobe is significantly lowered than with 8 CBU FSS. The designs of dipole antenna with 8 CBU AMC-EBG and 8 CBU FSS can be applied as high gain  atenna for Intelligent Transport System (ITS).


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