half-wave dipole antenna

Author(s):  
Martin H. Weik
Keyword(s):  
2021 ◽  
Vol 21 (4) ◽  
pp. 291-298
Author(s):  
Chandana SaiRam ◽  
Damera Vakula ◽  
Mada Chakravarthy

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.


2014 ◽  
Vol 94 (7) ◽  
pp. 21-23 ◽  
Author(s):  
Mohammad Tareq ◽  
Dewan Ashraful Alam ◽  
Mazidul Islam ◽  
Razin Ahmed

2019 ◽  
Vol 9 (21) ◽  
pp. 4608 ◽  
Author(s):  
Wahaab ◽  
Yahya ◽  
Shafie ◽  
Soleimani ◽  
Rostami ◽  
...  

The coupling of electromagnetic (EM) wave to nanoflooding experiments, termed EM-assisted nanoflooding has gained enormous attention in recent years. This brings about the consideration of transmitter efficiency and the propagation pattern of the ensuing EM wave, both of which depend on reservoir electromagnetic properties. However, this has not been considered in previous works, despite its potential to improve the efficiency of the process through energy maximization. Hence, this study considers the effects of reservoir EM properties on the operation of a transmitter. The EM properties of saturated reservoir rock samples were measured. Afterward, a half-wave dipole antenna was modeled in a cylindrical reservoir based on the measured EM properties. The EM propagation pattern of the antenna was simulated in a frequency range of 100 MHz—2.0 GHz using the finite element method. The antenna was found to display dual resonance (at 800 MHz and 1.3 GHz) for sandstone saturated with oil, brine and nanofluid. Application of the EM wave at resonance frequency can help increase the efficiency of EM-assisted nanoflooding.


2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Nazirah Othman ◽  
Noor Asmawati Samsuri ◽  
Mohamad Kamal A Rahim

This research evaluates the effect of human body and metallic ring in the vicinity of dipole antenna on antenna radiation pattern and Specific Absorption Rate (SAR). Homogeneous and realistic body models have been considered in the paper. Half wave dipole antenna is used as the excitation source operating at 0.9 GHz and 1.8 GHz. The metallic ring is modelled as conducting objects. The results have shown that the presence of human body near to the antenna significantly distorted the antenna radiation pattern. The antenna gain is decresed approximately 10 dB at 0.9 GH and 25 dB at 1.8 GHz in the direction of body. Nevertheless, the presence of metallic ring do not have any profound effect on antenna radiation pattern due to their size which is relatively small compared to the size of the human body. Additional metallic ring close to the human leg could alter the SAR and the effect varies depending on the size of the rings. The presence of metallic ring significantly increases the averaged 10g SAR inside the testicle by more than 20% at 1.8 GHz.


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