Analysis of feed waveguide length influence on EM field in microwave applicator using TLM method

Milovanović, Bratislav; Joković, Jugoslav; Dimitrijević, Tijana

doi:10.2298/fuee0801065m

Cited by 2 publications

(2 citation statements)

References 10 publications

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“…According to Figures 14 and 15, the distribution of the electric field inside the cavity does not change significantly by changing the dimensions of the waveguide. However, because the waveguide width and height affect the cutoff frequency of the waveguide, the waveguide acts as a high pass filter [24], and the length (depth) of the waveguide only affects the filtering of frequencies below the cutoff frequency. Moreover, when the cutoff frequency of the waveguide is close to the operating frequency (2.45 GHz), the value of the electric field in the cavity and coal and, consequently, the rate of temperature increases inside the coal increases.…”

Section: Effect Of the Waveguide Chamber Sizementioning

confidence: 99%

Numerical Simulation and Optimization of Microwave Heating Effect on Coal Seam Permeability Enhancement

Jebelli

Mahabadi

2022

Technologies

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In coal mining operations, coalbed methane is one of the potential hazards that must be extracted to prevent an explosion of the accumulated gas and environmental pollution. One of the mechanisms is using microwave irradiation so that the thermal stress caused by microwave heating generates fractures. In this research, we investigated the most important parameters affecting the electric and thermal fields’ distribution in coal in order to identify the effective parameters that achieve the highest temperature increase rate and to reach the highest impact and efficiency of the system with the least amount of consumed energy. In this paper, using Maxwell equations, heat transfer, mass transfer and coupling them by COMSOL, we have simulated the radiation of electromagnetic field and heat in the cavity and coal, and we have also shown the temperature dispersion inside the coal. The parameters studied included the amount of coal moisture (type of coal), operating frequency, input power and heating time, location of the waveguide, the size of the waveguide and the location of the coal, and finally the parameters were re-examined in a secondary standard cavity to separate the parameters related to the size of the environment and the cavity from the independent parameters. The results of this study show that the most effective parameter on the electric and thermal fields’ distribution within coal is the size of the resonance chamber. Additionally, the results show that the moisture of 5%, the highest input power and cutoff frequency close to the operating frequency cause the highest average temperature inside the coal, but many parameters such as operating frequency, waveguide location and coal location should be selected depending on the chamber size.

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Section: Effect Of the Waveguide Chamber Sizementioning

confidence: 99%

Numerical Simulation and Optimization of Microwave Heating Effect on Coal Seam Permeability Enhancement

Jebelli

Mahabadi

2022

Technologies

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“…Amongst the available filter manufacturing technologies, rectangular waveguides are attractive in communication systems, such as radar and satellite systems, due to their ability to handle high power and have low losses [4]. In this technology, bandstop and bandpass filters can be easily implemented with properly employed feeders [5]. Filters are designed by inserting discontinuities into the E-plane or H-plane of the rectangular waveguides.…”

Section: Introductionmentioning

confidence: 99%

Design of microwave waveguide filters with effects of fabrication imperfections

Mrvić¹,

Stefanovski-Pajovic²,

Potrebić³

et al. 2017

FACTA U EE

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This paper presents results of a study on a bandpass and bandstop waveguide filter design using printed-circuit discontinuities, representing resonating elements. These inserts may be implemented using relatively simple types of resonators, and the amplitude response may be controlled by tuning the parameters of the resonators. The proper layout of the resonators on the insert may lead to a single or multiple resonant frequencies, using single resonating insert. The inserts may be placed in the E-plane or the H-plane of the standard rectangular waveguide. Various solutions using quarter-wave resonators and splitring resonators for bandstop filters, and complementary split-ring resonators for bandpass filters are proposed, including multi-band filters and compact filters. They are designed to operate in the X-frequency band and standard rectangular waveguide (WR-90) is used. Besides three dimensional electromagnetic models and equivalent microwave circuits, experimental results are also provided to verify proposed design. Another aspect of the research represents a study of imperfections demonstrated on a bandpass waveguide filter. Fabrication side effects and implementation imperfections are analyzed in details, providing relevant results regarding the most critical parameters affecting filter performance. The analysis is primarily based on software simulations, to shorten and improve design procedure. However, measurement results represent additional contribution to validate the approach and confirm conclusions regarding crucial phenomena affecting filter response.

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Analysis of feed waveguide length influence on EM field in microwave applicator using TLM method

Cited by 2 publications

References 10 publications

Numerical Simulation and Optimization of Microwave Heating Effect on Coal Seam Permeability Enhancement

Numerical Simulation and Optimization of Microwave Heating Effect on Coal Seam Permeability Enhancement

Design of microwave waveguide filters with effects of fabrication imperfections

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