Setup and Results of Pyramidal Microwave Absorbers Using Rice Husks

Nornikman, H.; Malek, F.; Ahmed, Manjur; Wee, F. H.; Soh, Ping Jack; Al‐Hadi, Azremi Abdullah; Ghani, Supri A.; Hasnain, Ali; Taib, Mohamad Nasir

doi:10.2528/pier10101203

Cited by 40 publications

(27 citation statements)

References 27 publications

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“…These holes were similar to an array of dielectric circular waveguides having a length that was five times the diameter of the waveguide. Both perforated absorbers had a thickness of 15 mm, which was less than the previously-designed pyramid absorber [3,25]. Figure 9 shows the two perforated, ricehusk microwave absorbers with circular holes.…”

Section: Absorber Design and Geometrical Detailsmentioning

confidence: 97%

“…Rice husks are used in many ways, including cattle feed, fuel for furnaces and gasifiers, and feedstock for chemical, paperboard, and silica industries [2]. However, its effectiveness in electromagnetic energy absorption has been proven in recent years [3]. Rice husks contain high contents of Carbon (35-37%) which is considered as a lossy non-metallic conductor.…”

Section: Introductionmentioning

confidence: 99%

“…The rice-husk absorber has been investigated by many researchers, but their main focus has been to prove its potential use as a microwave absorber in the pyramidal shape [3]. Currently, it is important to explore its practical applications in actual situations, such as in anechoic chambers.…”

Section: Introductionmentioning

confidence: 99%

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A Study of the Emc Performance of a Graded-Impedance, Microwave, Rice-Husk Absorber

Iqbal¹,

Malek²,

Ronald³

et al. 2012

PIER

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Abstract-Biomass used for energy, whether it is extracted from forest residues or agricultural waste, contributes in many areas, such as power production, the construction industry, and also as a major source of different organic and inorganic compounds in the petrochemical industry. In recent years, research has identified a very remarkable use of agricultural waste, especially rice husks, as a microwave absorber in a pyramidal shape. However, absorbers built in this shape are fragile and require a very high degree of care, especially near the access panels, doors, and high traffic areas of the anechoic facility. This paper presents the results of a detailed experimental investigation of a more-robust, new design that is based on the concept of impedance or dielectric grading of rice-husk material. The absorber was fabricated using multiple layers of rice-husk material with increasing dielectric loss along the incident wave propagation axis. This type of fabrication technique provides more robust design of the microwave, rice-husk absorber with less thickness, as compared to the geometricallytapered, pyramid, or wedge absorbers. Free-space transmission and radar cross section (RCS) methods have been used, to study the electromagnetic compatibility (EMC) performance over the frequency range of 4-8 GHz. After the receiving equipment was calibrated by the thru-reflect-line (TRL) calibration technique, the experiments were performed inside the anechoic chamber. The performance of the absorber was evaluated by incorporating the effects of circular-hole perforation, cross-polarized seams, and different metallic back plates. The proposed absorber demonstrated good performance (< −10 dB) for normal and 60 • off the normal incident angles over the frequency range of 4-8 GHz. Reflectivity performance also was found to be comparable to one of the commercially-available absorbers.

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Section: Absorber Design and Geometrical Detailsmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A Study of the Emc Performance of a Graded-Impedance, Microwave, Rice-Husk Absorber

Iqbal¹,

Malek²,

Ronald³

et al. 2012

PIER

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“…The equipment used in this measurement was a signal generator, a spectrum analyzer, a pair of coaxial cables, seven pairs of horn antennas, the reference metal and a tripod to hold the horn antennas and the reference metal [42,43]. The angle between the pyramidal microwave absorber and the horn antenna was 60 • .…”

Section: Methodsmentioning

confidence: 99%

“…The source signal is the starting point of the signal before transmission occurs. The distance between the pyramidal microwave absorber and the source of the signal source (port), Z pos , was 50 cm [32][33][34][35][36][37].…”

Section: Methodsmentioning

confidence: 99%

Development of Pyramidal Microwave Absorber Using Sugar Cane Bagasse (Scb)

Zahid¹,

Malek²,

Nornikman³

et al. 2013

PIER

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Abstract-The need to find ways to effectively utilize the large quantities of agricultural waste that are produced is indicative of the huge potential associated with producing an alternative pyramidal microwave absorber for anechoic chamber-testing applications. We propose the development of a pyramidal microwave absorber that can use sugar cane bagasse (SCB), a byproduct from the production and processing of sugar cane, as the absorbent. In this paper, we report the results of our use of dielectric probe measurement to determine the dielectric constant and loss tangent of SCB. These values were used to model and simulate an SCB pyramidal microwave absorber in Computer Simulation Technology's (CST's) Microwave Studio. This absorber was operated in the microwave frequency range between 0.1 GHz and 20.0 GHz.

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Composites Based on Rice Husk Ash/Polyester for Use as Microwave Absorber

Lee

Malek

Cheng

et al. 2015

Lecture Notes in Electrical Engineering

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This paper is to study the dielectric properties and microwave absorption of rice husk ash/polyester (RHAP) composites. The RHAP composites prepared with different weight ratio (40-80 wt. %) of rice husk ash (RHA) loading into polyester was fabricated. A rectangular waveguide transmission line method was used to measure the dielectric properties of the RHAP composites. The RHAP samples were designed and simulated with different thickness and percentage of RHA loading by using Computer Simulation Technology Microwave Studio (CST-MWS) software. The materials, their dielectrics properties measurement and microwave absorption result over 12.4-18 GHz (Ku-Band) frequency range are discussed. The dielectric properties of composites increase with increasing loading the RA wt%. The RHAP sample with different thickness was investigated in Ku-Band. The microwave absorption was up to 99.84 %, using 80 % loading of RHA with thickness 15 mm at 13.81 GHz, and showing the RHAP composites is applicable as microwave absorber.

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Setup and Results of Pyramidal Microwave Absorbers Using Rice Husks

Cited by 40 publications

References 27 publications

A Study of the Emc Performance of a Graded-Impedance, Microwave, Rice-Husk Absorber

A Study of the Emc Performance of a Graded-Impedance, Microwave, Rice-Husk Absorber

Development of Pyramidal Microwave Absorber Using Sugar Cane Bagasse (Scb)

Composites Based on Rice Husk Ash/Polyester for Use as Microwave Absorber

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