Modeling of RF Absorber for Application in the Design of Anechoic Chamber

Chung, Boon-Kuan; Chuah, H. T.

doi:10.2528/pier03052601

Cited by 69 publications

(28 citation statements)

References 4 publications

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“…A proper model of RF microwave absorber must be developed based on various parameters such as the absorber reflection loss, the magnitude and phase, for various angles of incidence, and for parallel and perpendicular polarizations [4,12,20,21]. The reflection loss, R, can be expressed as the absorbing performance of the material and is a function of the complex permittivity, permeability of the material, and the frequency of the electromagnetic wave [22].…”

Section: Introductionmentioning

confidence: 99%

Parametric Study of Pyramidal Microwave Absorber Using Rice Husk

Nornikman¹,

Malek²,

Soh³

et al. 2010

PIER

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Section: Introductionmentioning

confidence: 99%

Parametric Study of Pyramidal Microwave Absorber Using Rice Husk

Nornikman¹,

Malek²,

Soh³

et al. 2010

PIER

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“…Based on the reflectivity information from the manufacturer's data sheet, the absorber can be modeled as plane-boundary lossy dielectric with infinite thickness having an effective dielectric constant ε ef f = 1.006 and effective conductivity σ ef f = 0.003 S/m [15]. An asymmetricalshaped anechoic chamber has been designed and constructed.…”

Section: Modeling and Measurement Resultsmentioning

confidence: 99%

Modeling of Anechoic Chamber Using a Beam-Tracing Technique

Chung¹,

Teh²,

Chuah³

2004

PIER

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Abstract-Building an anechoic chamber involves a substantial investment both financially and in physical space. Hence, there is much interest in trying to reduce the required investment while still maintaining adequate performance. The performance of an anechoic chamber depends on the type, size, and array configuration of the absorber elements as well as the geometry of the screened room on which the inner surfaces are covered with RF absorbers. If the room geometry is designed such that an electromagnetic ray from the transmitter will only reach the receiver antenna after a few reflections, the wave energy may be sufficiently damped after a few bounces off the absorbing walls and ceiling. Hence, lower cost RF absorbers can be used to make the anechoic chamber design more economical. In this paper, a variant of beam-tracing technique is used for modeling of anechoic chamber to study the normalized site attenuation (NSA) performance of the anechoic chamber. This allows the chamber performance to be predicted prior to the actual construction. The major advantage of beam-tracing over ray tracing is the path loss information at multiple receiver locations can be determined simultaneously as opposed to running a ray tracing simulation for each receiver location one at a time. As a result, the computing time is greatly reduced. This feature is particularly useful in calculating the field strength at different heights of the receiving antenna in EMC site calibration procedure. The efficient modeling tool has given rise to the successful design and construction of an asymmetrical shape anechoic chamber that supports various measurement needs including EMC tests at

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“…With the growth of modern electronics and telecommunication products in medical, commercial, and military command and control systems, demand for electromagnetic compatibility (EMC) chambers with diversity in size and shape has increased significantly. Electronic products must meet both emission and immunity requirements of EMC regulations before they can be advertised in the market [4]. Different regulatory authorities and commissions regulate the EMC issues worldwide.…”

Section: Introductionmentioning

confidence: 99%

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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Modeling of RF Absorber for Application in the Design of Anechoic Chamber

Cited by 69 publications

References 4 publications

Parametric Study of Pyramidal Microwave Absorber Using Rice Husk

Parametric Study of Pyramidal Microwave Absorber Using Rice Husk

Modeling of Anechoic Chamber Using a Beam-Tracing Technique

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

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