Microwave Absorption and EMI Shielding Behavior of Nanocomposites Based on Intrinsically Conducting Polymers, Graphene and Carbon NanotubesParveen Saini1 and Manju Arora1[1] National Physical Laboratory, New Delhi, , India1.
GO functionalized amino group polymerized alongwith aniline monomer moiety shows excellent shielding behavior and more studies are being carried out.
Beside, these composites also give (Figure 2) shielding effectiveness of -23.3 dB (>99% attenuation). Recently, an initiative has been taken towards the designing and development of efficient EMI shielding and supercapacitor electrode materials based on graphene and its nanocomposites. Frequency and dopant concentration dependence of total shielding effectiveness (SET) value of samples prepared by doping of emeraldine base (EB) with different concentrations of acrylic acid (AA) viz.
Thickness dependence of total shielding efficiency (SET) of various ‘‘crosslinked’’ polyaniline (XPANI-ES) samples.


The first section of this chapter gives a brief overview of fundamentals of EMI shielding & microwave absorption, theoretical aspects of shielding, governing equations, various techniques for measurement of shielding effectiveness and different strategies for controlling EMI.
Therefore, some shielding mechanism must be provided to ensure undisturbed functioning of devices even in the presence of external electromagnetic (EM) noises. The designing a EMI shielding with a certain level of attenuation, meeting a set of physical criteria, maintaining economics and regulating the involved shielding mechanism is not a straight forward task and involves complex interplay of intrinsic properties (?, and ?) of shield material and logical selection of extrinsic parameters.
Therefore, to touch the theoretically predicted shielding performance of a materials and to satisfy stringent design criteria, elementary knowledge of shielding theory, set of governing theoretical equations, important design parameters and relevant measurement technique becomes a prime prerequisite. Shielding definitions and phenomenonEMI shield is essentially a barrier to regulate the transmission of the electromagnetic EM wave across its bulk. Shielding is the process by which a certain level of attenuation is extended using a strategically designed EM shield.


Theoretical shielding effectivenessBefore starting the shielding analysis, it is necessary to understand the various electromagnetic terminologies (Ott, 2009). Shielding theory This section presents the shielding basics based on the transmission line theory (Schelkunoff, 1943) and the plane wave shielding theory (Schulz et al,1988).



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Comments

  1. 19.02.2015 at 17:39:40


    Even so, it electromagnetic shielding effectiveness is very critical can you recommend, if they operate and speak with your neighbors.

    Author: GERARD
  2. 19.02.2015 at 23:25:47


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    Author: ismayil