Electromagnetic dosimetry for adult and child models within a car: multi-exposure scenarios

2011 ◽  
Vol 3 (6) ◽  
pp. 707-715 ◽  
Author(s):  
Louis-Ray Harris ◽  
Maxim Zhadobov ◽  
Nacer Chahat ◽  
Ronan Sauleau

This paper deals with the numerical dosimetry for adult and children models exposed to CW signals of several wireless communication systems (UMTS, WiMax, and Bluetooth) within a partly shielded environment represented by a realistic car model. More than 20 mono- and multi-source exposure scenarios are considered. Computational results demonstrate that, for all considered exposure scenarios, the specific absorption rate (SAR) is at least 40 times (whole-body average) and 10 times (local SAR) lower than the exposure limits fixed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The whole-body average SAR values for children are found to be typically 1.1–1.3 times higher than those of adults. Under several exposure scenarios, the local SAR in the limbs of children models is 2–3 times higher than corresponding values in adult models. The power density distributions within the car have been also analyzed for one, two, and three simultaneously emitting devices. The results show that the homogeneity of the power density distribution increases with increasing number of simultaneously operating transmitters. These data suggest that the use of several wireless communication devices within a car leads to exposure levels that are several orders of magnitude below international exposure limits, even for the multi-exposure scenarios for both adult and children models.

Author(s):  
Navin M George ◽  
S Merlin Gilbert Raj

This paper presents the design of a fixed antenna of multiple frequency bands. The antenna proposed here will be used in new generation wireless communication devices. This antenna has the ability to radiate multiple bandwidths with a less return loss and improved antenna gain. This model is highly compact and cost effective one. The fixed model is simulated and implemented in hardware and the results are compared.


Author(s):  
A. Suresh Babu ◽  
B. Anand

: A Linear Feedback Shift Register (LFSR) considers a linear function typically an XOR operation of the previous state as an input to the current state. This paper describes in detail the recent Wireless Communication Systems (WCS) and techniques related to LFSR. Cryptographic methods and reconfigurable computing are two different applications used in the proposed shift register with improved speed and decreased power consumption. Comparing with the existing individual applications, the proposed shift register obtained >15 to <=45% of decreased power consumption with 30% of reduced coverage area. Hence this proposed low power high speed LFSR design suits for various low power high speed applications, for example wireless communication. The entire design architecture is simulated and verified in VHDL language. To synthesis a standard cell library of 0.7um CMOS is used. A custom design tool has been developed for measuring the power. From the results, it is obtained that the cryptographic efficiency is improved regarding time and complexity comparing with the existing algorithms. Hence, the proposed LFSR architecture can be used for any wireless applications due to parallel processing, multiple access and cryptographic methods.


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