Publications

M. Haridim, T. Haguel, R. Zemach, O. Hilly,
Heterogeneous SAR head distribution model for correlation demonstration to ears canal acoustic neuroma pathology, IEEE MTT-S Int'l. Conf. on Numerical, Electromagnetic and Multiphysics Modeling and Optimization for RF, Microwave, and Terahertz Applications (NEMO 2015), Ottawa, Canada, 11-14 August 2015
http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7415097

Description: Abundant applications of wireless devices raise growing health concerns among public users. Efforts to display definite relation between human exposure to wireless RF radiation and health diseases' appearance are not yet conclusive. Causal relationship and defined correlations are yet to be demonstrated. Case study of Acoustic Neuroma ear's pathology is estimated with respect to SAR distribution at typical physical appearances. In this paper, homogeneous and heterogeneous models are employed for SAR evaluation at Acoustic Neuroma region, yielding values of 1.4 Watt/Kg and 0.4 Watt/Kg, respectively. Though values are below known limits, heat absorption could initiate some of this disease eruption.

B. Dubovski, M. Haridim,
A high efficiency WPT system using Helix antennas, Progress in Electromagnetics Research Symp. (PIERS 2015), Prague, Czech Republic, 6-9 July 2015

B. Levin, M. Haridim,
Transpa rent antenna with metal triangle, IEEE Trans. on Antennas and Propagation, March 2015

P. Malits, M. Haridim, S. Chulski,
TEM wave propagation in a microstrip line on a substrate of circular segment cross section, Zeitschrift fűr Angewandte Mathematik und Physik ZAMP 66, 2015 (11 pages) [published online 15 October 2015]
https://alephproject.hit.ac.il/articles/ENG2/39722.pdf

Description: TEM mode wave propagation in a microstrip transmission line on a dielectric substrate of circular segment cross section is of concern. A suggested design of a microstrip is convenient for manufacturing and allows to miniaturize microstrips since there is no lateral fringing effect of the substrate in the transmitted fundamental TEM mode. By using the bipolar orthogonal coordinates, the plane potential problem is reformulated in the form of trigonometric dual integral equations. The discontinuous integrals containing Legendre functions of complex degree and the Abel integral equation are employed to reduce the dual equations to a Fredholm equation of the second kind. The structure of the Fredholm integral equation allows to obtain a simple approximate solution. Basing on this solution, rigorous approximate formulas for the characteristic impedance are derived. The characteristic impedance of a microstrip transmission line on a silicon substrate is computed and plotted as an example

S. Sayfan-Alman, V. Vulfin, M. Haridim,
Designing high-speed signal distribution for multi-drop connection using simulations, 28th Conv. of Electrical and Electronics Engineers in Israel – Electricity 2014, Eilat, Israel, 3-5 December 2014
https://alephproject.hit.ac.il/articles/ENG2/39675.pdf

Description: Multi point distribution is used in many applications. Connection of multiple taps along the signal transmission line leads to impedance changes, and as a result the signalintegrity may be degraded. This makes the design more challenging, especially in high speed circuits. Bus design layout that achieves both impedance matching and uniform power distribution for a multi-drop bus has been recently proposed. These designs are mostly based on resistor impedance matching for each branch. In most designs the signal's spectrum is not taken into account when designing multidrop interconnects, and hence the input impedance may not be optimal for the working frequencies. In this paper, we present a scheme that is based on changing the line impedance of each segment of the bus, hence removing the need to add resistors in the layout. We also propose a design method to achieve constant impedance along the transmission line, using information derived from the signal spectrum. The simulation results of circuit boards design demonstrate good agreement with the theoretical results, and show reliable performance at high bit rates

M. Haridim, B. Levin,
Antennas placed along the sides of a pyramid, IEEE Trans. on Electromagnetic Compatibility June 2014 　

M. Haridim, B. Levin, S. Revich, S. Chulski, R. Sauleau, R. Zemach,
Distribution of energy absorption in an inhomogeneous head model at 900 MHz, IEEE Electromagnetic Compatibility Magazine, 3(4), 2014 (43-48)

 

Description: Aninhomogeneousmodelof the humanhead, which consists of a number of tissues, is compared with a homogeneousmodel, commonly used for the evaluation of electromagnetic (EM) field inside theheadin the900-MHzfrequency band. For both models, the level of exposure in theheadis evaluated by means of numerical simulation of the SpecificAbsorptionRate (SAR) in the wholeheadand in separated areas. It is shown that the homogeneous andinhomogeneousmodels lead approximately to the same total SAR, but the magnitudes of the maximal point SAR and the local SAR in theinhomogeneousmodelare significantly higher than in the homogeneous one.

B. Levin, M. Haridim, M. Bank,
Cellular phone antenna with a small irradiation of human head, IEEE Antennas and Propagation Magazine, 55(4), 2013 (113-127)

 

Description: A compensation method for reducing the irradiation of the head of a cellular phone user without degradation of the far field is analyzed. This method uses two radiators that are located in the near region of each other, and create a weak field area in this region. The impacts of the mutual coupling between closely located radiators on the input impedance, current distribution, and fields of the radiators are studied. It is shown that the structure of two closely spaced monopoles is equivalent to the superposition of two basic structures: a two-wire open-ended line, and a single monopole. The shape and dimensions of the dark spots and the irradiation-reduction factor are determined. To facilitate the field calculations in the near zone of the antennas, a method based on replacing a piecewise-homogenous medium by an equivalent homogenous medium is used. The calculations and the experimental results in the presence of the head qualitatively agreed.

M. Haridim, B. Levin, S. Revich, S. Chulski,
Effect of head heterogeneity on a cellular phone field, 2013 IEEE Int'l. Symp. on Electromagnetic Compatibility (EMC 2013) "Winds of Change“, Denver, Colorado, USA, 5-9 August 2013 (163-166)
https://alephproject.hit.ac.il/articles/ENG1/38787.pdf

Description: The impact of the heterogeneous nature of the human head on SAR magnitude is investigated. Two models of the human head, heterogeneous and homogeneous, are considered. Numerical electromagnetic simulations of the head irradiation for both models are performed. The magnitudes of total, local and point SAR and also the SAR distribution in different areas of the head are calculated. It is shown that the magnitudes of point and local SAR in the heterogeneous model are significantly higher than in the homogeneous one, especially in areas susceptible to cancer