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1

SP8T switch design using cascaded SPDT switches for monostatic microwave imaging system in medical application

Shairi Noor Azwan, Sanusi Nursyahirah Mohd, Othman Adib, Zakaria Zahriladha, Ibrahim Imran Mohd, Zobilah Abdullah Mohammed Saghir, Joret Ariffuddin

Przegląd Elektrotechniczny

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2022

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R. 98, nr 7

131--136

EN

This paper proposes a single pole eight throw switch (SP8T) using cascaded single pole double throw (SPDT) switches. The switch design is to control eight antenna array in the monostatic microwave imaging system for medical application. A mathematical modeling was done for a simple series-shunt SPDT switch for the analysis of insertion loss, return loss and isolation. Then, a proper selection of SPDT switch topologies was carried out in a simulation software in order to get ultra wideband (UWB) performance of the SP8T switch design. As a result, the proposed SP8T switch produced 9.3 GHz of isolation bandwidth that can be used for a Gaussian pulse up to 9.3 GHz bandwidth (from 1.7 GHz to 11 GHz frequency spectrum).

PL

W niniejszym artykule zaproponowano jednobiegunowy przełącznik ośmiorurowy (SP8T) wykorzystujący kaskadowe jednobiegunowe przełączniki dwustanowe (SPDT). Konstrukcja przełącznika służy do sterowania układem ośmiu anten w monostatycznym mikrofalowym systemie obrazowania do zastosowań medycznych. Przeprowadzono modelowanie matematyczne prostego przełącznika SPDT z bocznikiem szeregowym do analizy tłumienia wtrąceniowego, tłumienia odbiciowego i izolacji. Następnie dokonano właściwego wyboru topologii przełącznika SPDT w oprogramowaniu symulacyjnym, aby uzyskać wydajność ultraszerokopasmową (UWB) projektu przełącznika SP8T. W rezultacie proponowany przełącznik SP8T wytworzył pasmo izolacji 9,3 GHz, które można wykorzystać dla impulsu Gaussa o szerokości do 9,3 GHz (widmo częstotliwości od 1,7 GHz do 11 GHz).

2

A 3D directive microwave antenna for biomedical imaging application

Ullah M. A., Alam T., Islam M. T.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 3

355--360

EN

A directive three dimensional antenna, using folded radiating structure has been presented for the application of microwave imaging in clinical diagnosis. Two reflector walls have been introduced to achieve higher gain and directive radiation pattern along with the folding technique. The shorting wall technique is utilized to reduce the overall antenna size and to get resonance at a lower frequency. The proposed antenna obtained operating band at 1.67 GHz to 1.74 GHz. The dimension of the 3D radiating structure is 40£25£10.5 mm3. The antenna has an average realized gain of 5.2 dBi. Owing to the unidirectional radiation pattern, high gain and operating bandwidth within lower microwave frequency, the proposed antenna has potential to be used in microwave imaging for biomedical diagnosis. Also, the antenna has been utilized to compute an imaging phenomenon to detect abnormality in human head and result is presented. The design and simulation process are performed in the CST Microwave Studio software. The antenna is fabricated from 0.2 mm thick copper sheets. The results of the fabricated antenna are measured using PNA Network Analyzer (N5227A) and Satimo Star Lab.

3

Variational Bayesian inversion for microwave breast imaging

Gharsalli L., Ayasso H., Duchêne B., Mohammad-Djafari A.

Computer Assisted Methods in Engineering and Science

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2014

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Vol. 21, no. 3-4

199--210

EN

Microwave imaging is considered as a nonlinear inverse scattering problem and tackled in a Bayesian estimation framework. The object under test (a breast affected by a tumor) is assumed to be composed of compact regions made of a restricted number of different homogeneous materials. This a priori knowledge is defined by a Gauss-Markov-Potts distribution. First, we express the joint posterior of all the unknowns; then, we present in detail the variational Bayesian approximation used to compute the estimators and reconstruct both permittivity and conductivity maps. This approximation consists of the best separable probability law that approximates the true posterior distribution in the Kullback-Leibler sense. This leads to an implicit parametric optimization scheme which is solved iteratively. Some preliminary results, obtained by applying the proposed method to synthetic data, are presented and compared with those obtained by means of the classical contrast source inversion method.

4

Improvement of the Microwave Imaging System by Deconvolution of the Antenna Pulse Response

Bury M., Yashchyshyn Y., Modelski J.

International Journal of Electronics and Telecommunications

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2010

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Vol. 56, No. 3

209-214

EN

In the paper a microwave imaging system and its algorithm of image reconstruction from the raw measurement data were briefly introduced. Authors observed that pulse responses of the antennas used in the system have similar duration to the measurement pulse and therefore also contribute to the limits of system resolution. Paper presents a simple method that improves the system performance by additional deconvolution of the antenna pulse responses. Method was verified experimentally.

5

Numerical models of human breast

Michałowska-Samonek J., Miaskowski A., Wac-Włodarczyk A.

Przegląd Elektrotechniczny

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2009

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R. 85, nr 12

125-127

EN

The aim of the paper is to introduce the online repository of numerical breast models, obtained using MRI. These free available models allow to better illustrate changes setting in breast through obtained fairly accurate characteristics of tissues i.e. the models assemble the structural heterogeneity of normal breast tissues and the realistic dispersive dielectric properties in frequency range 0.5-20 GHz based on Debye’s model.

PL

Celem artykułu jest prezentacja darmowego repozytorium naturalistycznych, numerycznych modeli gruczołu piersiowego i jego krótkie omówienie. Modele te pozwalają zobrazować heterogeniczną budowę gruczołu piersiowego, a także odwzorować właściwości dyspersyjne jego tkanek w zakresie częstotliwości 0.5-10 GHz w oparciu o parametryczny model Debye’a.

6

Zastosowanie ultrakrótkich impulsów w mikrofalowym systemie obrazującym

Bury M., Kozłowski S., Jaszczyszyn E.

Elektronika : konstrukcje, technologie, zastosowania

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2008

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Vol. 49, nr 2

22-25

PL

Zaprezentowano model laboratoryjny mikrofalowego systemu obrazującego. System ten pozwala na uzyskanie przekroju poprzecznego obiektu umieszczonego na stole obrotowym i oświetlanego pod różnymi kątami ultrakrótkimi impulsami mikrofalowymi. Omówiono uproszczony model matematyczny systemu, wyniki symulacji komputerowych oraz wyniki pomiarów.

EN

The paper concerns a laboratory model of microwave imaging system. It allows obtaining the cross-section of the object under test located on a revolving platform and excited with ultra short microwave pulses. The cross-section is calculated on a base of raw measurement data matrix constituted by the received signals, reflected from the object under test for subsequent angle locations. Paper presents mathematical model of the system, the results of computer simulations as well as measurement results.