| 1. |
- Fhager, Andreas, 1976, et al.
(författare)
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Clinical Diagnostics and Treatment with Electromagnetic Fields
- 2010
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Ingår i: 4th European Conference on Antennas and Propagation, EuCAP 2010; Barcelona; Spain; 12 April 2010 through 16 April 2010. - 9788476534724 ; , s. C15P2-1
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Konferensbidrag (refereegranskat)abstract
- There is a need for novel diagnostic and treatment systems to overcome the limitations with todays modalities. Microwave and THz based system has the potential to become both sensitive and specific in several applications. In this paper we discuss several applications that are currently being developed at the Chalmers University of Technology.
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| 2. |
- Fhager, Andreas, 1976, et al.
(författare)
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Progress in clinical diagnostics and treatment with electromagnetic fields
- 2011
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Ingår i: Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011. Rome, 11-15 April 2011. - 9788882020743 ; , s. 1936-1937
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Konferensbidrag (refereegranskat)abstract
- There is a need for novel diagnostic and treatment systems to overcome the limitations with todays modalities. Microwave and THz based system has the potential to become both sensitive and specific in several applications. In this paper we discuss several applications that are currently being developed at the Chalmers University of Technology.
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| 3. |
- Nilsson, Emil, et al.
(författare)
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A new CMOS radio for low power RFID applications
- 2010
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Ingår i: Proceedings of 2010 IEEE International Conference on RFID-Technology and Applications : June 17-19, 2010 : Dong Fang Hotel, Guangzhou, China.. - Piscataway, N.J. : IEEE Press. - 9781424467006 ; , s. 106-111
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Konferensbidrag (refereegranskat)abstract
- A novel radio receiver circuit, functioning as a tuned active, detecting antenna, is described. The receiver is suggested to be part of a new radio system with the potential of competing with the range capability of active RFID-tags and, through its low power and long lifetime, with passive RFID-tags. The circuit is outlined and the functionality is verified by simulations and measurements.A 24 MHz discrete prototype showed better than -70 dBm sensitivity and 5 kHz bandwidth, with a power consumption of 102 μW. Simulations of a monolithic implementation were performed at 2.5 GHz. The detector is modeled by using 180 nm CMOS transistors. In simulations the power consumption for the detector is below 125 μW at a sensitivity of -83 dBm and a bandwidth of 9 MHz.Our conclusion is that this novel simple circuit architecture is well suited for monolithic implementation of a low power transceiver.
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| 4. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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Accuracy Evaluation of Ultrawideband Time Domain Systems for Microwave Imaging
- 2011
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 59:11, s. 4279-4285
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Tidskriftsartikel (refereegranskat)abstract
- We perform a theoretical analysis of the measurement accuracy of ultrawideband time domain systems. The theory is tested on a specific ultrawideband system and the analytical estimates of measurement uncertainty are in good agreements with those obtained by means of simulations. The influence of the antennas and propagation effects on the measurement accuracy of time domain near field microwave imaging systems is discussed. As an interesting application, the required measurement accuracy for a breast cancer detection system is estimated by studying the effect of noise on the image reconstructions. The results suggest that the effects of measurement errors on the reconstructed images are small when the amplitude uncertainty and phase uncertainty of measured data are less than 1.5 dB and 15 degrees, respectively.
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| 5. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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Accuracy investigation of an ultra-wideband time domain microwave imaging system
- 2011
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Ingår i: Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011. Rome, 11-15 April 2011. - 9788882020743 ; , s. 1928-1932
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Konferensbidrag (refereegranskat)abstract
- We investigate the measurement accuracy of an ultra-wideband time domain microwave tomography system. A phantom is imaged by means of the system and the reconstructed images are compared to those obtained with an ultra-wideband frequency domain system. The results suggest that the permittivity reconstructions obtained by means of the time domain and the frequency domain systems are very similar to each other, but the conductivity profile reconstructed from time domain measurements presents worse quality than that obtained from frequency domain measurements.
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| 6. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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An ultrawideband microwave medical diagnostic system: Design considerations and system performance
- 2012
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Ingår i: Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012. Prague, 26-30 March 2012. - 9781457709180 ; , s. 3664-3668
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Konferensbidrag (refereegranskat)abstract
- We discuss several issues in the design of an ultra-wideband microwave system dedicated to medical diagnostics. Based on the discussion, a FPGA-based time domain microwave diagnostic system is proposed. The noise sources of the system are identified and the system noise performance is analyzed. As an example, a 2-D antenna system is considered and the measurement signal to noise ratios are evaluated.
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| 7. |
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| 8. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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Design and Performance Evaluation of a Time Domain Microwave Imaging System
- 2013
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Ingår i: International Journal of Microwave Science and Technology. - : Hindawi Limited. - 1687-5826 .- 1687-5834. ; 2013, s. Art. no. 735692-
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Tidskriftsartikel (refereegranskat)abstract
- We design a time domain microwave system dedicated to medical imaging. The measurement accuracy of the system, that is, signal-to-noise ratio, due to voltage noise and timing noise, is evaluated. Particularly, the effect of coupling media on the measurement accuracy is investigated both numerically and experimentally. The results suggest that the use of suitable coupling media betters the measurement accuracy in the frequency range of interest. A signal-to-noise ratio higher than 30 dB is achievable in the range of 500 MHz to 3 GHz when the effective sampling rate is 50 Gsa/s. It is also indicated that the effect of the timing jitter on the strongest received signal is comparable to that of the voltage noise.
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| 9. |
- Zeng, Xuezhi, 1980, et al.
(författare)
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Experimental Investigation of the Accuracy of an Ultrawideband Time-Domain Microwave-Tomographic System
- 2011
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 1557-9662 .- 0018-9456. ; 60:12, s. 3939-3949
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Tidskriftsartikel (refereegranskat)abstract
- The measurement accuracy of an ultrawideband (UWB) time-domain microwave-tomographic system is investigated. In order to make an assessment of the random variation of the measurements, the measurement repeatability of the system is evaluated by comparison with an UWB frequency-domain system. A phantom is imaged with the time-domain microwave-tomographic system, and the reconstructed images are compared with those obtained by using the frequency-domain system. The results suggest that with the averaging tens of measurements, the time-domain system can achieve the same level of measurement repeatability as that of the frequency-domain system in the interesting frequency range of microwave tomography. The imaging results, however, indicate that the phantom reconstruction does not require such high measurement accuracy. The permittivity profile of the phantom reconstructed from the nonaveraging time-domain measurements is very similar with that obtained by means of the frequency-domain system.
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