Wasi Ur Rehman Khan¹, Muhammad Fawad Khan¹, Muhammad Irfan², Sadiq Ullah¹, Naveed Mufti¹, Usman Ali¹, Rizwan Ullah¹, Fazal Muhammad^3,*, Saifur Rahman², Faisal Althobiani⁴, Mohammed Alshareef⁵, Mohammad E. Gommosani⁶

CMC-Computers, Materials & Continua, Vol.74, No.2, pp. 2517-2530, 2023, DOI:10.32604/cmc.2023.031833

Abstract A compact, reconfigurable antenna supporting multiple wireless services with a minimum number of switches is found lacking in literature and the same became the focus and outcome of this work. It was achieved by designing a Th-Shaped frequency reconfigurable multi-band microstrip planar antenna, based on use of a single switch within the radiating structure of the antenna. Three frequency bands (i.e., 2007–2501 MHz, 3660–3983 MHz and 9341–1046 MHz) can be operated with the switch in the ON switch state. In the OFF state of the switch, the antenna operates within the 2577–3280 MHz and 9379–1033 MHz Bands. The proposed antenna shows an acceptable input impedance… More >

Lin Li, Li Jicheng, Wu Di, Li Ximeng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 39-40, 2011, DOI:10.3970/icces.2011.017.039

Abstract Two kinds of plasma sprayed Cr2O3 coatings are tested with electro-mechanical impedance (EMI) method. The influence of frequency band on the testing sensitivity of EMI method is investigated in kHz and MHz frequency ranges. The frequency shifts and root mean square deviation (RMSD) of the PZT electric impedance signatures are used as evaluation indicator. The variation of EMI sensitivity is investigated on 8 frequency bands with high mode density in the frequency ranges of 0.1-600 kHz and 1-10 MHz. The results show that in the low frequency range, the frequency shifts increase and the RMSD values first increase and then… More >

B.Y. Tian¹, B. Tie¹, D. Aubry¹, X.Y. Su²

CMES-Computer Modeling in Engineering & Sciences, Vol.76, No.3&4, pp. 217-234, 2011, DOI:10.3970/cmes.2011.076.217

Abstract The present work is devoted to a theoretical analysis and numerical modeling of elastic wave propagation firstly in a one-dimensional periodic elastic rod structure and then in two-dimensional periodic elastic beam structures by using Bloch wave theorem. The dispersion relation between Bloch wave vectors and eigen frequencies is obtained and its dependency upon the micro-structural characteristics of the periodic cellular structure is analyzed. Thanks to the Bloch wave transforms, only the primitive cell is considered theoretically or numerically and the phenomena of frequency band-gaps and the diffracted waves caused by the periodic cells are modeled and analyzed. More >