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The debated question of the superluminal speed of information remains open to different interpretations in spite of recent, apparently conclusive, contributions. A different point of view is here considered, which is based on experimental results of microwave propagation experiments, in far-field conditions. They support the hypothesis of the existence of fast waves of the Zenneck type. (c) 2006 American Institute of Physics

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which has the merit of particularly narrow band selectivity. Only the fundamental resonance is highly selected to the feeding I/O ports, which can be demonstrated by the typical stopband simulated electric current density (i.e., 13.3 GHz) of the structure shown in Figure 5. It can be seen that the closed electronic and magnetic coupling paths in the tight coupled DGS TSCFs and microstrip T-stubs lead to low radiation and free spurious. Besides, from the transmission and reflection characteristics of the structure depicted in Figure 4, it demonstrates a low radiation stopband with good spurious suppression in the wide frequency range from the first spurious P p2 up to 20 GHz. Thus, the wide stopband responses are from the intrinsic characteristics of the proposed structure. Based on the investigation above, it can be concluded that the proposed scheme has the following two functions: (1) high selectivity on the fundamental frequency;(2) high rejection on high-order modes or spurious. In addition, it is found that an optimized stopband frequency responses can be obtained, when the ratios of the DGS dimensions (i.e., S 1 : W A : S 2 ) and the T-stub (i.e., W 2 to L 2 /2) are chosen at 3:1:1 and 3:4, respectively.ABSTRACT: By using radar techniques over distances of 16 and 80 m, microwave propagation experiments revealed the presence of anomalous forerunners situated in advanced positions with respect to the main (luminal) peak. These results can be interpreted by a typical diffraction integral, which accounts for the existence of (fast) complex waves, which are usually considered only in the near-field region, but are still surviving beyond this limit.ABSTRACT: An algorithm based on wavelet transform is utilized in detecting and examining the heartbeat signal obtained from a Doppler radar. Time-frequency localization properties of wavelet transform were used to examine the signal and provided detail of swift and slow changes in heart rate over very small periods resulting in better determination of the accuracy of the Doppler radar. Till 1 m, a very accurate and robust performance was observed for the Doppler radar. Even at 2-m heart rate was detectable but not with reasonable accuracy.