Ahmad Safaai-Jazi

Learn More
Ultra wideband (UWB) wireless communication has been the subject of extensive research in recent years due to its potential applications and unique capabilities. However, many important aspects of UWB-based communication systems have not yet been thoroughly investigated. In particular, indoor channel modeling, interference effects, and the role of antennas(More)
(Abstract) Pressure measurements are required in various industrial applications, including extremely harsh environments such as turbine engines, power plants and material-processing systems. Conventional sensors are often difficult to apply due to the high temperatures, highly corrosive agents or electromagnetic interference (EMI) noise that may be present(More)
Optical sensors have been investigated and widely deployed in industrial and scientific measurement and control processes, mainly due to their accuracy, high sensitivity and immunity to electromagnetic interference and other unique characteristics. They are especially suited for harsh environments applications, where no commercial electrical sensors are(More)
Fiber Raman amplification using the transmission line is a promising technology to increase the repeater distance as well as the capacity of the communication systems. Because of the growing importance of fiber Raman amplification, it is desired to predict the magnitude and shape of the Raman gain spectrum from the doping level and refractive index profiles(More)
In an extensive outdoor propagation study, low antenna heights of 1.7 m are used at both the transmitter and the receiver to measure over 3500 wideband power-delay prooles PDPs of the channel for a peer-to-peer communications system. Rural and urban areas are studied in 22 different transmitter-receiver links. The results are used to characterize the(More)
A generalized analysis of multiple-clad cylindrical dielectric structures with step-index profiles is presented. This analysis yields unified expressions for fields, dispersion equation and cutoff conditions for weakly guiding optical fibers with step-index but otherwise arbitrary profiles. The formulation focuses on triple-clad fibers, but can accommodate(More)
—The application of a recently introduced microwave imaging technique based on the Huygens principle (HP), has been extended to multilayered objects with inclusions in this paper. The methodology of HP permits the capture of contrast such that different material properties within the region of interest can be discriminated in the final image, and its(More)