Jian-Gang Zhu

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This paper presents the time reversal adaptive interferer can-celler (TRAIC), a novel algorithm that uses time reversal techniques to cancel the presence of interferers. TRAIC is developed for broadband signals and a single emitting antenna. Experimental tests in the electromagnetic domain show the viability and the power of TRAIC.
Introduction A cluttered environment with highly scattering objects significantly enhances the difficulty for detecting targets using electromagnetic wave. In this paper, we present a novel time reversal method that nullifies the scattering objects to allow automatic focusing of the propagated electromagnetic wave on a target that is to be detected. Time(More)
FePt– MgO two phase thin films have been obtained by an alternating sputtering method at elevated temperatures. It is found that the L1 0 FePt grains grow in a columnar manner through the thickness of the film and possess a ͑001͒ perpendicular texture promoted by the ͑200͒-textured crystalline MgO underlayer. The amorphous MgO in the two phase mixture forms(More)
− Super-resolution focusing and nulling experiments are described based on multipath-enhanced time-reversal techniques. Using these techniques, two independent 2.45 GHz signals focused at locations separated by 5 cm at a distance of 6.7 m are successfully demodulated.
The order parameter of FePt thin films plays an essential role in determining such diverse materials properties as magneto-crystalline anisotropy, magnetic coercivity and magnetic recording density. Typically, the order parameter for a bulk material is obtained by measuring the X-ray integrated intensity ratio of a super lattice peak to a fundamental peak(More)
—Grain-to-grain anisotropy field variation has become one of the main causes of medium noise, especially in perpendicular thin film media. In this paper, we present an electron microscopy investigation and theoretical analysis on the grain-to-grain anisotropy field variation in various types of thin film recording media. In alloyed film media, the intrinsic(More)
In this paper we derive the generalized likelihood ratio test (GLRT) for time reversal detection. We consider a multi-static array configuration with two antenna arrays, one for transmitting and one for receiving. We examine the time reversal GLRT performance with experimental measurements in the electromagnetic domain in a highly cluttered laboratory(More)
In this work, we present an experimental technique for obtaining highly ordered L1 0 FePt-oxide thin film media at moderate depo-sition temperatures. In most previous studies, a FePt-Oxide layer is directly deposited on a (001) textured MgO layer. By introducing a buffer layer in between the FePt-oxide layer and the MgO underlayer, we are able to(More)