The phase difference method (PDM) is presented for the direction of arrival (DOA) estimation of the narrowband source. It estimates the DOA by measuring the reciprocal of the phase range of the sensor output spectra a...The phase difference method (PDM) is presented for the direction of arrival (DOA) estimation of the narrowband source. It estimates the DOA by measuring the reciprocal of the phase range of the sensor output spectra at the interest frequency bin. The peak width and variance of the PDM are presented. The PDM can distinguish closely spaced sources with different and unknown center frequencies as long as they are separated with at least one frequency bin. The simulation results show that the PDM has a better resolution than that of the conventional beamforming.展开更多
Under the circumstance of optical axis being in the incident plane,the evanescent wave of total reflection is studied when an extraordinary beam is incident from an isotropic medium upon a uniaxial crystal by using th...Under the circumstance of optical axis being in the incident plane,the evanescent wave of total reflection is studied when an extraordinary beam is incident from an isotropic medium upon a uniaxial crystal by using the general characteristics of uniaxial crystal and electromagnetic field.This paper presents the propagation directions of equiphase plane and the images of evanescent wave,and reveals that the equiamplitude plane and the equiphase plane are not in quadrature any more,and the phase difference between longitudinal wave and transversal wave does not equal π/2,either.But the reflectivity is still kept at 100.展开更多
基金the National Science Foundation under Grant No. 60672136the the Doctorate Foundation of Northwestern Polytechnical University under Grant No.CX200803
文摘The phase difference method (PDM) is presented for the direction of arrival (DOA) estimation of the narrowband source. It estimates the DOA by measuring the reciprocal of the phase range of the sensor output spectra at the interest frequency bin. The peak width and variance of the PDM are presented. The PDM can distinguish closely spaced sources with different and unknown center frequencies as long as they are separated with at least one frequency bin. The simulation results show that the PDM has a better resolution than that of the conventional beamforming.
文摘Under the circumstance of optical axis being in the incident plane,the evanescent wave of total reflection is studied when an extraordinary beam is incident from an isotropic medium upon a uniaxial crystal by using the general characteristics of uniaxial crystal and electromagnetic field.This paper presents the propagation directions of equiphase plane and the images of evanescent wave,and reveals that the equiamplitude plane and the equiphase plane are not in quadrature any more,and the phase difference between longitudinal wave and transversal wave does not equal π/2,either.But the reflectivity is still kept at 100.
