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
The effect of the microstrip bend on the propagation characteristics of a microstrip line was investigated based on the Finite-Difference Time-Domain(FDTD)method.The dispersive characteristics of a microstrip line wit...The effect of the microstrip bend on the propagation characteristics of a microstrip line was investigated based on the Finite-Difference Time-Domain(FDTD)method.The dispersive characteristics of a microstrip line with a bend are quite different from that of a uniform straight microstrip line.The effect of bend discontinuity on propagation constants deceases exponentially with the distance form the corner of the bend.This can be explained by the fact that the higher order modes excited by the bend discontinuities have intrinsic properties of exponentially decay with the distance from the bend discontinuities.This effect can be negligible(less than five percent)when the distance is beyond ten times of conductor strip width.The S parameters and propagation constants comparison between unmitered and mitered bends are also presented.The proposed method which takes advantage of the FDTD algorithm and the Root Mean Square Deviation(RMSD)analysis is also an effective way for analyzing the dispersion characteristics of other planar transmission lines.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.
基金supported by basic research item of National Key Lab of Electronic Measurement Technology and National Natural Science Foundation of China(No.60876028,60633060)
文摘The effect of the microstrip bend on the propagation characteristics of a microstrip line was investigated based on the Finite-Difference Time-Domain(FDTD)method.The dispersive characteristics of a microstrip line with a bend are quite different from that of a uniform straight microstrip line.The effect of bend discontinuity on propagation constants deceases exponentially with the distance form the corner of the bend.This can be explained by the fact that the higher order modes excited by the bend discontinuities have intrinsic properties of exponentially decay with the distance from the bend discontinuities.This effect can be negligible(less than five percent)when the distance is beyond ten times of conductor strip width.The S parameters and propagation constants comparison between unmitered and mitered bends are also presented.The proposed method which takes advantage of the FDTD algorithm and the Root Mean Square Deviation(RMSD)analysis is also an effective way for analyzing the dispersion characteristics of other planar transmission lines.
