The Experts below are selected from a list of 50037 Experts worldwide ranked by ideXlab platform

M Kaveh - One of the best experts on this subject based on the ideXlab platform.

  • experimental performance of calibration and Direction Finding algorithms
    International Conference on Acoustics Speech and Signal Processing, 1991
    Co-Authors: J Pierre, M Kaveh
    Abstract:

    In sensor array processing, high-resolution eigenbased Direction-Finding algorithms are known to be sensitive to sensor gain, phase, and mutual coupling errors. In order to approach the algorithms' theoretical Direction-Finding performance in actual arrays, methods are required to measure these errors and compensate for them. The authors develop calibration procedures based on least squares fitting of known measured Direction vectors. After calibration any appropriate Direction-Finding algorithm may be applied. Experimental results from an ultrasonic array testbed demonstrate the performance of the calibration algorithms. A previously proposed autocalibration algorithm is discussed. The algorithm is shown to give nonunique solutions for linear arrays. >

  • Multichannel filtering for wide-band Direction Finding
    IEEE Transactions on Signal Processing, 1991
    Co-Authors: S. Sivanand, M Kaveh
    Abstract:

    A preprocessing stage for wide-band Direction Finding is formulated in the framework of multichannel filtering wherein the filter frequency response matrices are chosen to achieve signal-subspace focusing. Direction Finding based on any narrow-band algorithm is then performed on the filter output. A procedure for specifying a sparse response suitable in nonstationary environments is presented. An approach to filter design that avoids explicit evaluation of the frequency response is proposed. Extensions to beam-space processing are discussed from the standpoint of simple implementation structures. Simulation studies confirm the usefulness of the various focusing multichannel filters. >

  • ICASSP - Experimental performance of calibration and Direction-Finding algorithms
    [Proceedings] ICASSP 91: 1991 International Conference on Acoustics Speech and Signal Processing, 1991
    Co-Authors: J Pierre, M Kaveh
    Abstract:

    In sensor array processing, high-resolution eigenbased Direction-Finding algorithms are known to be sensitive to sensor gain, phase, and mutual coupling errors. In order to approach the algorithms' theoretical Direction-Finding performance in actual arrays, methods are required to measure these errors and compensate for them. The authors develop calibration procedures based on least squares fitting of known measured Direction vectors. After calibration any appropriate Direction-Finding algorithm may be applied. Experimental results from an ultrasonic array testbed demonstrate the performance of the calibration algorithms. A previously proposed autocalibration algorithm is discussed. The algorithm is shown to give nonunique solutions for linear arrays. >

Ronghong Jin - One of the best experts on this subject based on the ideXlab platform.

  • Direction Finding Based on Time-Modulated Array With Multiharmonic Analysis
    IEEE Transactions on Antennas and Propagation, 2020
    Co-Authors: Jingfeng Chen, X. Liang, Junping Geng, Wenzhi Wang, Ronghong Jin
    Abstract:

    Direction Finding with time-modulated array (TMA) has attracted considerable attention recently. In this communication, a multiharmonic analysis for Direction Finding based on TMA is proposed. The linear regression model of the two-element Direction-Finding system is established, and its noise covariance matrix is also analyzed. With the best linear unbiased estimator (BLUE), the high-order harmonic components which were previously ignored in the estimation can be effectively utilized to improve the Direction-Finding accuracy. Compared with conventional single harmonic analysis, simulation results are provided to demonstrate validation of the proposed method for improving the Direction-Finding accuracy. An experimental system based on two-element TMA is constructed and implemented to verify the feasibility of the proposed method.

  • Direction Finding by Time-Modulated Linear Array
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Anjie Cao, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng, Ronghong Jin
    Abstract:

    The Direction Finding method by the time-modulated linear array (TMLA) is analyzed and verified. The Direction of arrival (DOA) can be calculated out by analyzing the spectrum characteristic of the received signal after the time modulation. Its principle is as follows. Because of the periodic modulation, the fundamental and harmonic components are generated in each element simultaneously. After the combiner, the harmonic components’ characteristic of the combined signal is influenced by the DOA. Through analyzing their mathematical relationship, the DOA can be calculated out directly. Compared with the existing Direction Finding methods, the proposed method has two main advantages. One is that only a single RF channel is used, and the other is that its precision can be improved by the time accumulation. The main calculation amount of the proposed method locates in the spectrum estimation for the received signal and the matrix inversion for the harmonic characteristic matrix. Numerical simulations are provided to verify the proposed method, and the related factors influencing on the Direction Finding precision are analyzed. A simple $S$ -band eight-element TMLA is constructed and tested to verify its effectiveness. Finally, some conclusions are drawn, and the further research is sketched out.

  • Direction Finding using time modulated array
    2017 Sixth Asia-Pacific Conference on Antennas and Propagation (APCAP), 2017
    Co-Authors: Ronghong Jin, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng
    Abstract:

    Time modulated array (TMA) has received a great deal of attention recently, owing to their usefulness in numerous applications including radars, sensors and communications. Specifically, with the exploitation of harmonics, generated by periodically modulated switches, TMA is also promising candidates for Direction Finding. In this paper, we take a general review and new perspectives on the Direction Finding using TMA. Some novel ideas, such as Direction Finding with time modulated linear array, Direction Finding of linear frequency modulated signal with TMA, and 2-D Direction Finding with TMA, are presented and discussed.

  • Direction Finding by time modulated linear array
    2017 IEEE International Symposium on Antennas and Propagation & USNC URSI National Radio Science Meeting, 2017
    Co-Authors: X. Liang, Ronghong Jin, Weiren Zhu, Gunping Geng, Anjie Cao, Di Hui
    Abstract:

    A novel Direction Finding method with the time modulated linear array (TMLA) is proposed and verified, by establishing the relationship between the incident angle and the generated harmonic characteristic matrix (HCM). The principle is that the generated HCM because of the periodical modulation varies with the incident Direction of the RF signal. Compared to the existing Direction Finding method, the proposed method has simple structure and low calculation complexity. Numeric simulation is provided to examine its performance and an 8-element S-band TMLA is constructed to verify its effectiveness.

X. Liang - One of the best experts on this subject based on the ideXlab platform.

  • Direction Finding Based on Time-Modulated Array With Multiharmonic Analysis
    IEEE Transactions on Antennas and Propagation, 2020
    Co-Authors: Jingfeng Chen, X. Liang, Junping Geng, Wenzhi Wang, Ronghong Jin
    Abstract:

    Direction Finding with time-modulated array (TMA) has attracted considerable attention recently. In this communication, a multiharmonic analysis for Direction Finding based on TMA is proposed. The linear regression model of the two-element Direction-Finding system is established, and its noise covariance matrix is also analyzed. With the best linear unbiased estimator (BLUE), the high-order harmonic components which were previously ignored in the estimation can be effectively utilized to improve the Direction-Finding accuracy. Compared with conventional single harmonic analysis, simulation results are provided to demonstrate validation of the proposed method for improving the Direction-Finding accuracy. An experimental system based on two-element TMA is constructed and implemented to verify the feasibility of the proposed method.

  • Direction Finding by Time-Modulated Linear Array
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Anjie Cao, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng, Ronghong Jin
    Abstract:

    The Direction Finding method by the time-modulated linear array (TMLA) is analyzed and verified. The Direction of arrival (DOA) can be calculated out by analyzing the spectrum characteristic of the received signal after the time modulation. Its principle is as follows. Because of the periodic modulation, the fundamental and harmonic components are generated in each element simultaneously. After the combiner, the harmonic components’ characteristic of the combined signal is influenced by the DOA. Through analyzing their mathematical relationship, the DOA can be calculated out directly. Compared with the existing Direction Finding methods, the proposed method has two main advantages. One is that only a single RF channel is used, and the other is that its precision can be improved by the time accumulation. The main calculation amount of the proposed method locates in the spectrum estimation for the received signal and the matrix inversion for the harmonic characteristic matrix. Numerical simulations are provided to verify the proposed method, and the related factors influencing on the Direction Finding precision are analyzed. A simple $S$ -band eight-element TMLA is constructed and tested to verify its effectiveness. Finally, some conclusions are drawn, and the further research is sketched out.

  • Direction Finding using time modulated array
    2017 Sixth Asia-Pacific Conference on Antennas and Propagation (APCAP), 2017
    Co-Authors: Ronghong Jin, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng
    Abstract:

    Time modulated array (TMA) has received a great deal of attention recently, owing to their usefulness in numerous applications including radars, sensors and communications. Specifically, with the exploitation of harmonics, generated by periodically modulated switches, TMA is also promising candidates for Direction Finding. In this paper, we take a general review and new perspectives on the Direction Finding using TMA. Some novel ideas, such as Direction Finding with time modulated linear array, Direction Finding of linear frequency modulated signal with TMA, and 2-D Direction Finding with TMA, are presented and discussed.

  • Direction Finding by time modulated linear array
    2017 IEEE International Symposium on Antennas and Propagation & USNC URSI National Radio Science Meeting, 2017
    Co-Authors: X. Liang, Ronghong Jin, Weiren Zhu, Gunping Geng, Anjie Cao, Di Hui
    Abstract:

    A novel Direction Finding method with the time modulated linear array (TMLA) is proposed and verified, by establishing the relationship between the incident angle and the generated harmonic characteristic matrix (HCM). The principle is that the generated HCM because of the periodical modulation varies with the incident Direction of the RF signal. Compared to the existing Direction Finding method, the proposed method has simple structure and low calculation complexity. Numeric simulation is provided to examine its performance and an 8-element S-band TMLA is constructed to verify its effectiveness.

  • New precision wideband Direction Finding antenna
    IEE Proceedings - Microwaves Antennas and Propagation, 2001
    Co-Authors: X. Liang, Y.w.m. Chia
    Abstract:

    A new wideband precision Direction Finding antenna is introduced. A 7-element printed log-periodic dipole array antenna is modified to become a Direction Finding antenna by bending it into a cylindrical structure. This antenna is extremely simple and there is no need for a matching network for wideband operation. Cardioid radiation patterns are obtained and presented.

Jingfeng Chen - One of the best experts on this subject based on the ideXlab platform.

  • Direction Finding Based on Time-Modulated Array With Multiharmonic Analysis
    IEEE Transactions on Antennas and Propagation, 2020
    Co-Authors: Jingfeng Chen, X. Liang, Junping Geng, Wenzhi Wang, Ronghong Jin
    Abstract:

    Direction Finding with time-modulated array (TMA) has attracted considerable attention recently. In this communication, a multiharmonic analysis for Direction Finding based on TMA is proposed. The linear regression model of the two-element Direction-Finding system is established, and its noise covariance matrix is also analyzed. With the best linear unbiased estimator (BLUE), the high-order harmonic components which were previously ignored in the estimation can be effectively utilized to improve the Direction-Finding accuracy. Compared with conventional single harmonic analysis, simulation results are provided to demonstrate validation of the proposed method for improving the Direction-Finding accuracy. An experimental system based on two-element TMA is constructed and implemented to verify the feasibility of the proposed method.

  • Direction Finding by Time-Modulated Linear Array
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Anjie Cao, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng, Ronghong Jin
    Abstract:

    The Direction Finding method by the time-modulated linear array (TMLA) is analyzed and verified. The Direction of arrival (DOA) can be calculated out by analyzing the spectrum characteristic of the received signal after the time modulation. Its principle is as follows. Because of the periodic modulation, the fundamental and harmonic components are generated in each element simultaneously. After the combiner, the harmonic components’ characteristic of the combined signal is influenced by the DOA. Through analyzing their mathematical relationship, the DOA can be calculated out directly. Compared with the existing Direction Finding methods, the proposed method has two main advantages. One is that only a single RF channel is used, and the other is that its precision can be improved by the time accumulation. The main calculation amount of the proposed method locates in the spectrum estimation for the received signal and the matrix inversion for the harmonic characteristic matrix. Numerical simulations are provided to verify the proposed method, and the related factors influencing on the Direction Finding precision are analyzed. A simple $S$ -band eight-element TMLA is constructed and tested to verify its effectiveness. Finally, some conclusions are drawn, and the further research is sketched out.

  • Direction Finding using time modulated array
    2017 Sixth Asia-Pacific Conference on Antennas and Propagation (APCAP), 2017
    Co-Authors: Ronghong Jin, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng
    Abstract:

    Time modulated array (TMA) has received a great deal of attention recently, owing to their usefulness in numerous applications including radars, sensors and communications. Specifically, with the exploitation of harmonics, generated by periodically modulated switches, TMA is also promising candidates for Direction Finding. In this paper, we take a general review and new perspectives on the Direction Finding using TMA. Some novel ideas, such as Direction Finding with time modulated linear array, Direction Finding of linear frequency modulated signal with TMA, and 2-D Direction Finding with TMA, are presented and discussed.

Junping Geng - One of the best experts on this subject based on the ideXlab platform.

  • Direction Finding Based on Time-Modulated Array With Multiharmonic Analysis
    IEEE Transactions on Antennas and Propagation, 2020
    Co-Authors: Jingfeng Chen, X. Liang, Junping Geng, Wenzhi Wang, Ronghong Jin
    Abstract:

    Direction Finding with time-modulated array (TMA) has attracted considerable attention recently. In this communication, a multiharmonic analysis for Direction Finding based on TMA is proposed. The linear regression model of the two-element Direction-Finding system is established, and its noise covariance matrix is also analyzed. With the best linear unbiased estimator (BLUE), the high-order harmonic components which were previously ignored in the estimation can be effectively utilized to improve the Direction-Finding accuracy. Compared with conventional single harmonic analysis, simulation results are provided to demonstrate validation of the proposed method for improving the Direction-Finding accuracy. An experimental system based on two-element TMA is constructed and implemented to verify the feasibility of the proposed method.

  • Direction Finding by Time-Modulated Linear Array
    IEEE Transactions on Antennas and Propagation, 2018
    Co-Authors: Anjie Cao, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng, Ronghong Jin
    Abstract:

    The Direction Finding method by the time-modulated linear array (TMLA) is analyzed and verified. The Direction of arrival (DOA) can be calculated out by analyzing the spectrum characteristic of the received signal after the time modulation. Its principle is as follows. Because of the periodic modulation, the fundamental and harmonic components are generated in each element simultaneously. After the combiner, the harmonic components’ characteristic of the combined signal is influenced by the DOA. Through analyzing their mathematical relationship, the DOA can be calculated out directly. Compared with the existing Direction Finding methods, the proposed method has two main advantages. One is that only a single RF channel is used, and the other is that its precision can be improved by the time accumulation. The main calculation amount of the proposed method locates in the spectrum estimation for the received signal and the matrix inversion for the harmonic characteristic matrix. Numerical simulations are provided to verify the proposed method, and the related factors influencing on the Direction Finding precision are analyzed. A simple $S$ -band eight-element TMLA is constructed and tested to verify its effectiveness. Finally, some conclusions are drawn, and the further research is sketched out.

  • Direction Finding using time modulated array
    2017 Sixth Asia-Pacific Conference on Antennas and Propagation (APCAP), 2017
    Co-Authors: Ronghong Jin, X. Liang, Jingfeng Chen, Weiren Zhu, Junping Geng
    Abstract:

    Time modulated array (TMA) has received a great deal of attention recently, owing to their usefulness in numerous applications including radars, sensors and communications. Specifically, with the exploitation of harmonics, generated by periodically modulated switches, TMA is also promising candidates for Direction Finding. In this paper, we take a general review and new perspectives on the Direction Finding using TMA. Some novel ideas, such as Direction Finding with time modulated linear array, Direction Finding of linear frequency modulated signal with TMA, and 2-D Direction Finding with TMA, are presented and discussed.