scholarly journals Auto-Calibration of Co-Located Uniform Linear Array Antennas

Author(s):  
Tomas McKelvey
2013 ◽  
Vol 681 ◽  
pp. 175-180
Author(s):  
Jun Zhao ◽  
Xu Hang

The clutter distribution of airborne radar with non-sidelooking uniform linear array antennas varies with ranges and samples in different range gates are not independent identically distributed vectors, so that the statistical STAP methods degrade greatly. In this paper, an improved clutter range dependence compensation method for airborne radar with uniform linear array is proposed. This method involves in a preprocessing with ADC method to align the mainlobe of clutter spectrum in different range gates and subsequently clutter suppression in other azimuths with EDBU technology. Simulation results show the proposed method can reduce the clutter spectrum dispersion significantly and outperform conventional local compensation methods.


2014 ◽  
Vol 556-562 ◽  
pp. 3662-3665
Author(s):  
Xing Hui Chen ◽  
Shi Qiao Gao

The clutter distribution of airborne radar with non-sidelooking uniform linear array antennas varies with ranges and interference in different range gates are not independent identically distributed vectors, so the performance of statistical STAP methods degrade heavily. In this paper, the range dependency problem is studied and a clutter nonstationarity reducing method is proposed. This method involves in the pre-processing of elevation cosine based vector extending and subsequently statistical STAP technique. Simulation results show the proposed method can reduce the clutter dispersion significantly and outperform conventional compensation methods.


Author(s):  
Ahmed Abdalla ◽  
Suhad Mohammed ◽  
Tang Bin ◽  
Jumma Mary Atieno ◽  
Abdelazeim Abdalla

This paper considers the problem of estimating the direction of arrival (DOA) for the both incoherent and coherent signals from narrowband sources, located in the far field in the case of uniform linear array sensors. Three different methods are analyzed. Specifically, these methods are Music, Root-Music and ESPRIT. The pros and cons of these methods are identified and compared in light of different viewpoints. The performance of the three methods is evaluated, analytically, when possible, and by Matlab simulation. This paper can be a roadmap for beginners in understanding the basic concepts of DOA estimation issues, properties and performance.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 640
Author(s):  
Yujia Tang ◽  
Zhangjian Li ◽  
Yaoyao Cui ◽  
Chen Yang ◽  
Jiabing Lv ◽  
...  

Ultrasound plane wave imaging technology has been applied to more clinical situations than ever before because of its rapid imaging speed and stable imaging quality. Most transducers used in plane wave imaging are linear arrays, but their structures limit the application of plane wave imaging technology in some special clinical situations, especially in the endoscopic environment. In the endoscopic environment, the size of the linear array transducer is strictly miniaturized, and the imaging range is also limited to the near field. Meanwhile, the near field of a micro linear array has serious mutual interferences between elements, which is against the imaging quality of near field. Therefore, we propose a new structure of a micro ultrasound linear array for plane wave imaging. In this paper, a theoretical comparison is given through sound field and imaging simulations. On the basis of primary work and laboratory technology, micro uniform and non-uniform linear arrays were made and experimented with the phantom setting. We selected appropriate evaluation parameters to verify the imaging results. Finally, we concluded that the micro non-uniform linear array eliminated the artifacts better than the micro uniform linear array without the additional use of signal processing methods, especially for target points in the near-field. We believe this study provides a possible solution for plane wave imaging in cramped environments like endoscopy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tanzeela Mitha ◽  
Maria Pour

AbstractA novel approach to linear array antennas with adaptive inter-element spacing is presented for the first time. The main idea is based upon electronically displacing the phase center location of the antenna elements, which determine their relative coordinates in the array configuration. This is realized by employing dual-mode microstrip patch antennas as a constitutive element, whose phase center location can be displaced from its physical center by simultaneously exciting two modes. The direction and the amount of displacement is controlled by the amplitude and phase of the modes at the element level. This in turn facilitates reconfiguring the inter-element spacing at the array level. For instance, a uniformly-spaced array could be electronically transformed into a non-uniform one without any mechanical means. The proposed idea is demonstrated in two- and three-element linear antenna arrays. The technique has the potential to control the radiation characteristics such as sidelobe levels, position of the nulls, and the beamwidths in small arrays, which are useful for adaptively controlling the array performance in emerging wireless communication systems and radars.


2016 ◽  
Vol 13 (10) ◽  
pp. 1502-1506 ◽  
Author(s):  
Aaron Angel Salas-Sanchez ◽  
Maria Elena Lopez-Martin ◽  
Juan Antonio Rodriguez-Gonzalez ◽  
Francisco Jose Ares-Pena

Sign in / Sign up

Export Citation Format

Share Document