scholarly journals Array Antenna Design for Passive Coherent Location Systems with Non-Uniform Array Configurations

2020 ◽  
Vol 20 (3) ◽  
pp. 176-182
Author(s):  
Doyoung Jang ◽  
Jun Hur ◽  
Hongsuk Shim ◽  
Junsik Park ◽  
Chihyun Cho ◽  
...  
Keyword(s):  
Antenna Array ◽  
Target Detection ◽  
Side Lobe ◽  
Detection Performance ◽  
Array Antenna ◽  
Antenna Design ◽  
Circular Array ◽  
Uniform Array ◽  
Location Systems ◽  
Antenna Characteristics

This study investigates non-uniform array configurations to maximize the beamforming performance of passive coherent location (PCL) systems. The proposed array consists of eight dipole elements that are divided into two groups with different distances from the array center. This double-layered non-uniform configuration is designed considering the array antenna characteristics (peak-to-side lobe ratio, first null bandwidth, null width, and null depth). The resulting antenna array can provide more appropriate patterns for PCL systems than a conventional uniform circular array. The target detection performance of the proposed array in PCL systems is tested in a certain scenario. The results demonstrate that the proposed antenna in PCL systems can detect the target with Doppler and range errors of 1 Hz and 1.2 km, respectively, in a given situation.

Research on Beamforming Technique for Communications in Moving of Warship Circular Array Antenna

2012 ◽  
Vol 241-244 ◽  
pp. 2295-2298
Author(s):  
Qing Hua Wu ◽  
An Qing Zhang
Keyword(s):  
Antenna Array ◽  
Array Antenna ◽  
Beam Forming ◽  
Circular Array ◽  
Null Steering ◽  
Beam Directivity ◽  
Beamforming Technique ◽  
Maximum Directivity ◽  
Circular Array Antenna ◽  
Circular Antenna Array

Uniform circular antenna array of warship can bring beam and interference null steering from 360° symmetry without rotating. Directional communications can be achieved by UCA geometry. To solve the problem that warship’s stance is changed dynamically in course of sailing, a method was suggested that the electricity phases of UCA elements were changed based on information of stance about longitudinal sway, transverse sway and course. The proposed method can change beam directivity, and ensure providing a very directive pattern with stabilization, so that warships communication in moving each other. An expression of array maximum directivity forming with dynamic is proposed for UCA antenna. The simulation demonstrates that the beam forming method of communications in moving is validity, and is worth using with wide application.

scholarly journals Optimum concentric circular array antenna with high gain and side lobe reduction at 5.8 GHz

2017 ◽  
Vol 260 ◽  
pp. 012038 ◽  
Author(s):  
Mohammed Zaid ◽  
Md Rafiqul Islam ◽  
Mohamed H Habaebi ◽  
AHM Zahirul Alam ◽  
Khaizuran Abdullah
Keyword(s):  
Side Lobe ◽  
High Gain ◽  
Array Antenna ◽  
Circular Array ◽  
Circular Array Antenna

scholarly journals Antenna array synthesis using a newly evolved optimization approach: Strawberry algorithm

2019 ◽  
Vol 70 (4) ◽  
pp. 317-322 ◽  
Author(s):  
Konidala R. Subhashini
Keyword(s):  
Antenna Array ◽  
Optimization Technique ◽  
Beam Width ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Optimization Approach ◽  
Circular Array ◽  
First Time ◽  
Antenna Array Synthesis

Abstract An attempt has been made for the first time to apply this proposed Strawberry optimization technique to antenna array synthesis problem. The case study cited here refer to linear and circular array configurations. The design constraints are limited to minimizing the side lobe level and restricting the first null beam width, which play significant roles in antenna array performances. The key parameters which greatly influence in achieving the said objectives are either placement of antenna elements or amplitudes of excitations of these elements or both. And the recently reported meta heuristic nature inspired optimization algorithms have addressed to these problems quite effectively and the exciting result obtained using the said approach has undoubtedly proved the strawberry algorithm as a potential contender in the optimization domain.

scholarly journals Frequency scanning antenna arrays with pentagonal dipoles of different impedances

2015 ◽  
Vol 12 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Nikola Boskovic ◽  
Branka Jokanovic ◽  
Aleksandar Nesic
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Scanning Angle ◽  
Frequency Scanning ◽  
Wide Range ◽  
Scanning Antenna ◽  
Antenna Characteristics

In this work we present the benefits of using pentagonal dipoles as radiating elements instead of classical printed dipoles in the design of frequency scanning antenna arrays. We investigate how impedance of pentagonal dipoles, which can be changed in a wide range, influences the overall characteristics of the uniform antenna array. Some very important antenna characteristics such as side lobe level, gain and scanning angle are compared for three different antenna arrays consisting of identical pentagonal dipoles with impedances of 500 ?, 1000 ? and 1500 ?.

scholarly journals Effects of Inter-Element Spacing and Number of Elements on Planar Array Antenna Characteristics

2018 ◽  
Vol 10 (1) ◽  
pp. 230
Author(s):  
Noor Hidayah Muhamad Adnan ◽  
Islam Md. Rafiqul ◽  
AHM Zahirul Alam
Keyword(s):  
Massive Mimo ◽  
Lower Half ◽  
Array Antenna ◽  
Antenna Design ◽  
Main Lobe ◽  
5G Networks ◽  
Innovative Solutions ◽  
Planar Array ◽  
Half Power ◽  
Antenna Characteristics

<p>Planar array antenna is seen as one of the innovative solutions of massive MIMO and 5G networks since they provide directive beams. In this paper, planar array antenna with square and rectangular arrangements based on 2 x 2 antenna elements as one subarray was proposed. Then, array factor for the the planar array antenna with up to 64 antenna elements was calculated to analyze the effects of inter-element spacing and number of elements on the antenna characteristics. Higher values of inter-element spacing contributed to higher number of side lobes, narrower main lobe, higher directivity and lower half power beamwidth (HPBW). Inter-element spacing equals to 0.5λ was found to be the most suitable value for planar array antenna design based on the analysis. Meanwhile, higher number of antenna elements increased the value of directivity of the planar array with narrower HPBW. Therefore, there is a tradeoff between directivity and HPBW in designing planar array antenna for massive MIMO application.       </p><p> </p>

scholarly journals Implementation of a Modified Faster R-CNN for Target Detection Technology of Coastal Defense Radar

2021 ◽  
Vol 13 (9) ◽  
pp. 1703
Author(s):  
He Yan ◽  
Chao Chen ◽  
Guodong Jin ◽  
Jindong Zhang ◽  
Xudong Wang ◽  
...  
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Target Detection ◽  
Real Data ◽  
Detection Performance ◽  
Detection Accuracy ◽  
Constant False Alarm Rate ◽  
Data Set ◽  
Detection Technology ◽  
Coastal Defense

The traditional method of constant false-alarm rate detection is based on the assumption of an echo statistical model. The target recognition accuracy rate and the high false-alarm rate under the background of sea clutter and other interferences are very low. Therefore, computer vision technology is widely discussed to improve the detection performance. However, the majority of studies have focused on the synthetic aperture radar because of its high resolution. For the defense radar, the detection performance is not satisfactory because of its low resolution. To this end, we herein propose a novel target detection method for the coastal defense radar based on faster region-based convolutional neural network (Faster R-CNN). The main processing steps are as follows: (1) the Faster R-CNN is selected as the sea-surface target detector because of its high target detection accuracy; (2) a modified Faster R-CNN based on the characteristics of sparsity and small target size in the data set is employed; and (3) soft non-maximum suppression is exploited to eliminate the possible overlapped detection boxes. Furthermore, detailed comparative experiments based on a real data set of coastal defense radar are performed. The mean average precision of the proposed method is improved by 10.86% compared with that of the original Faster R-CNN.

scholarly journals Clutter Cancellation and Long Time Integration for GNSS-Based Passive Bistatic Radar

2021 ◽  
Vol 13 (4) ◽  
pp. 701 ◽  
Author(s):  
Binbin Wang ◽  
Hao Cha ◽  
Zibo Zhou ◽  
Bin Tian
Keyword(s):  
Fourier Transform ◽  
Target Detection ◽  
Time Integration ◽  
Detection Performance ◽  
Bistatic Radar ◽  
Detection Range ◽  
Robust Detection ◽  
Coherent Integration ◽  
Long Time ◽  
Long Time Integration

Clutter cancellation and long time integration are two vital steps for global navigation satellite system (GNSS)-based bistatic radar target detection. The former eliminates the influence of direct and multipath signals on the target detection performance, and the latter improves the radar detection range. In this paper, the extensive cancellation algorithm (ECA), which projects the surveillance channel signal in the subspace orthogonal to the clutter subspace, is first applied in GNSS-based bistatic radar. As a result, the clutter has been removed from the surveillance channel effectively. For long time integration, a modified version of the Fourier transform (FT), called long-time integration Fourier transform (LIFT), is proposed to obtain a high coherent processing gain. Relative acceleration (RA) is defined to describe the Doppler variation results from the motion of the target and long integration time. With the estimated RA, the Doppler frequency shift compensation is carried out in the LIFT. This method achieves a better and robust detection performance when comparing with the traditional coherent integration method. The simulation results demonstrate the effectiveness and advantages of the proposed processing method.

Sign in / Sign up

Export Citation Format

Share Document