Latest Articles
Intelligent Microwave Staring Correlated Imaging
Kui Ying Xinyu Yu Jiana Shen Shilu Zhang Yuanyue Guo
Microwave staring correlated imaging (MSCI) is a super-resolution imaging technique based on temporal-spatial stochastic radiation fields (TSSRFs), which requires an accurate calculation of the electromagnetic field at the imaging plane. However, systematic errors always exist in practice, such as the time synchronization and frequency synchronization errors of radar systems, which make it difficult to calculate the required TSSRFs accurately, and this deteriorates the imaging results. Meanwhile, some imaging algorithms have problems such as high computational complexity. In this paper, an intelligent MSCI method based on the deep neural network (DNN) is proposed, which can accomplish imaging directly from the echoes, avoiding the computation of TSSRFs. A multi-level residual convolutional neural network (MRCNN) is developed for the DNN, and simulations and experiments are carried out to obtain the dataset for training and testing the MRCNN. Compared with the conventional MSCI methods, the imaging results verify the effectiveness of intelligent MSCI in terms of imaging quality and computational efficiency.
Intelligent Microwave Staring Correlated Imaging
Efficient Computation of Sideband Power Losses in Pulse-Shifted Non-Uniform Time-Modulated Array with Arbitrary Element Pattern
Sujoy Mandal Sujit Kumar Mandal
This paper presents the mathematical formulation for the generalized closed-form expressions to calculate sideband power (PSR) of a nonuniform period time modulated array (NTMA) antenna with volumetric geometry by using pulse shifting strategy. For the arbitrary array geometry, the generalized expression of PSR is obtained by considering the universal omnidirectional element pattern in the form sinaθ|cosθ|b, a > -1, b > -1/2. Then, corresponding to different array structures such as linear, planar, and volumetric ones, the derived expression is simplified for different element patterns with possible combination of `a' and `b'. Through representative numerical results it is demonstrated that the obtained simplified expressions without hypergeometric function are useful to accurately calculate the amount of power losses due to sideband radiations with significantly less time than the conventional numerical integration (NI) method.
Efficient Computation of Sideband Power Losses in Pulse-shifted Non-uniform Time-modulated Array with Arbitrary Element Pattern
Systematic Flexible Antenna Performance Study of V-Folding Percentage Influence
Kishore Ajay Kumar Ayyala Atul Thakur Sahbi Baccar Nour Mohammad Murad Mani S. Prasad Preeti Thakur Glauco Fontgalland Yong Zhou Blaise Ravelo
In wireless technology, microstrip patch antennas are often used in communication systems with various designs. However, the effect of geometrically folded antennas on wireless communication performance is unclear. To address this problem, an in-depth study of the flexible antenna parameters was performed through V-folding analysis. A systematic and complete analysis of the percentage of folding in patch antennas was performed. The folding of patch antennas is expected to become mandatory because patch antennas are integrated and molded according to specified object shapes. The designed antenna was operated at 0.1-5.0 GHz to investigate the folding performance in the frequency range of 1.00-3.78 GHz used in many wireless applications, such as the GPS, GSM, and LTE standards. A promising operating frequency for flat (unfold) antennas is 1.42 GHz with an achieved multiband bandwidth of 31.6 MHz, which shifted according to the folding angle but with good performance. The results of this study can be used to predict the performance of an antenna when it is placed on a product of any shape, according to the designed object pattern.
Systematic Flexible Antenna Performance Study of V-folding Percentage Influence
A Novel Decoupling Technique for Single-Layered Closely-Spaced Patch Antenna Arrays
Sai Radavaram Maria Pour
A new technique to reduce the mutual coupling between closely-spaced, single-layered patch antenna elements is presented. The proposed design comprises an integrated novel decoupling structure to generate an out-of-phase decoupling signal to effectively lower the coupling between the elements. In addition, coplanar L-probes and interdigital filter shaped slits on the ground plane are incorporated to further improve the isolation. The realized isolation level is about 28 dB at the frequency of operation. This is a significant achievement for a single-layered low-profile structure, wherein the center-to-center element spacing is only around 0.25λ0, and more importantly, no shorting vias are used.
A Novel Decoupling Technique for Single-layered Closely-spaced Patch Antenna Arrays
PIER Letters
SVD Compression and Energy Harvesting Based Energy Efficient 3D-MI-UWSNs
Sadanand Yadav Vinay Kumar
In underwater wireless sensor networks (UWSNs), the limited availability and non-rechargeability of sensor node batteries necessitated the advancement of energy optimization techniques. Optimal clustering is one such technique that reduces the energy consumption of the networks. In this letter, we propose optimal cluster compression technique jointly with energy harvesting. In optimal clustering compression, we perform optimal clustering of networks with singular value decomposition (SVD) as compression technique to reduce the redundant data generated at the cluster heads (CHs). Besides, adopting energy harvesting technique, node batteries are periodically recharged. The performance of the proposed model is evaluated in terms of network lifetime and throughput.
SVD Compression and Energy Harvesting Based Energy Efficient 3D-MI-UWSNs