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A L-band multiple-beam phased array antenna with integrated structural design for satellite usage is described in this paper. By using the integrated design, the height of the filters and the LNA modules are reduced, and all the radiating elements and modules are assembled on one integral panel. Meanwhile, a solder-less junction structure is developed between the radiating elements and the filters...
In this study, a novel symmetrical composite right/left handed meta-material unit cell is proposed. It is designed based on a circular microstrip patch which is able to work in either the left-hand region or the right-hand region. The phase constant of the unit cell is investigated. It is utilized to design a patch antenna, realizing dual-band radiation modes in a much smaller size compared to the...
The REV method based on power measurement can avoid the phase measurement, so the calibration can reach a high stability especially in high frequency. A modified method that can significantly reduce the phase-shifting error in REV method is presented in this paper. It is verified that increasing the bits of phase shifter and measuring states can reduce the effect of such error and improve the calibration...
A new combined REV calibration method for large phased array antenna is presented in this paper. This method is based on power measurement, so the measurement can reach a high stability in high frequency. It can also improve the calibration accuracy and efficiency at the same time, especially in large phased array antenna. Simulation results testify the correctness of this new method.
A novel approach to design a pattern reconfigurable antenna element to extend the scanning range of phased array by adjusting the exciting amplitude of vector antenna is presented in this paper. A 2D and 3D vector antenna composed of orthogonal electric dipoles are simulated using CST software. Simulation results demonstrate the correctness of this approach.
A compact low phase noise oscillator based on substrate integrated waveguide (SIW) structure is presented. The oscillator employs a third-degree cross-coupled bandpass SIW filter as the frequency stabilization element. Meanwhile, the groupdelay and the complex quality factor (Qsc) are all taken into consideration for the oscillator design, which is more accurate than the traditional method. The measured...
An active millimeter wave imaging system with sparse antenna array for security inspection is introduced in this review. Several key parts and related techniques of the imaging system are explained and numerical results are provided.
With graphene emerging as one of the promising materials in exploring novel and reconfigurable electromagnetic devices, in this paper, we summarize and discuss the electromagnetic property of graphene in different frequencies, as well as introduced two kinds of, namely, surface-wave and spatial-wave based electromagnetic devices base on graphene. Simultaneously, typical mechanisms for designing these...
Design of a control module for millimeter wave imaging system based on FPGA is presented in this paper. There are four parts in the module: scanning control module of antenna array, data acquisition and storage control module, ethernet transmission control module and mechanical scanning platform control module.
In this paper, an adjustable microstrip slot antenna using graphene stacks is designed for terahertz applications. And the graphene stacks consist of graphene/Al2O3 sheets, which are embedded in the microstrip substrate of the proposed antenna. According to simulation result, the frequency resonant bandwidth and radiation of the novel antenna can be dynamically modulated under different chemical potential.
A polarimetric passive millimeter wave image fusion method is proposed based on Nonsubsampled Contourlet Transform (NSCT) in this paper. The NSCT is initially applied to decompose the polarimetric passive millimeter wave images into low-frequency and high-frequency subbands, and the sparse representation and average weighted method are employed as the fusion rules for low-frequency and high-frequency...
A simple, fast, and efficient single channel passive millimeter wave (PMMW) imaging system for public security check was presented in this paper. It distinguishes itself with traditional ones by an innovative scanning structure. Indoor and outdoor experiments against human body with or without hidden items in clothes showed that imaging could be completed in 3–5s with angular resolution of about 0...
The simultaneous improvement of radiating and scattering performance of an antenna is normally considered as a contradiction. In this paper, wideband gain enhancement and radar cross section (RCS) reduction are both achieved for a conventional patch antenna by loading metamaterial in an improved way. Through a detailed investigation of loading manners, the proposed patch antenna with both improved...
A novel design of aperture-coupled microstrip antenna with broadband low radar cross section (RCS) is proposed. Hybrid frequency selective surface (FSS) structures consisting of two kinds of polarization-dependent folded split ring resonators (PDFSRRs) and square patches are utilized to replace the conventional metallic ground. By orthogonally arranging the PDFSRRs in a chessboard-like configuration,...
An efficient approach to suppress the mutual coupling of a three-element microstrip patch array and a four-element microstrip patch array is proposed using waveguided band-gap structure (WG-BGS). The waveguided band-gap structure are realized by crossed-meander-line slits, which exhibit band-gap property. By inserting the WG-BGS between the elements of coupled patch arrays, the mutual coupling of...
This paper addresses a problem of size reduction of UWB antennas. We consider the effect of various ground plane modification on achievable miniaturization rate. In order to ensure that the optimum results are obtained, rigorous EM-driven design optimization is carried out involving all geometry parameters of the respective structures. Our investigations are performed using a representative set of...
A 3D parabolic equation (PE) method has been developed to model the propagation of electromagnetic waves over knife-edge obstacles on a perfectly conducting terrain. Under the assumption of forward propagation, the Helmholtz equation for each potential component could be approximated by a wide-angle PE. Then the split-step Fourier transform algorithm is used to march the potentials from one aperture...
In this paper, we present a method for the synthesis of multiple beams sparse array pattern based on the unitary matrix method (UMP). A Hankel block matrix is constructed from the sample data of the multiple beams pattern, we can obtain the corresponding excitation for each beam and the sparse array element position through the generalized value decomposition of the equivalent matrix pencil. The numerical...
In this paper, a novel method for the optimal design of sparse concentric ring arrays (CRA) is proposed. Owing to the property of Bessel function, the synthesis of CRA can be recast as a sparse constrained approximation problem and solved with compressive sensing method. A representative numerical experiment is provided to assess the effectiveness and advantages of the proposed method in comparison...
InISAR imaging systems generally employ a multi-antenna pair model with orthogonal properties. In practical applications, there may be amplitude and phase errors in different antenna receiving channels, and the obtained ISAR target echo signal also has errors. Although several algorithms have been proposed, these algorithms can only work with no amplitude and phase error. This paper proposed an algorithm...
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