The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
For detecting the deception jamming that produced based on a digital radio frequency memory (DRFM) device, a novel jamming detection approach is proposed based on singular spectrum analysis (SSA). Firstly, the phase quantization model of the jamming is built and the spectrum of the quantized jamming is analyzed subsequently. The spectrum analysis result of the quantized jamming shows that the jamming...
In this paper, a design of compact ultra-wideband (UWB) bandpass filter with a ultra-narrow notched band is presented. The UWB frequency responses are achieved by using a microstrip-CPW broadside coupling structure. And a pair of side-coupled short-circuited microstrip lines is introduced to generate an ultra-narrow notched band. Based on this design, by loading a pair of varactor diodes at the end...
This paper presents a compact dual-polarized aperture-coupled filtering antenna with embedded filtering circuits, using a Jerusalem-cross microstrip radiator and a novel aperture-coupled feeding structure. A square ring slot has been adopted to implement the coupling mechanism. It is excited by two orthogonal microstrip feedlines to achieve dual polarizations. The aperture-coupled feeding network...
In this paper, an analytical solution shows that an ultrathin anisotropic ε-near-zero (AENZ) metamaterial (MM) layer backed by a metallic substrate can perfectly absorb an incident plane wave at a critical angle. The perfect absorption angle can be controlled by changing the loss of the AENZ MMs. An ultrathin microwave absorber is designed using meander-line MMs with a thickness of only λ/29. By changing...
This paper presents a printed microstrip-fed heart-shaped monopole antenna for ultra-wideband (UWB) applications. The printed monopole antenna consists of a heart-shaped radiating patch with a microstrip feeding line and an elliptical curved ground plane to improve the impedance bandwidth. Commercial software ANSYS HFSS is used to analyze and design this antenna. Measured results of the fabricated...
A novel cylindrical lens antenna operating at millimeter-wave (mm-wave) frequencies has been designed for maritime high-speed wireless communications. It is composed of a cylindrical modified Luneberg lens and a planar feed linearly-tapered slot antenna (LTSA). The cylindrical modified Luneberg lens consists of two parallel plates which are partially filled with Polytetrafluoroethylene (Teflon). The...
The stitching quality of Doppler Beam Sharpening (DBS) image will be greatly affected due to the non-ideal movement of the radar platform. A novel method based on affine transformation is proposed, which can correct and stitch the DBS image effectively. The change of attitude of the carrier aircraft could be corrected with rotation angle and the change of position of the carrier aircraft could be...
An feasible SQP method is proposed to solve general optimization problems with equality and inequality constraints. First, we transform the original problem to an associated simpler problem with only inequality constraints, and the simplified problem is shown to be equivalent to the original problem under the mild condition. Then we use feasible SQP method to solve the latter problem. Here, we use...
We propose a new class of trust region method with a self-adaptive trust region radius update rules. Trust region radius is automatically adjusted according to the weighted sum of the ratios between the actual reduction and the prediction reduction. At some assumptions, the global convergence are proved. Finally, numerical experiments show that the method is robust and effective.
We propose a trust region modified BFGS method that employs the filter technique. At some assumptions, the global convergence is proposed to a first-order stationary point and a second-order stationary point.
We propose a new trust region method that employs both the modified BFGS update and Amijio line search. The method exploits the information of function and gradient, and ensures the Hessian matrix of trust region subproblem positive-definite. At some assumptions, the global convergence and superlinear convergence property are proposed. Finally, numerical experiments show that the method is efficient.
We propose a new switching method for unconstrained minimization. The method is based on the quasi-Newton updates of Hiroshi Yabe, Hideho Ogasawara and Masayuki Yoshino. The eigenvalues and condition numbers of the modified SR1 update and the modified BFGS update are evaluated and used in the switching rule. When the condition number of the former is superior to that of the latter, the step is the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.