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.
A low-profile curl antenna with an EBG reflector has a relatively wide input impedance bandwidth. Low-profile equiangular- and Archimedean-spiral antennas, each backed by an EBG reflector, have a wider input impedance bandwidth than the curl. A low-profile inverted F antenna above an EBG reflector radiates a tilted beam. An array composed of inverted F antennas combined with switching circuits has...
This paper describes the application of an efficient implicit finite-difference time-domain method (FDTD) based on the locally one-dimensional (LOD) scheme to the analysis of periodic band-gap structures. In particular, the technique of oblique incidence is introduced into the periodic LOD-FDTD method. To maintain a tridiagonal system of linear equations, we newly develop a three-step algorithm consistent...
The finite-difference time-domain method based on the locally one-dimensional scheme (LOD-FDTD) is extended to the analysis of periodic structures. The cyclic matrix problem resulting from the application of the periodic boundary condition to the implicit LOD scheme is efficiently solved with the Sherman-Morrison formula. The analysis of a photonic bandgap structure shows that the numerical results...
An extremely low-profile spiral antenna above a PEC reflector does not show wideband antenna characteristics. However, placing ring-shaped absorbing material between the outermost spiral arms and the PEC reflector mitigates deterioration in the antenna characteristics. Further investigation shows that removing absorbing material and replacing the PEC reflector by an EBG reflector contribute to realizing...
An efficient finite-difference time-domain method based on the locally one-dimensional scheme (LOD-FDTD) is developed for the analysis of periodic structures. The Sherman-Morrison formula is used to efficiently solve the cyclic matrix problem resulting from the application of the periodic boundary condition to the implicit LOD scheme. Through the analysis of a photonic band-gap (PBG) structure, numerical...
This paper presents a spiral antenna backed by a mushroom-shaped EBG reflector. The antenna characteristics are investigated on the basis of the electric and magnetic fields obtained by using the finite-difference time-domain method. The investigation reveals that removing some patches from the EBG reflector improves the axial ratio.
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.