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.
Previous work has employed crossed dipoles with properly designed dimensions to radiate circularly polarized waves. Placing tunable elements on the dipoles allows dynamic reconfiguration of their impedance characteristics, thus enabling control of the polarization without the need for phase shifters. The antenna reported herein allows for either left- or right-handed circular polarization, as well...
This paper proposes a method to determine CO2 concentration by measuring relative circular polarization using 2D periodic unit cells of Bezier surfaces optimized using the Covariance Matrix Adaptation Evolution Strategy. The CO2 absorption spectrum has a peak which can be useful for measurement at 4.3 µm. A filter was designed to separate circularly polarized components of light at this frequency...
Metamaterial emitters have previously been studied for controlling the angle and polarization of near-IR emissivity from a surface. Here, we investigate bianisotropic metamaterials that can be tailored to have custom angle-dependent emissivity polarization profiles in the near-IR. A genetic algorithm is employed to synthesize an electromagnetic band-gap metamaterial structure that transitions from...
A reconfigurable dual-band circularly polarizing conformal patch antenna is demonstrated in the S-band. The dual-band behavior is achieved via the implementation of reactive end-loading without the use of shorting pins or any other connection to ground. Through the integration of variable capacitive or resistive elements into the reactive end-load, it is demonstrated that the second resonance frequency...
Antennas operating in the low UHF band have conventionally required thicknesses in the tens of centimeters. Artificial magnetic conducting (AMC) substrates have been shown to reduce the profile (height) of these antennas, but at the expense of operating bandwidth. Adding tunability has restored the flexibility of dynamically adjusting the communication channel over a wide range. Here we introduce...
A flexible polarization-insensitive metamaterial absorber design with a wide field of view was proposed for mid-infrared applications. Both single-band and dual-band designs based on bilayer metallo-dielectric stacks were presented. According to the simulated results, the proposed metamaterial absorbers optimized using a GA (genetic algorithm) could provide absorptivity greater than 0.94 at the target...
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.