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.
Characteristic modes (CMs) are used to design an NVIS antenna system on-board an electrically small UAV. Using the CMs of the UAV platform, near-vertical incident skywave (NVIS) are realized using pre-specified locations for antenna mounting. The appropriate excitation level of each monopole feed can be computed in a systematic manner using the CMs of the composite UAV + monopole antenna system. Discussions...
Characteristic modes are used to design a multi-antenna NVIS system on-board an electrically small UAV. By analyzing the radiation eigenmodes of the UAV platform, optimal NVIS patterns are constructed, and mounting locations which maximize desirable antenna-platform coupling are identified. The optimal NVIS pattern is then approximated using discrete monopole antennas as feeding elements. The excitation...
The design of in-situ antennas is conducted using the theory of characteristic modes. By performing a characteristic mode analysis of the supporting platform, the optimal spatial regions of antenna-platform coupling can be located, as well as approximate limits on bandwidth. Then, for a given choice of antenna, the proper feed location can be optimized rapidly based on its near-field profile, incident...
We propose a novel technique to calculate a quasi-optimal aperture excitation for finite size, ultrawideband arrays. The approach is based on using the characteristic modes of the array's mutual impedance matrix. Unlike standard excitation tapers, primarily used for beam shaping, the proposed characteristic mode taper provides for wideband matching of all array elements, including those at the edges...
Fundamental limits on the Q-factor for arbitrary-shaped PEC antennas are presented using the theory of characteristic modes. A formula for computing the Q of an arbitrary-shaped PEC antenna with an impressed current mode is derived, and is used to find minimum-Q bounds. It is shown that minimum bounds on small antenna Q can be determined simply through an eigenmode analysis of the Method of Moments...
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.