Terahertz Source Using Heterodyned High-Power Lasers with Ultrafast Photodetector Array

Not Available An innovative broadband slot spiral design for electrically small, low profile antennas with possible bandwidth of greater than 100:1 is proposed for HF/VHF/UHF and microwave band operation. The proposed antenna, which has great potential in maximizing angle-time-frequency diversity in multi-mode airborne applications, is based on a new already been demonstrated for operation from 200 MHz to 5 GHZ without dielectric loading. Under this proposal, the existing slot spiral design will be integrated via our innovative approach with various loading options and matched terminations to develop a rugged, low cost, conformal antenna that will be about 13 inches in diameter and 0.875 inches deep for operation above 100MHz. For operating frequencies down to 30 MHz, the proposed antenna's size can be kept less than 20 inches in diameter and 1.5 inches deep, a size that can be readily incorporated into the skin of a UAV at various locations. Further size reduction can be achieved by extending the proposed concepts, if necessary. Because of the possibility to attain extremely large bandwidths (i.e. 30 MHz to 5 GHz) based on our proposed innovative extensions, the proposed antenna is a dream antenna for ultimate counter-intelligence/ECM applications and for very accurate direction finding, imaging at varying depths (within foliage) or obtaining moving target information.