LPI Property of FDA Transmitted Signal

Abstract

Frequency diverse array (FDA) produces an angle range dependent and time-varying transmit beampattern due to the small frequency increment across its array elements, which provides potential applications for secure communications and radio frequency stealth. In this article, we study the low probability of intercept (LPI) properties of FDA transmitted signals under typical passive reconnaissance techniques. First, the passive reconnaissance property of direction-of-arrival estimation for FDA transmitted signals under phase interferometry measurement is evaluated, together with the corresponding Cramér–Rao bound analysis. Second, the passive reconnaissance property of time difference of arrival and frequency difference of arrival estimation for FDA transmitted signals are also evaluated for moving platforms. Both theoretical analysis and numerical results demonstrate that FDA transmitted signal indeed achieves significantly better LPI performance than phased-array transmitted signals, which is particularly useful for military applications.