Analysis and Design of Adaptive Multi-Function Antenna Systems Based on Signal Fragmentation

We propose an innovative mathematical approach to the analysis and design of multi-function adaptive antenna systems. It uses the idea of signal fragmentation that has passed significant prior testing and employs the methods and results from sampling theory, approximation theory, and numerical optimization. The fragmentation of a signal into a combination of short elementary pulses (wavelets) allows the radiation of long waves by small size antennas/arrays, which would otherwise be inefficient. This, in turn, enables performing various diverse tasks, e.g., radar imaging and telecommunications, by one and the same compact antenna system. During Phase I, we will first consider CW signals. Our key goal is to optimize the energy performance of the array while maintaining the desired spectral ``purity'' of the composite signal and satisfying some additional constraints on its shape (related, e.g., to bounds on the input current rise times). We will then expand into AM and FM signals, including FMCW, chirped pulses, frequency-shift keying (FSK), and Baker codes (e.g., direct-sequence spread spectrum (DSSS) modulation). We will also use the results to design and fabricate an isotropic antenna prototype. Phase II will include non-isotropic antennas (analysis and fabrication), more comprehensive optimization, and development of a well-documented “sharable” software package.