SBIR-STTR Award

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.

We propose an innovative approach to the design of multi-function adaptive antenna systems using signal fragmentation by short pulses (wavelets). It relies on the sampling theory, approximation theory, and numerical optimization; it has passed significant prior testing. The use of short pulses 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 the same antenna system. In Phase I, we designed a wavelet-based antenna and optimized it numerically for energy performance while maintaining the desired spectral “purity” of the composite signal. A multi-function system prototype has been fabricated and tested, confirming the theoretically predicted properties of the antenna and its broadband-ness. Phase II work includes non-isotropic antennas, multi-frequency signals, and more comprehensive optimization. The resulting improved optimization technique will be tested, validated, and provided as industrial quality software tool with documentation. Proceeding from CW to AM, FM, FSK, and chirps, we will incorporate the capacity to represent radar and communication codes, optimally trading off between spectral leakage and energy efficiency. Directional antenna prototype will be fabricated and shown to generate the desired signals with minimum error and maximum energy efficiency.