Phase and delay in corporate-fed arrays
The distribution of phase and delay in corporate-fed phased arrays is examined. RMS phase errors versus scan angle are shown for digital phasers. The phaser bits should all be located at each element. The delayer bits can be also, but delayer loss, dispersion, temperature sensitivity, and size mitigate against using so many delayers. Alternative topologies, where delay bits are distributed in the corporate feed, are examined.
Time delay unit quantization at the subarray level for large, wideband linear arrays
Time delay units become larger and more expensive as the number of bits and physical size of the bits increases. The goal is to reduce the number of large bits in the array by placing them back in the feed network where they are shared my many elements. As the bits are moved back in the feed network, time delay quantization increases and produces errors in the array factor. This paper presents trade-offs between reducing the number of time delay bits and maintaining a desirable array pattern.
RDF Keyword Search based on Keywords-To-SPARQL Translation
In this paper, we present a summary of our work on RDF keyword search. Given a set of keywords, our method automatically generates a set of candidate SPARQL queries, and their natural language description, to be evaluated on the RDF data graph. We discuss our approach, highlighting current and future directions.