@article{rajagopalan_gupta_konanur_hughes_lazzi_2007, title={Increasing channel capacity of an ultrawideband MIMO system using vector antennas}, volume={55}, ISSN={["0018-926X"]}, DOI={10.1109/TAP.2007.905938}, abstractNote={Recently it was shown that co-located vector antennas can provide the same capacity increase as spatial array antennas in multiple-input multiple-output (MIMO) systems. This paper describes the design of a vector antenna consisting of a loop antenna and two orthogonal bowtie antennas for a ultrawideband (UWB) MIMO system that operates in the frequency range 3.6-8.5 GHz. Channel capacity calculations performed with the antenna operating in a rich scattering environment show that spectral efficiency of the UWB vector antenna system approaches that of the traditional spatial array. This demonstrates that vector antennas can be used in place of spatial arrays where compact UWB multiantenna systems are needed.}, number={10}, journal={IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION}, author={Rajagopalan, Ajit and Gupta, Gaurav and Konanur, Anand S. and Hughes, Brian and Lazzi, Gianluca}, year={2007}, month={Oct}, pages={2880–2887} }
 @article{konanur_gosalia_krishnamurthy_hughes_lazzi_2005, title={Increasing wireless channel capacity through MIMO systems employing co-located antennas}, volume={53}, ISSN={["1557-9670"]}, DOI={10.1109/TMTT.2005.848105}, abstractNote={Wireless networks consisting of compact antennas find applications in diverse areas such as communication systems, direction of arrival estimation, sensor networks, and imaging. The effectiveness of many of these systems depend on maximizing the reception of RF power and extracting maximum information from the incident electromagnetic (EM) wave. Traditionally, this has been achieved through multiple-input multiple-output (MIMO) systems employing a spatial array of antennas that enhance the channel capacity. In this paper, we report similar increases in channel capacity obtained through the use of vector antennas consisting of co-located loops and dipoles, which can respond to more than one component of the EM field. It is shown that systems with three- and four-element vector antennas at both the transmitter and receiver operating around the frequency of 2.25 GHz support three and four times more information, respectively, as compared to conventional systems consisting of sensors with single antennas. Comparison with a simplified theoretical model of a MIMO system with co-located antennas in a rich multipath environment shows good agreement.}, number={6}, journal={IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES}, author={Konanur, AS and Gosalia, K and Krishnamurthy, SH and Hughes, B and Lazzi, G}, year={2005}, month={Jun}, pages={1837–1844} }