Godkända
Design and evaluation of a dielectric multi-mode antenna array for MIMO applications
Jonas Långbacka (E05)
Start
2008-01-07
Presentation
2011-05-04 16:15
Plats:
E:2311
Avslutat:
2011-05-24
Examensrapport:
(Kontakta handledare)
Sammanfattning
In today's wireless networks, multiple antennas at the receiver and the transmitter has become the key technology for enabling high-speed data transfer. In conventional systems this has been achieved with common antenna arrays such as dipole and monopole arrays. But as these antennas typically require an inter-element spacing of half a wavelength, they become impractically large. Design of antennas for compact solutions is therefore a challenge within this eld. As a possible solution for this challenge, we will rst show how antenna elements with orthogonal radiation patterns can be co-located to minimize space requirements. This powerful concept is exploited by inserting a quarter wavelength monopole antenna into a dielectric resonator antenna (DRA). This results in a tri-polarized multimode antenna requiring the space of only one antenna. Furthermore, two such tri-polarized elements are combined to form an array. Thus we have a 6-port antenna array exploiting both polarization and space diversities. Our application of interest is wireless computer networks, and the design was chosen for 2.65 GHz. The dielectric waveguide model will be used to estimate initial dimensions of the DRA. The antenna design will be further analysed using nite element computer models. Here we will show the advantage of having an eigenfrequency solver available in addition to the commonly used frequency domain solver when simulating multimode antennas. In order to estimate the channel capacity, a measurement campaign was conducted. The measurement was conducted in an oce environment under both line-of-sight (LoS) and non-LoS (NLoS) conditions. For the purpose of performance comparison, the measurement campaign also included a monopole array and a patch array in addition to the DRA array. We nd that the tri-polarized DRA array can achieve the same performance as a co-polarized monopole array with sparsely separated elements in a rich scattering NLoS environment.
Handledare: Thomas Bolin (Sony Ericsson)
Examinator: Buon Kiong Lau (EIT)