In this paper, we analyze the signal characteristics of a compact multiple antenna system. The system is composed of four symmetrically arranged element antennas for application in ultra wideband (UWB) multiple input multiple output (MIMO) environment. The compact antenna is of size 44 × 26 mm2 with high isolation (S31 < −14 dB approximately) over the frequency range of 3.8 − 11.0 GHz.
A novel defected ground structure is incorporated to enhance the isolation among the four element antennas by changing the current distribution on the ground of the four element antennas. We delineate the design principle and background ideas for the antenna, describe details of the antenna parameters, and discuss the characteristics of the antennas. Then, we tackle the problem of analyzing
the signal components from the antenna, and discuss the performance of the system in terms of scattering parameters, radiation patterns, and envelope correlation coefficients. Applications of the system for UWB MIMO environment in the areas of signal processing and communication are also indicated.