Diversity Techniques with Dipole Antennas in Indoor Multipath Propagation

Diversity Techniques With Parallel Dipole Antennas: Radiation Pattern Analysis

“…The antenna de-correlation distance is significantly affected by the mutual coupling. Measurements in the past [1] and our recent research [4] show that closely spaced dipole antennas (0.05 wavelengths apart) can still give a low signals correlation, in contrast to previous work on uncoupled dipoles showing that 0.5 wavelengths spacing is needed.…”

“…In practical diversity applications, the antennas are both matched to 50Ω source impedances. When the antennas are brought closer, the mutual coupling between the antennas is increased [4]. As a result, the coupling alters somewhat the current (amplitude and phase) along the antennas.…”

“…Now we consider the following cases: 1) If the dipole spacing is more than one wavelengths (d > λ), the mutual power coupling between the antennas is too small (less than −18 dB) [4]. The far-field patterns are similar.…”

“…The far-field patterns are similar. Therefore, the couplingpattern amplitude is theoretically given by the square of the element factor of an isolated dipole (i.e., |C(Ω)| = [A cos(π/2 cos θ)/ sin θ] 2 ); the coupling-pattern phase is generated due to their different locations i.e., ∆Φ(Ω) = 0 in (4). By this assumption, the signal correlation Correlation coefficient as a function of the dipole spacing (wavelength), simulated and measured inside an isotropically scattered field environment, (---) theoretical calculated; (...) overall simulated; (-) simulated using amplitude-pattern diversity effects; (-.…”

“…In recent years, there has been increasing use of reverberation chambers for wireless antenna tests in multipath environments [4,[13][14][15][16]23]. The measurements in the present paper are performed in Supelec reverberation chamber.…”