The effects of multipath interference on the performance of UWB systems in an indoor wireless channel

Abstract

and inverted, compared to the radiating-basis triangular element, is introduced on this antenna (Fig. 5). The goal here is to combine the matching frequencies of the two created antennas (one with h 1 ϭ 7.5 mm, and the other h 2 ϭ 15 mm) and thus to widen the resultant bandwidth of the structure.This results in a VSWR of about 1.5 (Fig. 6) and a much better adaptation from 3 to 7 GHz (Fig. 7). By comparing these results with those obtained experimentally, a widening of the bandwidth after 7 GHz (which was not observed in the simulation, can be noted. This variation is certainly due to the phenomenon of loss adaptation related to the poor performances of epoxy at high frequencies. The fact that this antenna is fed by a broader CPW line than that of the preceding one (the wave only propagates in the substrate under the feeding line) may explain why this phenomenon was not perceived in the first antenna.The addition of the slot does not disturb the radiation pattern, in comparison with the first structure, while the efficiency is better and fluctuates around 80% over the entire bandwidth (Fig. 8). CONCLUSIONTwo new omnidirectional antennas for short-range UWB communications have been presented; the first one amply covers the WPAN standard, and the other one presents a very good adaptation and good radiation efficiency on a very broad frequency band. Both antennas are approximately the same size as a standard business card, have low manufacturing cost, and are matched to 50⍀. Optimizations of radiation pattern and tests on better quality substrate should increase the high-frequency performances of these two antennas. Figure 7 Real and imaginary parts of the input impedance PILOT: A FAST ALGORITHM FOR ENHANCED 3D PARASITIC CAPACITANCE EXTRACTION EFFICIENCY

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