Antenna Passive Repeaters for Indoor Recovery of Microwave Cellular Signals

摘要

make the phase-shift choice uncritical when larger areas need to be covered, as improvements in certain small regions due to the choice of the proper phase shift are made at the expense of deterioration in other areas. It was observed that in the region where the repeater power dominates, the phase shift is of little consequence. In contrast, in the indoor areas where the repeater output was comparable to the signals entering through the walls, the field distribution changes considerably. The passive repeating principle was then applied in an office building environment, where cellular coverage was practically non-existent in a specific region of interest, an underground storage and parking area. After checking that sufficient signal could be received with a directional antenna from a given base station to compensate for coaxial cable losses, the passive repeater system provided the necessary cellular coverage with low installation and maintenance costs. Although situations like the one described may not be frequent, the use of passive repeaters in underground subway and pedestrian walkways may be an interesting commercial application to exploit passive repeaters for mobile service providers. While the analysis in this article stressed the improvement in signal coverage in an extended area (mobile situation), for the case of fixed-terminal communication systems the signal level can be further increased using more directive repeater antennas or antenna arrays that cover only certain angular positions.