An analysis of passive relay station with back-to-back antenna for radio coverage improvement inside the buildings

The passive relay station implemented with two back-to-back antennas presents a possible, simple and cost-effective solution to achieve better radio-coverage quality inside the buildings. This paper presents theoretic analysis of the back-to-back solution for such application, followed by the experimental testing of one practical solution through the extensive measurement of achieved radio-coverage characteristics of an existing PMR network inside several electrical transformer station buildings. The measurement results confirmed, to a large extent, the results of the theoretical analysis, and it is concluded that the given solution, under the certain conditions, can be successfully applied for radio-coverage improvement inside the observed and similar type of buildings.