Dielectric lens antennas can be designed to produce highly shaped beams that significantly improve the performance of emerging wireless indoor millimeter wave systems. A lens configuration is analyzed in this paper that produces a circular symmetric cell with uniform spatial distribution of power, with fairly sharp boundaries and scalable cell radius. The last characteristic is used to control the reflections at side walls. An hemispherical coverage lens antenna is designed for the mobile terminal to ensure relatively free movement. The impact of these antenna is analyzed in terms of cell coverage and channel time dispersion, considering the effect of cell radius scaling, and mobile terminal antenna tilting. Measurements and simulations show that the proposed lenses outperform common solutions based on pyramidal horns or biconics.