A modular downhole apparatus to determine a formation property, the apparatus being incorporated into a drill string comprising one or more downhole tools and drill pipe, the drill pipe being of the same or various lengths, the modular downhole apparatus comprising a first module having one or more antennas, wherein the first module has connectors on both ends adapted to connect with the drill string; and a second module having one or more antennas, wherein the second module has connectors on both ends adapted to connect with the drill string; wherein the first module and the second module are spaced apart on the drill string; and wherein one or more of the one or more antennas of one or both of the modules has a dipole moment that is tilted or transverse.