An RF dielectric waveguide duplexer filter module with antenna and lower and upper Tx and Rx signal transmission blocks of dielectric material attached together in a side-by-side and stacked relationship. The blocks are covered with conductive material. Antenna and Tx and Rx input/outputs are defined at opposite ends of the filter module. RF signal transmission windows define direct coupling RF signal transmission paths between the antenna and the Tx and Rx blocks and between the lower and upper Tx and Rx blocks. One or more bridges of dielectric material on the lower Tx and Rx blocks define inductive cross-coupling Tx and Rx signal transmission paths. The Tx signal is transmitted only in the direction of the antenna block or between the upper and lower Tx blocks. The Rx signal is transmitted only in the direction of the Rx RF signal input/output or between the upper and lower Rx blocks.