A position tracking system for tracking a physical location of a radio frequency (RF) transmitter comprises at least four RF receiver antennae at known locations. Each receiver antenna receives RF signals from the RF transmitter. One receiver antenna is used as a reference antenna. A receiver channel unit is in communication with the RF receiver antennae. The receiver channel unit comprises a reference receiver channel and a measurement receiver channel. A multiplexer is dynamically configurable to selectively connect the reference receiver channel to the reference receiver antenna and to connect, in succession, each other receiver antenna to the measurement receiver channel. A comparator measures phase differences between the RF signals received by the reference antenna and those received by each other receiver antennae. A data processor computes the physical location of the RF transmitter from the phase differences measured by the comparator and the known locations of the receiver antennae.