The Doppler effect has been exploited for localization of an electromagnetic interference (EMI) radio source. The differential Doppler (DD) method has been used for many decades. Another method called the direct position determination (DPD) approach showed better performance than the DD method under low signal-to-noise ratio (SNR) environments. The DPD approach uses a single step without Doppler frequency measurement whereas the DD method involves two steps: Step 1 – measurement of Doppler frequency at each receiver (RX); and Step 2 – measurement of the Doppler frequency differences among the RXs. Both DD and DPD employ multiple mobile RXs, e.g., multiple satellites. Launching and managing multiple RXs require significantly higher cost than a single-RX operation. Of course, both DD and DPD methods exploit the Doppler frequency directly or indirectly. This thesis documents research, which attempts to challenge the traditional approach where RXs are physically separated at a significantly large distance to yield better Doppler frequency effects. It covers three novel methods requiring only a single RX. The key idea is to exploit the fact that the Doppler frequency is a function of not only velocity and position vectors but also RX frequency. In other words, the main idea is to have multiple different Doppler frequency effects at a single RX by creating multiple RX frequencies with multiple RX antennas in proximity even if the EMI transmitter (TX) uses a single carrier frequency. For implementation, this new methodology uses multiple frequency mixer intelligent reflection surface (FMx IRS) antennas and a main RX antenna in proximity. To verify the effectiveness of the proposed methods, the EMI TX’s signal is assumed to be either known or unknown. In addition, the research includes simulations using a random search, instead of a computationally inefficient grid search used in DPD, for a faster convergence. Furthermore, this thesis recommends FMx IRS antennas to create a different RX frequency at a different sampling time, e.g., chirp. Finally, this thesis will verify the claims via simulation and Cramér-Rao lower bound analysis.