The Multipath Fading Emulator (MFE) is a software add-on for LabVIEW that helps you emulate the selective fading due to multipath propagation on microwave radio paths using the PXI Vector Signal Transceiver (VST). The MFE implements the �Two-Rays� channel model using a custom FPGA configuration for the VST. You can simulate the effect of multipath propagation on the RF channel by directly controlling the frequency and notch depth introduced by the channel model or by setting a different fractional delay of the interfering ray. You can configure the notch frequency or configure the notch depth run-time up, with a slew rate of up to 300 MHz/s and 300 dB/s respectively. Additionally, the MFE includes additional impairments including flat fading, noise, narrowband interference.