DRFM (Digital RF Memory) Jammer

Signal Chain Walkthrough

A Digital RF Memory (DRFM) jammer is a coherent electronic attack system that intercepts a threat radar's signal, digitizes and stores it, applies modifications, and retransmits it to deceive the radar. Because the retransmitted signal is a modified copy of the radar's own waveform, it passes coherent processing and appears as a legitimate target return.

Capture (ADC)

A wideband receiver intercepts the threat radar signal. A high-speed ADC (2+ GSPS, 8-12 bits) digitizes the waveform and stores it in FPGA or DSP memory. The DRFM must capture the pulse with sufficient bandwidth and dynamic range to faithfully reproduce it.

Modify (FPGA/DSP)

The stored waveform is modified before retransmission. Adding a time delay creates a false range (RGPO). Adding a frequency offset creates a false Doppler/velocity (VGPO). Multiple copies with different delays generate false targets to saturate the radar's tracker.

Retransmit (DAC + PA)

The modified waveform is converted back to analog, upconverted to the radar's frequency, and amplified for transmission. The PA must produce enough power for the false return to compete with the real target echo at the radar receiver.