This one is technically very interesting:
InjectEave differs from conventional electromagnetic eavesdropping because it does not simply listen for signals a device naturally emits. Instead, the attacker transmits a carefully selected radio-frequency signal toward the target. Nonlinear electronic components inside the device, including amplifiers, analog-to-digital converters, power converters, and switching transistors, can unintentionally mix internal analog signals with that injected carrier. The resulting radio emissions can then contain information about the original signal.
Nice portable kit:
Full research paper: https://arxiv.org/pdf/2609.04785

