Real-Time Broadband Spectrum Analysis Using SAW Devices

This letter proposes and experimentally demonstrates a broadband real-time spectrum analysis architecture using a surface acoustic wave (SAW) dispersive delay line (DDL). The signal under test is first multiplied by a chirp signal generated by a direct digital synthesis (DDS) device, and then applied to a SAW DDL matched to the chirp signal, efficiently achieving precise frequency-to-time mapping (FTTM). In contrast to digital FFT-based real-time spectrum analyzers, the proposed approach performs the core Fourier transform operation using a passive SAW device, thereby achieving considerably lower power consumption. The simulation and experimental results fully confirm that the proposed method achieves real-time spectrum analysis over an effective bandwidth of 1GHz with a frequency resolution of 100kHz for diverse signal types. The 100% probability of intercept (POI) is20~μs, which is twice the time resolution of the system.