An on-chip frequency-domain analog processor inspired by frequency-scanned arrays is proposed for broadband spectrum sensing. It exploits frequency-dependent constructive and destructive interference based on an array of programmable dispersion-engineered elements. Digitally programmable dispersion is implemented with the combination of a wideband vector modulator and true-time delay line. Designed in a Global- Foundries 22FDSOI process, the IC prototype achieves a frequency scan range of 20 GHz and a resolution bandwidth of 2.6 GHz (tapering) and 2.3 GHz (no tapering), while consuming 58 mW.