Ultrasonic guided waves (GWs) are widely used in nondestructive evaluation and structural health monitoring (SHM). In practice, many GW systems rely on phased arrays with multiple bonded piezoelectric elements, which increases wiring, electronics, power demand, and overall integration cost. Frequency Steerable Acoustic Transducers (FSATs) offer a compact alternative by embedding beam steering into the transducer through patterned electrodes: the propagation direction is selected directly by the spectral content of the actuated or received signal, a process referred to as “in-sensor” signal processing. A key limitation arises, however, when FSATs are miniaturized for practical integration: the reduced aperture typically leads to stronger sidelobes, lower directivity, and diminished angular resolution compared with larger designs. This work proposes a metamaterial-based framework in which an FSAT is combined with a surrounding metasurface region that provides additional wavefront manipulation. The metasurface is tailored to selectively attenuate unwanted wavenumber–frequency components while preserving the targeted guided-wave mode and steering direction. In this way, the integrated FSAT–metasurface module functions as a physically realized spatial–spectral filter that suppresses sidelobes and enhances robustness without increasing system-level complexity. Results from numerical studies demonstrate that the proposed FSAT–metasurface integration improves beam quality in compact transducers, achieving pronounced sidelobe suppression over a broad operating band and a corresponding increase in angular selectivity. In guided-wave data communications, these improvements translate into reduced multipath interference and more reliable directional links while maintaining a minimal transducer footprint. In wave-based analog computing demonstrations, tailored metasurface designs provide an additional degree of freedom to engineer dispersion and shape wavenumber content, enabling transfer functions that closely approximate mathematical operators such as differentiation and integration over the frequency range of interest.