dc.title: Design of low-loss acoustic delay lines on thin-film lithium niobate dc.description.abstract: As wireless systems continue moving toward higher frequencies and greater front-end complexity, compact low-loss signal-processing components become increasingly desirable. Acoustic delay lines are attractive in this context for their ability to process RF signals in the mechanical domain, where the much lower wave velocity enables compact implementations of analog signal-processing functions. This report examines the design and simulation of low-loss acoustic delay lines on lithium niobate. The work begins with the physical principles governing piezoelectric acoustic devices, including constitutive relations, rotated piezoelectric coefficients, and the connection between crystal orientation and acoustic mode excitation. From this foundation, interdigitated transducer geometries and unidirectional delay-line structures are developed. Finite-element simulations are then used to study modal behavior and two-port electrical response, with considerations regarding confinement and suppression of parasitic modes in the passband. Impedance matching is further examined as a necessary step for evaluating device performance in a physical RF environment.