Microwave solid-state delay lines

The low-loss propagation of microwave phonons at room temperature in certain single crystals makes practical the construction of microwave acoustic delay (MAD) lines. The properties of these solid-state units are discussed and compared to those of more conventional microwave delay devices. Various possible applications of solid-state lines are suggested and the present status of these units is reviewed. The dispersive properties of magnetoelastic and magnetostatic wave propagation are also outlined and practical considerations governing their use are discussed. Microwave acoustic delay devices not only offer size and weight advantages over conventional microwave delay lines, but also offer improved performance and in many cases lower cost than the conventional units.