Small-size and low-cost wideband 800 MHz delay line tunable from 1.3 ns to 1.67 µs for automotive radar sensor

A small-size and low-cost wideband delay line tunable over a 1250:1 delay range is presented in this paper. The delay line should take place afterward in an automotive radar target simulator. The initial specifications require merging different technologies to simulate the desired distances from 0.2 m to 250 m with a high resolution and a large frequency band better than 800 MHz. Three technologies are highlighted, SAW filters, optical fibers and LTCC components, to generate delays between 1.3 ns and 1.67 μs. Prototypes were realized, tested and characterized for each technology. Moreover, a hybridization of these technologies is proposed together, with the whole delay line simulations.