  We review our last work on dispersion-engineered heterogeneous multicore
fiber links designed to act as tunable true time delay lines for radiofrequency
signals. This approach allows the realization of fiber distributed signal
processing in the context of fiber-wireless communications, providing both
radiofrequency access distribution and signal processing in the same fiber
medium. We show how to design trench-assisted heterogeneous multicore fibers to
fulfil the requirements for sampled true time delay line operation while
assuring a low level of crosstalk, bend sensitivity and tolerance to possible
fabrication errors. The performance of the designed radiofrequency photonic
delay lines is evaluated in the context of tunable microwave signal filtering
and optical beamforming for phased array antennas.
