Microwave photonic components and subsystems can replace or complement their electronic counterparts with a net gain in functionality, bandwidth, size, mass, complexity, and cost, facilitating the innovative implementation of radio frequency (RF) systems due to broad bandwidth, low loss, light weight, flat frequency response, favorable isolation, and immunity to electromagnetic interference (EMI) provided by photonic technologies. Much attention has been recently paid to this area, which results in impressive progresses. Hence, we designed a focus issue intended to introduce the recent advancements in this field, especially the works by some distinguished research groups.